Bioreactor and method of cleaning

Abstract

Bioreactor (1) comprising a tank (10) for growth medium (12), and a plurality of grow modules provided within the tank (10), wherein each of the plurality of grow modules (14, 14a, 14b, 14c) comprises either at least a first guide element (20), a second guide element (22), and a third guide element (24), the guide elements (20, 22, 24) being mounted to each other, or at least a first guide element (20), a second guide element (22), a third guide element (24), and a guide element support structure (16) to which the guide elements (20, 22, 24) are mounted to form the respective first grow module (14, 14a, 14b, 14c). The guide elements of a grow module are, respectively, disposed next to each other in a first direction of the grow module and form a first flow chamber (26) defined between the first and the second guide elements (20, 22) and a second flow chamber (28) defined between the second and the third guide elements (22, 24). Each of the plurality of grow modules is, with the guide elements (20, 22, 24) being mounted to each other or mounted to the guide element support structure (16), removably provided within the tank (10). At least one of the plurality of grow modules (14, 14a, 14b, 14c) is removable from the tank (10) separately from at least another one of the plurality of grow modules (14, 14a, 14b, 14c).

Description

TITLE: BIOREACTOR AND METHOD OF CLEANINGFIELD OF THE INVENTION

[0001] The present invention relates to a bioreactor and its cleaning method, in particular a photobioreactor, even more particular to an airlift photobioreactor, for cultivating organisms, especially photoautotrophic organisms. More specifically, it pertains to a bioreactor designed for growing microalgae, cyanobacteria, macroalgae, and some mosses within a liquid growth medium, which is preferably irradiated by artificial light sources.BACKGROUND OF THE INVENTION

[0002] Bioreactors, in particular photobioreactors, may be implemented as open systems in which, for example, a tank or basin which is open to the environment and exposed to sunlight, contains a growth medium in which the organisms are grown. In contrast, closed system bioreactors, a growth medium (also known as culture medium) is circulated within a closed circulation system such that the growth medium is normally not exposed to the environment. Closed system (photo-) bioreactors avoid water losses, minimize contamination, and enable the relevant factors for effectively growing the organisms (photosynthesis-relevant factors) to be more precisely controlled (regulated). The photosynthesis-relevant factors are, in particular, the exposure of the growth medium to (preferably controllable artificial) light and the input of CO2 into the growth medium. Furthermore, it is important that the growth medium is constantly mixed (agitated) such that the light exposure and the input of CO2 are homogenously distributed over (throughout) the growth medium.

[0003] An example of a closed system photobioreactor known in the art is a so-called flat panel airlift photobioreactor (FPA) as manufactured by Subitec GmbH, Stuttgart, Germany. Such photobioreactors are generally formed of two housing shells, which are connected to each other such that a hollow upflow chamber is formed between the two housing shells. The FPA is formed such that an upflow path from bottom to top through the upflow chamber has a waveform (meander) shape. The bottom of the FPA comprises a membrane to introduce CO2 into the upflow chamber. Furthermore, downflow means are provided to allow a downflow (return) of the growth medium to the bottom of the tank. Several FPAs may be arranged as an array / stack for mass cultivation.

[0004] In operation, such FPAs are filled with a growth medium. By introducing CO2, a waveform-shaped upward flow of growth medium through the flow path is created (airlift). By irradiating (illuminating) with artificial light, the organisms in the culture will grow (proliferate). The airlift and the waveform-shape enable a high degree of homogenization of the growth medium during the cultivation process.

[0005] FPAs are described, for example in WO 2017 / 055585 Al. Similar photobioreactors are, for example, described in DE 199 16 597 Al (and its English-language family member US 6,509,188 Bl), and US 7,374,928 B2.SUMMARY OF THE INVENTION

[0006] The interior of closed system bioreactors, including FPAs, must be cleaned from time to time because a biofilm typically forms (grows) on the inside surfaces of the structure holding the growth medium. Known cleaning processes are e.g., rinsing, e.g., with chemicals, and / or hot steam injection (pressure washing). However, the removal of biofilm is difficult to perform in an efficient manner and is thus time consuming.

[0007] Known closed system bioreactors are limited in size, creating a need for scalable bioreactors capable of processing large volumes of growth medium.

[0008] At the same time, the above photosynthesis-relevant factors should be met with a high degree of precision in order to ensure efficient production (cultivation).

[0009] It is one non-limiting object of the present invention to disclose an improved bioreactor and a cleaning method for such a bioreactor.

[0010] This object is solved by bioreactors according to claim 1 or 17 and methods of cleaning according to claims 16 or 20. Further developments are given in the dependent claims.

[0011] The bioreactor according to claim 1 comprises a tank and a plurality of grow modules provided therein. The tank should encompass without limitation basins, pools, containers and any type of similar device for holding a significant amount of liquid therein. Preferably, the tank provides a sealed volume configured to hold a liquid growth medium. The plurality of grow modules includes at least two grow modules, preferably at least three grow modules, more preferably more than ten, or more than 20 or even more than 50 grow modules. Each ofthe grow modules comprises at least three guide elements (e.g., a group of guide elements, array, stack). These guide elements are preferably generally plate shaped. Between adjacent guide elements, flow chambers for growth fluid are defined.

[0012] The (fluid) flow chambers are configured to allow a growth fluid to flow, preferably, at least in the vertical direction, and therefore define corresponding (fluid) flow paths. The second guide element of each grow module, which is provided between the first guide element and the third guide element, partially defines two (fluid) flow chambers.

[0013] The plurality of grow modules is preferably provided separately removably in the tank. Preferably, they are provided in the tank in a non-destructively detachable and, preferably, re-mountable (re-attachable) manner. For example, the grow modules and walls of the tank comprise engagement structures for fixing the grow modules. Alternatively, fixing means like hooks, latches, screws, adhesive, magnets are provided. Grow modules not provided adjacent to a tank wall may be mounted / fixed to one or more adjacent grow modules. According to a further possibility, fixing means like a support beam may be provided on top of or on a bottom surface of the tank for fixing the grow modules thereon. According to a further alternative or in addition, grow modules may also freely float in the grow medium. In this case, they may be oriented by cables or ropes.

[0014] Each grow module is preferably removable as a unit separate to another grow module and preferably without de-mounting components of the respective grow module. Thus, in a preferred embodiment, the grow modules may be lifted separately from each other out of the tank, by, for example, a lifting crane or any other lifting device, which may be part of the bioreactor or bioreactor system. Also, according to a preferred embodiment, a subset of grow modules may be connected to each other and may be lifted (removed) out of the tank together but independent from at least another one of the grow modules.

[0015] This claimed configuration provides a bioreactor which addresses the known issues by offering a scalable bioreactor solution with a simple, modular structure. The solution is scalable because only the size of the tank limits the number of grow modules forming the flow chambers which are finally determining the capacity of the bioreactor. By providing the grow modules such that they are removable independent from each other, the grow modules can be maintained independently of each other and preferably while the grow modules remaining in the tank remain in operation. Furthermore, a subset of grow modules may be maintained at the same time. This design allows for reducing or even avoiding downtime andenhancing operational efficiency. The modular approach also supports customization and scalability, accommodating different production scales and requirements while allowing optimization of potential flow dynamics through improved airlift mechanisms.

[0016] The present disclosure is not limited to the features of the independent claims combined with other features, but should encompass also the independent inventions and features described in the following, which may also be combined with each other if not described to the contrary:

[0017] A guide element may be integrally formed (in one-piece) or may be formed with or mounted to more than one member. If a guide element is made of more than one member, the members may be non-separably connected or may be separable (readily detachable) from each other.

[0018] The tank may be a separate structural member or may be formed (configured) as an integral part of another means (component) of the bioreactor system. The tank may preferably be shaped as a rectangular cuboid. In such an embodiment, the tank has a bottom wall, four side walls (two lateral side walls and a front side wall and a rear side wall) and optionally an upper wall or cover. In alternative embodiments, the tank may have any other shape such as, for example, a cylindrical shape or other type of curved and / or polygonal shape.

[0019] Preferably, two guide elements arranged next to each other in a first direction are spaced apart by gap having a first distance, preferably in the longitudinal direction. The first distance (gap) provides that the flow chamber is formed (defined) between the two guide elements. The flow chamber between two adjacent guide elements is, thus, at least in the first direction (preferably longitudinal or lateral direction), defined by the two guide elements. Preferably, the flow chamber is an open-ended flow chamber which is at least open at its lower end and its upper end in the vertical direction.

[0020] Preferably, the grow modules are provided, preferably mounted, in the tank, preferably, at least partly within a sealed volume of the tank. Preferably, the bioreactor has a predetermined (minimum) operation filling level, wherein the sealed volume is at least partly filled with growth medium. Preferably, the grow modules are provided within the tank in such a manner that the flow chambers between adjacent guide elements are at least partly filled with growth medium, when the growth medium is filled to the predetermined operation filling level. With other words, the guide elements are preferably completely or partly immersed inthe tank, when the tank is filled with the growth medium to the operation filling level. The flow chambers, which are formed (defined) between adjacent ones of the three guide elements are configured to allow a fluid flow, at least in the vertical direction preferably with components in the other directions. Thus, a flow path is defined by the flow chamber. Preferably, the flow chambers have at least two openings (entry / exit) opening into the (remaining) sealed volume of the tank. Preferably, the flow path extends at least from the entry to the exit. The guide elements are not necessarily fully immersed in the growth medium. In this case, the upper opening into the (remining) tank volume may for example, be formed laterally (open to a second direction perpendicular to the first direction and to the vertical direction) between the two guide elements forming the flow path.

[0021] Preferably a (first or last (in the first direction)) guide element of a grow module is provided for forming (defining) a (fluid) flow chamber between itself and a tank side wall or between itself and a first or last guide element of an adjacent grow module. Preferably, an additional sealing means such as a rubber lip (seal, gasket) may be provided to seal said flow chamber to other spaces.

[0022] Preferably, the guide elements of a grow module are arranged next to each other (side- by-side) in the first direction such that an array (stack, series) of guide elements is formed, wherein the array (stack) direction is the first direction. The first direction is preferably either a longitudinal direction of the bioreactor or a lateral direction of the bioreactor. The second direction (which is perpendicular to the first direction) is the corresponding other direction of the longitudinal or lateral directions. The longitudinal and lateral directions (as well as the first and second directions) are preferably perpendicular to the vertical direction of the bioreactor. With other words, the guide elements of each grow module are arranged next to each other in a first direction. The grow modules are oriented in the bioreactor such that the guide elements are arranged next to each other in the longitudinal direction and in the lateral direction of the bioreactor. Accordingly, the bioreactor may comprise grow modules which are rotated by 90 degrees to each other about the vertical direction. Thus, the guide elements of one grow module may be in parallel to the guide elements of another grow module or the guide elements of one grow module may be arranged perpendicular (rotated by 90 degrees about the vertical direction) to the guide elements of another grow module. The first and second directions preferably rotate with the corresponding grow module with respect to the bioreactor while the longitudinal direction and the lateral direction may be fixed with respect to the bioreactor. In an alternative, the coordinate systems of the bioreactor and the growmodule are independent from each other. In this case, a vertical direction of the grow module (also denoted as third direction) may differ from the vertical direction of the bioreactor. In this case, the grow modules are arranged inclined with respect to the vertical direction of the bioreactor.

[0023] According to a first alternative of claim 1, each of the grow modules may be formed by connecting the at least three guide elements of a grow module to each other in a first direction, to preferably form a unit. In this case, the guide elements (or a subset thereof) are preferably directly connected to each other by providing direct connection means supporting a direct connection. Direct connection means should encompass without limitation one or more screws, bolts, rivets, or pins. These may be used with or without washers and locking features. Further alternatives are clamps, clips, or brackets. These may be adjustable or fixed. Further alternatives are snap-fit connections relying on flexible elements that engage with corresponding features or interlocking features including dovetails, mortise and tenon joints, or other similar arrangements. Further alternatives are button-connections, magnets, engagement portions like protrusions or hooks and engaged portions like grooves which are provided on adjacent guide elements. The direct connections means can be freely combined with each other. Preferably, the direct connection means is a quick lock system allowing a quick release of the connection. The connection is preferably non-destructively detachable and, preferably, re-mountable (re-attachable). Preferably, a connection is realized by providing the direct connections means in or on side connection walls.

[0024] According to a second alternative of claim 1, which is independent of the first alternative, each grow module comprises a support structure to which the guide elements are mounted. This alternative is not limited to the case that all guide elements are directly mounted to the support structure but also encompasses the possibilities that some or preferably all of the guide elements are respectively mounted to the support structure via a third part. For example, the guide elements are mounted by a mounting means which encompasses, without limitation, one or more screws, bolts, rivets, or pins. These may be used with or without washers and locking features. Further alternatives for mounting means are clamps, clips, or brackets. These may be adjustable or fixed. Further alternatives are snap-fit connections relying on flexible elements that engage with corresponding features or interlocking features including dovetails, mortise and tenon joints, or other similar arrangements. Further alternatives are button-connections, magnets, engagement portions like protrusions or hooks and engaged portions like grooves which are provided on adjacent guideelements. The mounting means can be freely combined with each other. Preferably, the mounting means is a quick lock system allowing a quick release of the connection. The connection is preferably non-destructively detachable and, preferably, re-mountable (reattachable. Preferably, a connection is realized by providing the direct connections means in or on the side walls. Preferably, the guide element and the support structure form a unit which can be removed (in one piece) and independent from another grow module from the tank. The support structure may be formed, for example, of bars, pipes or profiles, preferably forming a frame for holding or supporting the guide elements.

[0025] The first and second alternatives should not be interpreted to exclude that the bioreactor comprises grow modules of both alternatives or even additional other types of other grow modules or even groups of guide elements which may not be considered to form a unit or even single guide elements. Preferably, claim 1 is to be interpreted to require at least a plurality of grow modules of a first type according to the above first or second alternative. Optional, one or more grow modules, of a second type, according to the above second alternative, may be provided, in addition. Additionally or alternatively, also other types of grow modules may be present.

[0026] According to a further alternative, which does not necessarily comprise all features of claim 1, all guide elements may be directly (preferably independently) mounted (attached) to at least one tank wall. In this case, for example, the tank wall may comprise insertion grooves into which side edges (rims, flanges) (in the second direction) of the guide elements may be inserted. The guide elements may be mounted separately in and / or on a wall of the tank. Also, interconnected guide elements (directly or via support structure) may be mounted or connected to tank walls, e.g., in insertion grooves provided in the tank walls.

[0027] According to a further preferred alternative, only one or a subset of the guide elements of a grow module may be mounted (attached) to a tank wall (directly or via a supporting means) and the other guide elements of the same grow module may be mounted within the tank via the guide elements mounted to the tank wall. The above-described structure of at least three guide elements within a grow module enables at least two flow chambers to be defined using only three guide elements in a compact and simple manner because the second guide element is used to partially define both flow chambers. Moreover, the structure enables the guide elements to be easily removed for cleaning of the surfaces defining the respective flow chambers and for cleaning the inside (wall) surfaces of the tank. Also, the structureenables an easy re-mounting of the grow modules by re-mounting the guide elements to each other or to the support structure after cleaning. Also, the structure enables an easy remounting of the grow modules in the tank.

[0028] A bioreactor according to a preferred embodiment is preferably a photobioreactor in which a liquid growth medium may be irradiated (illuminated) with light in order to cultivate photoautotrophic organisms like, for example, microalgae, cyanobacteria, macroalgae, and some mosses. In such an application of the present disclosure, walls of the tank and / or at least a part / portion of the plurality of guide elements is (are) made of a light permeable (transmissible) material such that the light can enter into the (flow) chambers through the tank walls and / or through the guide elements to grow the culture. Thus, at least portions of the walls and / or the guide elements are preferably made of transparent and / or translucent material that transmits preferably at least 50% of incident light. A preferred material at least for the guide elements or portions thereof is a transparent PP material. Alternatives are other transparent / translucent materials like e.g., glass, PVC, PET-G or PMMA etc.

[0029] Preferably, the bioreactor is an airlift photobioreactor, in which the circulation of the growth medium is achieved (preferably solely) by introducing pressurized gas into a lower portion of the growth medium held in the tank. The uprising pressurized gas results in a corresponding upflow of growth medium. Preferably, the gas is introduced into the flow chambers such that the upflow is generated within the flow chambers. Alternatively or additionally active flow machines like turbines or pumps may be used to control the flow. Alternatively or additionally, the flow may be controlled by controlling the temperature of the grow medium in specific regions of the tank.

[0030] Preferably, for each pair of adjacent (or neighboring) guide elements, between which a flow chamber is formed (defined), the guide elements are connected (to each other) by a spacer means (spacer), the spacer means being provided between the guide elements and providing (defining) the first distance. The spacer means may be formed by / as one or more side connection walls extending at least partly from the bottom to the top (in the vertical direction) of the guide elements (on each of the plates of the guide elements).

[0031] Preferably, two side connection walls are provided on each guide element and respectively extend adjacent to or on the lateral edges (rims) of the guide element(s). In this case, the (each) flow chamber may be additionally (partially) defined in the second (lateral) direction by the side connection walls.

[0032] The connection side walls are preferably integrally formed with the guide elements by performing a thermoforming process. Preferably each guide element comprises two connection side walls on the respective longitudinal side(s) that face (oppose) another (an adjacent) guide element. Preferably, the connection side walls of two guide elements, which together form (define) a flow chamber between them, are formed such that tip ends of opposing connection side walls contact each other when the guide elements are mounted in the tank. Preferably, the connection may be sealed by a sealant or adhesive. Alternatively, they are simply in contact with each other (without adhesive or sealant). In a further alternative, a sealing may be provided with or by an elastic clip connection between the connection side walls. Preferably the connection is detachable (preferably without destroying or damaging one of the connection side walls and / or the sealing) to facilitate separation of the guide elements for cleaning and maintenance purposes.

[0033] Each connection side wall has preferably a first height in the first direction which is preferably 50% or more of the first distance (gap) between adjacent guide elements in the first direction. Preferably, the first height of the connection side walls in the first direction is shorter than a second height of the protrusion portions protruding from the same plate in the first direction. Preferably, the first distance or the sum of the first heights of two opposing connection side walls contacting each other is larger than the second height of the protrusion portions defining the same flow chamber. The connection side walls of adjacent guide elements may have different heights. In this case, the heights are adapted to each other.

[0034] The connection side walls, preferably each, define a hollow portion (channel) such that a connection side wall cavity is formed therein. The connection side wall cavities may be used as a cooling channel (e.g., for flowing a coolant therethrough), a wire channel and / or channel for housing a light emitting means. The connection side wall cavities preferably extend in the vertical direction.

[0035] Alternatively, or additionally, the spacer means may be formed at any position and in any shape between two adjacent guide elements. The spacer means may be integrally formed with or on only one or both of the guide elements. Alternatively, the spacer means may be a separate structure that is attached to the guide element.

[0036] The guide elements form (define) the flow path within the (each) flow chamber. The flow path includes a vertical extension between a bottom or lower end (e.g., entry) and a top (upper) end (e.g., exit, or vice versa, depending on the flow direction). The guide elements arepreferably formed such that the vertical extension (i.e., the distance between the bottom end and the top (upper) end in the vertical direction) of the defined flow path is shorter than the (minimum, straightest) fluid travel distance through (along) the flow path. Accordingly, the guide elements are preferably formed such that the flow path does not run (extend) straight (directly) between a bottom end and a top (upper) end, but rather in an undulating manner as will be further described below. Preferably, adjacent guide elements forming a flow chamber are formed and arranged such that they overlap with each other if seen in the vertical direction Y. Thus, it is preferably not possible to see through the respective flow path / channel from the bottom end to the top (upper) end. Flow path may not be limited to the state were actually a flow of a medium is flown through but should preferably / alternatively encompass the shortest way from entry to exit.

[0037] According to a preferred embodiment (claim 2), the grow modules, in particular, the guide elements are shaped such that the flow paths, defined by the flow chambers, extend generally in a flow direction (which is in the mounted state of the guide elements and the grow modules preferably the vertical direction, also denoted as third direction).

[0038] Preferably, adjacent guide elements are formed and arranged such that the flow chamber defined between the pair of guide elements has, in a cross-sectional view perpendicular to the second direction, which is perpendicular to the first (stacking) direction and to the vertical direction (cross-sectional view in a plane spanned by the first direction and the vertical direction of the corresponding grow module), a waveform shape, a meandering shape, a zigzag shape, an undulating shape, or a sinusoidal shape. The (each) corresponding flow path extends, in an alternating manner or in sections, both in the vertical direction and also (inclined) in (towards) the first direction and has preferably also a waveform shape, a meandering shape, a zigzag shape, an undulating shape, or a sinusoidal shape. However, the present disclosure is not limited to these shapes and also encompasses shapes in which the vertical extension of the flow path is shorter than the fluid flow path, as will be further discussed below.

[0039] The shape of the flow chamber respective flow path is preferably achieved by the design of the guide elements or any additional elements (flow control elements) provided within the flow chambers. In a preferred embodiment, the guide elements are preferably formed in a generally flat plate-shape extending in a plane, which is preferably spanned (defined) by (or contains) the vertical direction and the second direction, which isperpendicular to the vertical direction. For example, one or more of the guide elements may be formed of a generally flat panel. In order to define the shape of the flow chamber / path, protrusions or guide elements are provided resulting in the desired shape. The protrusions or guide elements may be formed as an integral part of the guide elements. Alternatively, protrusions or guide elements are mounted to the guide elements or at least within the flow chamber.

[0040] In an alternative embodiment (not shown in the drawings), the guide elements itself may have a shape corresponding to the desired shape of the chamber / path. For example, the guide element may have a waveform shape, a meandering shape, a zigzag shape, an undulating shape, or a sinusoidal shape extending in the vertical direction. Such guide elements preferably extend generally along (in the direction of) a plane, which is preferably spanned (defined) by (or contains) the vertical direction and the second direction. Such guide elements extend preferably perpendicular to a plane spanned (defined) by (or containing) the vertical direction and the first direction, which is perpendicular to the vertical and the second directions. Thus, such elements generally extend in the second direction, whereas the special shape (waveform shape, a meandering shape, a zigzag shape, an undulating shape, or a sinusoidal shape) is formed by the fact that the guide elements do not extend straight in the vertical directions but rather extend with alternating inclinations or curvature along the vertical direction and partly in the first direction.

[0041] The preferred flow path (shortest vertical way through a flow chamber) is, in a generic formulation, thus, longer than a straight flow path. Furthermore, preferably turbulences are created in the flow (growth) medium such that a good mixing (agitation) of the growth medium can be achieved as the growth medium is moved along the flow path.

[0042] Alternatively, or additionally, means for hindering (obstructing) a straight flow path such as e.g., flow barriers, may be provided within the flow chambers, which flow barriers create turbulences (but not necessarily a waveform shaped flow path). In such a case, it may also be possible that the guide elements form a generally straight flow path comprising the flow barriers. The flow barriers may be formed integrally with one or both of the guide elements forming the chamber or as separate elements. The flow barriers may also function as a spacer means.

[0043] By providing a flow path with a certain shape or by providing additional means, the flow path may be extended for increasing a grow area and / or for ensuring a high grade of mixing of the grow medium.

[0044] The plurality of grow modules of the bioreactor are preferably provided at least in one horizontal level (in one horizontally extending plane). According to a preferred embodiment (claim 3), the grow modules in one level are arranged in one or several (=at least one) rows (and corresponding lines). Alternatively or additionally, the grow modules are arranged in a plurality of horizontal levels (horizontally extending planes). In this case, the bioreactor may consist of a single stack of at least two grow modules. Alternatively, each level comprises at least one row of grow modules on top of which another row of grow modules is provided. The lowermost level is preferably formed by arranging the grow modules of this level on the bottom (wall) of the tank. The bottom wall and / or the side walls of the tank preferably comprise corresponding means for defining a position of at least one or some of the grow modules or for holding them in a pre-defined position.

[0045] In case the grow modules are provided in several levels, a corresponding support structure for supporting the grow modules in different levels is preferably provided and / or the grow modules are preferably formed such that they can be stacked on each other. In the latter case, the guide elements or the support structure of the grow modules comprise corresponding structural means like engagement portions to allow the stacking or supporting on each other.

[0046] In case of several levels of grow modules, the grow modules of different levels may be arranged with the same orientation of the guide elements or with an orientation rotated by e.g., 90, 180 or 270 degrees or by any other value in between. Providing the guide elements in several levels allow bioreactors with high capacity but with a small size of base area (size of bottom surface). Furthermore, the pressurized gas is used more efficiently because the gas supplied for the lowest level can be further used for the levels above. Further, the rotated arrangement allows to avoid dead spaces with low flow.

[0047] According to another preferred aspect (claim 4), first, second and third guide elements of a grow module can be separated or moved with respect to each other such that the surfaces defining the flow chambers are exposed or are easier to reach by a corresponding cleaning tool as e.g., a brush and / or a vapor / steam or high-pressure cleaner. Preferably, the required demounting is easy and fast (supported by e.g., quick lock mechanisms, snap-fit, screws, hinges etc) and allows an easy and fast re-mount of the elements. By moving the guideelements with respect to each other, it is possible to at least partly expose the surfaces of the guide elements defining the flow chambers and / or to increase the distance between the adjacent guide elements. Both allow easier cleaning of the guide elements, in particular of the surfaces defining the flow chambers.

[0048] According to a preferred embodiment (claim 5), each of the grow modules within the bioreactor comprises at least one light emitting means (light source). These light emitting means are strategically positioned to irradiate the growth medium as it flows through the flow chambers defined by the guide elements. Additionally, a light emitting means cooling device may be provided to cool the light emitting means. The light emitting means and / or the cooling device are preferably provided within the guide elements and / or on the surface of the guide elements. Alternatively or additionally, they may be provided on the support structure. Alternatively or additionally, one or more sensors preferably for measuring one of the photosynthesis-relevant factors are provided in at least one of the grow modules. The sensors may be provided on / in the guide elements or on / in the support structure. Preferably the sensor is provided within the flow channel in order to measure the parameters of the growth medium within the flow chamber.

[0049] Providing, preferably integrated, light emitting means enhances the efficiency of the (photobioreactor) by providing controlled and localized illumination of the grow culture. This ensures that the organisms receive adequate light for photosynthesis, promoting optimal growth and productivity. The optional light emitting means cooling device may ensure that the light emitting means does not overheat. The optional sensors allow for precise measurement of parameters within the grow module to adjust / control the parameters to the optimal range.

[0050] The light emitting means are preferably light-emitting diodes (LEDs) or other suitable lighting technologies such as fluorescent lamps, halogen lamps, or metal halide lamps. The light emitting means may arranged to provide uniform or gradient illumination. The light emitting means can emit light of a specific wavelength or a broad spectrum of wavelengths tailored to the photosynthetic requirements of the cultivated organisms. The cooling element may be a passive heat sink made of a thermally conductive material, an active cooling system like a fan or a thermoelement, or a liquid cooling system that circulates a coolant through channels in thermal connection with the light emitting means. The sensor may measure parameters such as temperature, light intensity, pH, dissolved oxygen, or nutrient levels,providing valuable data for optimizing the growth conditions within the bioreactor but is not limited thereto. The sensor can be connected to a control system that automatically adjusts the light intensity, temperature, gas supply or other parameters based on the sensor readings. The light emitting means can be replaceable in case of defects.

[0051] According to a preferred embodiment (claim 6), at least a subset of the grow modules of the bioreactor comprises a grow module pressurized gas introduction means (gas injector, gas injection means) provided in the lower portion of the flow chambers. The grow module pressurized gas introduction means is configured to introduce gas into the flow chambers wherein the gas preferably rises upwardly. Alternatively or additionally, a tank pressurized gas introduction means is provided in a bottom portion of the tank below the plurality of first grow modules, the tank pressurized gas introduction means being configured to inject pressurized gas such that the injected pressurized gas is moving upward into the flow chambers.

[0052] The preferred inclusion of any one of the pressurized gas introduction means (gas injectors) facilitates the circulation and mixing of the growth medium within the bioreactor. In particular, the bioreactor is formed (configured) such that the gas passing from the introduction means rises (vertically flows) into preferably all of the flow chambers such that an upflow (lifting, vertically upward movement) of the growth medium is created (induced) by the gas (i.e., owing to the upward displacement (flow) of the growth medium caused (brought about, induced) by the upwardly rising gas bubbles).

[0053] The pressurized gas introduction means preferably injects CO2 or a mixture of gases including CO2. The pressurized gas introduction means may comprise, for example, a nozzle, a diffuser, a porous membrane, a sparger or a perforated pipe, profile or tube. Preferably, the nozzle, a diffuser, a porous membrane, a sparger is preferably removably inserted into a membrane support opening in the corresponding wall or the at least one opening is formed in an insert which is removably inserted into an insert opening in the corresponding wall, the at least one opening being preferably defined as a plurality of micro holes extending through the insert.

[0054] The pressurized gas introduction means may be connected to a gas supply via a valve and a flow controller and a corresponding tube or pipe. The gas introduction can be controlled based on the readings of sensors.

[0055] According to a preferred embodiment (claim 7), the second subset of the grow modules is arranged on top of or above at least the first subset of the grow modules. Preferably all of the grow modules of the second subset are not equipped with a pressurized gas introduction means. Besides this difference, the grow modules of the second subset preferably are similar to or have the same structure as the grow modules of the first subset. Preferably, the first and second subset further distinguish from each other by means of fixing our mounting the second subset on the first subset.

[0056] The grow modules of the first and second subsets are preferably at least partially immersed in the grow medium. The different subsets of grow modules are preferably aligned to each other in such a way that the gas (bubbles) raising from the first subset of grow modules further raises through the flow channels of the grow modules of the second subset. Thus, only the first subset of grow modules (lowest level) needs to be provided with a pressurized gas introduction means / injector allowing to efficiently use the pressurized air and to reduce the number of components in the different modules in the level above the lowest.

[0057] The grow modules of the first subset may be directly mounted on the bottom wall of the tank or be spaced apart the bottom wall by a distance. The grow modules of the second subset may be stacked directly on top of the first subset or be spaced apart by any kind of support structure.

[0058] In this respect, grow modules have been developed which, at least in operation, i.e. when gas is supplied in the flow chamber, generally float up (do not sink to the bottom wall). This depends on the amount of gas within the grow module and / or on the weight of the grow module. Correspondingly, mounting the grow modules may require a force pressing the grow modules down into the water. Such a force may be applied by a corresponding support structure or fixation structure.

[0059] The preferred inclusion of a power supply, a data processing device, a pressurized gas supply, and a light emitting means cooling supply (according to claim 8) allows for a complete and self-contained bioreactor system. The use of preferred plug-and-play connectors simplifies the installation, maintenance, and replacement of components. In particular, plug- and-play connectors for the supply of each grow module allow easy removal and maintenance of each grow module. Furthermore, additional or alternative plug-and-play connectors for the supply of each guide element allow easy removal and maintenance of each guide element.

[0060] The power supply provides electrical energy to the various components of the bioreactor, such as the light emitting means, sensors, and control system. The power supply may be without limitation a DC power supply, an AC -DC converter, a battery, or any other suitable source of electrical energy. In embodiments where light is supplied via optical fibers, the power supply provides energy to a light source external to the tank. The data processing device controls various parameters of the bioreactor, such as temperature, pH, and gas flow, and can be implemented without limitation using a microcontroller, a programmable logic controller (PLC), a general-purpose computer, or a cloud-based control system. The pressurized gas supply provides a source of carbon dioxide (CO2) or other gases or gas mictures necessary for the growth of the organisms in the culture medium and may comprise without limitation e.g. a gas cylinder, a compressor, a membrane-based gas generator, or any other suitable source of compressed gas. The light emitting means cooling supply removes heat generated by the light emitting means and may comprise without limitation a coolant medium supply with a heat pump, a Peltier element, a forced-air cooling system, or any other suitable heat dissipation mechanism. The plug-and-play connectors facilitate easy connection and disconnection of the various components and may be without limitation electrical connectors, pneumatic connectors, fluid connectors, or optical connectors. In a preferred embodiment, the light emitting means are cooled using a closed-loop liquid cooling system with a Peltier element for precise temperature controlAccording to a preferred embodiment (claim 9), the first to third guide elements (of each of the grow modules) respectively defining at least one flow chamber comprise protrusion portions (which may also be referred to as flow barriers, baffles, peaks, ridges, flanges, fins, substantially triangular arches having concave sides, etc.) which protrude into the flow chamber(s) defined by the respective guide elements. Furthermore, the protrusion portions of the guide elements are provided such that the protrusion portions protruding in the same chamber are, as viewed in the vertical direction, alternately provided on the two adjacent guide elements defining the flow chamber such that the waveform shaped flow path is formed therebetween.

[0061] The protrusion portions may have any shape. Preferably the have a shape blocking (obstruct) a straight vertical flow path from the bottom to the top and vice versa. Preferably, the protrusions portions are wall portions protruding in the longitudinal direction and extending in the second (lateral) direction, preferably, across the entire width of the flow chamber (or guide element) in the second direction. Preferably, the protrusion portions extend laterally between the two connection side walls. Preferably, except for the protrusion portions,the remainder of each guide element is a generally flat (planar) panel extending along the vertical and the second directions.

[0062] The second height of the protrusion portions in the first direction is preferably more than 50%, e.g., more than 80%, or e.g., more than 90% of the above first distance (gap) between the guide elements in the first direction. Alternatively, the sum of the second heights in the first direction of two adjacent (adjacent in the vertical direction) protrusion portions of different guide elements provided in the same flow channel is preferably more than 50%, e.g., more than 80%, or e.g., more than 90% of the above first distance (gap) between the guide elements in the first direction. The protrusion portions of adjacent guide elements protruding into the same flow chamber overlap each other at least partly as viewed in the vertical direction.

[0063] In addition to the extended length of the flow path, which enables an extended time for dissolving (absorbing) gaseous CO2 into the liquid growth medium (degree of utilization) and light irradiation, the protrusion portions also create turbulences in the flow of growth medium such that the growth medium is well mixed when flowing along the flow path.

[0064] According to another preferred embodiment (claim 10), each of the guide elements is made of (constituted by) a first plate and a second plate. The first and the second plates are arranged such that planar portions (also denoted as connection portions) thereof are parallel to each other (the protrusion portions are not parallel) and attached (affixed) to each other preferably in (along) a common contact plane (which is preferably spanned (defined) by (or contains) the lateral and the vertical directions). The first and the second plate are preferably fixedly attached to each other, for example, by plastic welding or by an adhesive.

[0065] One (preferably first and last guide element) or both (preferably second or intermediate guide elements) of the plates comprise(s) the protrusion portions which are preferably formed by thermoforming. The plates having one or more protrusion portions may also be denoted as a half-shell.

[0066] One or both of the plates comprise(s) the connection side walls (or other type of spacer means).

[0067] The thermoformed protrusion portions are preferably generally V-shaped with the bottom tip of the V protruding into the flow chamber (or towards the other guide element defining the same flow chamber). Preferably, flat (straight, planar) connection portions areformed or disposed between the thermoformed protrusion portions. Preferably, the two ends opposite the bottom tip of the V form the transitions to the flat connection portions.

[0068] Preferably, each of the protrusion portions defines a (hollow) protrusion portion cavity which preferably extends in the second direction throughout (along) the (entire) respective guide element. Preferably, the (each) protrusion portion cavity is closed by the other plate, which does not form (have) the corresponding protrusion portion.

[0069] If protrusion portions are formed on both sides of the guide element, the first plate and the second plate, which together form (constitute) the guide element, are preferably formed symmetrically with respect to a symmetry plane defined by the contact plane of the first plate and the second plate. Accordingly, the first plate and the second plate (forming two half shells) are preferably provided mirror-inverted on each other. In this case, the protrusion portions are provided at the same location in the vertical direction such that opposing protrusion portion cavities overlap to provide a common protrusion portion cavity. Preferably but not limited thereto, the symmetry is also present with respect to the connection side walls.

[0070] In an alternative embodiment, at least one of the guide elements is formed by only a single plate. In this case, the single plate may comprise the protrusion portions on one side or on both sides. Also in this case, the protrusion portions may be formed by thermoforming. The protrusion portions may form (on the other side in the first direction) open grooves. The open grooves may be closed by additional means (structure or component such as a plastic strip) to form a protrusion portion cavity, if desired.

[0071] In a preferred embodiment, adjacent flow chambers are formed such that the adjacent flow chambers are symmetrical to each other with a symmetry line within (inside) the (intermediate) guide element. Alternatively, the guide elements are formed such that adjacent flow chambers have the identical design. In this case, cross-sectional views perpendicular to the second direction of the adjacent chambers are basically identical and not mirror-inverted.

[0072] According to a preferred embodiment (claim 11), the plurality of guide elements comprises more than the above-mentioned first, second, and third guide elements. This means, the grow modules may comprise in the first direction (array / stack direction), for example, a first guide element (preferably corresponding to the above first guide element), a plurality of intermediate guide elements (preferably corresponding to the above second and third guide elements), and a last guide element, which include the above first, second, andthird guide elements. The last guide element preferably corresponds (is designed the same or similarly) to the first guide element with the difference that the protrusion portions are formed on the opposite side in the first direction. Preferably, at least ten guide elements are provided in each grow module, more preferably between 10 and 100, more preferably between 15 and 50, and more preferably between 20 and 40 such as, for example, 25, 30, or 35.

[0073] In this case, one flow chamber (defining one flow path) is preferably formed between each pair of longitudinally adjacent guide elements. For example, in case the first guide element, N intermediate guide elements, and the last guide element are provided, N+l flow chambers defining respective flow paths are preferably formed. Furthermore, in this case, each of the intermediate guide elements comprises protrusion portions on each (both) of its sides as was described above with respect to the second guide element. Of course, also in this case each of the guide elements is adapted (configured) to be mounted in the tank such that they are completely or partly immersed in the growth medium in the tank when the tank is filled with the growth medium to a predefined fill level. This includes designs in which some of the guide elements are completely immersed and some of the guide elements are partially immersed.

[0074] Thus, a simple and modular system for forming a compact bioreactor is provided.

[0075] Of course, the present disclosure is not limited to such a design. Instead, if desired, it is also possible to omit some or all of the protrusion portions on some of the guide elements such that a straight flow path is formed in one or more flow chambers between the adjacent guide elements. Also, other designs are possible.

[0076] Furthermore, it is noted that the so-called first guide element and last guide element may form the actual first and last guide elements of a guide the bioreactor but may alternatively form the first and last guide elements of a sub-portion (subset) of guide elements within the bioreactor. In other words, the plurality of guide elements as recited in the claims does not exclude that there are further guide elements or group of guide elements.

[0077] According to a preferred embodiment (claim 12), e.g., waveform shaped, meander shaped or zigzag shaped, undulating shaped or sinusoidal shaped flow paths are respectively formed between each pair of adjacent guide elements, preferably of at least a sub-portion (subset) of the guide elements. Thus, a compact bioreactor with a high number of elongated flow paths is created in a simple and modular manner.

[0078] It should be noted that bioreactors in which only some (at least two) flow paths are formed in a waveform shape (or any other of the above- or below-mentioned shapes) are also encompassed by the present disclosure.

[0079] According to a preferred embodiment (claim 13), the light emitting means and / or the light emitting means cooling device for growing (providing light to) the culture and / or the corresponding light emitting means cooling device are provided within or on one or more of the guide elements. The light emitting means and / or the light emitting means cooling device are preferably provided within (inside) the protrusion portions. Preferably, they are provided inside protrusion portion cavity(ies), preferably present in the protrusion portions.Alternatively, the light emitting means and / or the light emitting means cooling device may be designed to be resistant to (impermeable to and / or compatible with) the growth medium and may be provided on the surface(s) of the guide elements that is (are) disposed within the flow chambers (i.e., so that the growth medium contacts the guide elements). By providing the light emitting means on or in, preferably inside the protrusion portion cavity(ies), they can be easily mounted, cleaned, adjusted, and replaced and provide a high irradiation (illumination) output.

[0080] In another advantageous embodiment (claim 14), the bioreactor is further equipped with a heat exchanger (for example heat sink) and, preferably, a thermal energy source for controlling the temperature of the growth medium. The heat exchanger is preferably a member or element or portion strategically positioned either at or on a lower region of at least one of the tank side walls, or alternatively, nestled or provided between adjacent first grow modules or rows thereof. The heat exchanger is thermally connected to the thermal energy source, forming thereby a thermal management system.

[0081] The placement of the heat exchanger(s), e.g., heat sinks in proximity to the tank walls or between grow modules enables efficient heat extraction, mitigating temperature gradients and preventing overheating, especially in densely packed configurations. This ensures optimal conditions for the cultivated organisms, maximizing their growth rate and overall productivity.

[0082] The heat exchangers, e.g., heat sink may comprise, for example, a fin structure, a series of microchannels, or a network of interconnected heat pipes, or a pillow plate heat exchanger, all designed to maximize the surface area for heat exchange. The surface of the heat exchanger is preferably treated to enhance heat transfer, for example, by applying acoating with high thermal emissivity or by roughening the surface to increase turbulence. The heat exchanger is also designed with easy-to-clean surfaces to minimize biofilm formation and maintain optimal thermal performance over extended periods. The thermal energy source may be a recirculating chiller, a thermoelectric cooler, a conventional refrigerant device or heat pump or a connection to a building's existing cooling infrastructure. The cooling supply may be regulated based on temperature sensors placed within the growth medium, providing feedback for a closed-loop control system that maintains a stable and optimal temperature.

[0083] As used herein, the term 'thermal energy source' preferably refers to any device or system capable of providing thermal energy (either heating or cooling) to the heat exchangers. Non-limiting examples of suitable thermal energy sources include heat pumps, thermoelectric elements (Peltier coolers), resistive heaters, and fluid-based heating / cooling systems. In one embodiment, the thermal energy source is a heat pump that transfers heat to the heat exchanger, providing cooling to the growth medium. In another embodiment, the thermal energy source is a thermoelectric element that generates a temperature differential across its surfaces, with the cold side in thermal contact with the heat exchanger to cool the growth medium.

[0084] In a further preferred embodiment (claim 15), at least one of, preferably all of, the inside surfaces of the tank walls, the outer surfaces of the grow modules, and the outer surfaces of the heat exchanger are treated with a specialized coating. This coating is preferably an antifouling, anti-sticking, luminous, and / or luminescent coating.

[0085] Applying such a coating minimizes the formation of biofilms and the adherence of other unwanted materials to the surfaces within the bioreactor. This reduces the frequency of cleaning cycles, lowers maintenance costs, and prevents contamination that could compromise the growth of the desired organisms. A luminous or luminescent coating could help with monitoring the culture or provide additional light to the culture.

[0086] The coating may comprise a biocompatible polymer, a fluoropolymer, or a nanostructured material or silicone-based coating. The coating may be applied using techniques such as chemical vapor deposition, plasma deposition, or spray coating. The antifouling properties may be achieved by incorporating biocides or by creating a surface with a specific texture or charge that inhibits microbial attachment. The anti-sticking properties may be achieved by reducing the surface energy, preventing adhesion of organic molecules and debris (silicone). The luminous or luminescent properties may be achieved through the inclusion ofphosphorescent materials or bioluminescent compounds. The specific choice of coating material and application method is tailored to the specific organisms being cultivated and the operating conditions of the bioreactor to ensure long-term effectiveness and biocompatibility.

[0087] According to another aspect of the present disclosure, a preferred method for cleaning of the bioreactor is disclosed. By applying the sequence of firstly removing the mounted guide elements (=grow modules) and then separating / de-mounting the guide elements, an efficient cleaning method is given (claim 16). The separation (separating step) is preferably insofar the guide elements are opened (separated) in whole or in part or their distance is widened to each other or a (hinged) fold is opened to facilitate accessibility or improve cleanability of the removed grow module.

[0088] Additional aspects of the present disclosure include, but are not limited to:

[0089] According to a preferred embodiment, a pressurized gas chamber is provided / formed in or below the tank. Preferably, a bottom wall of the pressurized gas chamber is formed (defined) by the bottom wall of the tank. The pressurized gas chamber is, at least on the lower side, preferably partially defined (bounded) by and integrally formed with the bottom wall of the tank. An upper wall of the pressurized gas chamber may be flat, wave shaped, angled or curved. The side walls (in the lateral and longitudinal directions) of the pressurized gas chamber are, where possible, preferably formed integrally with the corresponding side walls of the tank. Alternatively, additional pressurized gas chamber side walls may be provided within the tank. The pressurized gas chamber is supplied with pressurized gas from a pressurized gas source, such as a gas cylinder or a gas source connected to a pump. The pressurized gas may be (e.g., pure) CO2 or a gas mixture containing CO2.

[0090] The passage (movement) of gas from the pressurized gas chamber into the interior volume tank is preferably enabled by a membrane or a plurality of micro-openings (e.g., a perforated plate) provided in and / or on the upper wall of pressurized gas chamber. The bioreactor is formed (configured) such that the gas passing from the pressurized gas chamber into the tank rises (vertically flows) into preferably all of the upflow chambers such that an upflow (lifting, vertically upward movement) of the growth medium is created (induced) by the pressurized gas (i.e., owing to the upward displacement (flow) of the growth medium caused (brought about, induced) by the upwardly rising gas bubbles).

[0091] The tank may alternatively be denoted as basin made of, for example, metal or concrete. The tank (basin) may be open (no lid) or closed by a lid. Preferably, the tank is closed, preferably by a cover or lid. The preferred lid or cover may be, for example, a flexible cover like a tarpaulin, foil, hinged plates, or a fixed cover like a plate or roof. In a preferred embodiment, the cover includes cover segments, each cover segment covering at least one grow module. Each cover may be openable separately. In this case, only the portion of the cover where a grow module is lifted out of the tank is opened.

[0092] Preferably, the guide element supporting structure includes at least one bar for supporting the guide elements thereon. Preferably, the guide elements are hung on or otherwise affixed to or held by or on the bar.

[0093] Preferably, the bar comprises corresponding notches or grooves by which each or at least the first and / or the last of the plurality of guide elements is removably fixed in (at) a predetermined position on the bars. Preferably, the first and last guide elements are fixed such that all guide elements of a grow modules are pressed on each other in the first direction. Preferably thereby the flow chambers are defined. Optionally, the guide elements are fixed on (to) the bars by additional fixing elements, such as, e.g., hooks, latches, screws, adhesive, magnets, etc. Such a structure enables the guide elements to be easily removed from the tank with the support structure and then removed (separated) from the support structure (bars) and from each other to facilitate cleaning of the tank and the individual guide elements.

[0094] According to a preferred embodiment, the bioreactor further comprises a downpipe (downcomer tube, downspout, return pipe) fluidly connecting an upper volume of the tank with a lower volume of the tank, wherein an upper portion of the downpipe is connected to the tank at a location that is displaced in the first direction and / or in a (the) second direction from a connection of a lower portion of the downpipe to the tank. The downpipe preferably fluidly connects an upper portion (volume) of the tank with a lower portion (volume) but at different locations with respect to the first direction and / or the second direction such that a further mixing of the growth medium is achieved.

[0095] According to a preferred embodiment, a foam and gas discharge means is provided in an upper wall of the tank or in an upper portion of a side wall above the growth medium level to enable foam to be separated and discharged and to collect superfluous (overflow) pressurized gas. The space (volume) in the tank above the growth medium level is preferably kept at a pressure of 0.5 to 1.5 bar in order to reduce foaming.

[0096] The tank is preferably made of materials that are durable with respect to pressure, light and growth medium. Preferably, metal, preferably stainless steel, or resin or polymer (PE) or mineral materials as concrete or glass materials, or alternative hybrid materials as reinforced materials may be used.

[0097] The support structure is preferably made of resin or polymer material or metal material or hybrid material.

[0098] The guide elements are preferably made of e.g., polypropylene or one or more other shapeable polymer materials, which are durable with respect to pressure, light and growth medium and which have suitable light transmissivity to permit light from the artificial light source(s) to transmit therethrough.

[0099] Preferably, the guide elements, in particular the protrusions, are made by thermoforming (i.e., heating the material (here, preferably a polymer), and then pressing / stamping it between one or two dies of a molding die). However, other manufacturing methods may also be utilized, such as casting or injection molding.

[0100] The tank preferably comprises a discharge opening. Furthermore, preferably hot steam for cleaning may be introduced via the pressurized gas chamber into the tank or via a separate steam introduction opening. In particular hot steam cleaning is preferably performed after the grow modules with the guide elements are reinstalled in the tank. In this case, the hot steam cleaning can be used for sterilization of the bioreactor for the next production cycle.Preferably sterilization is performed with hot steam at about 121 degrees Celsius and a pressure of 2 bar for 15 minutes.

[0101] In order to control the operation, the bioreactor further preferably comprises measuring devices for measuring pH, temperature and density of the growth medium, and electronic control devices (e.g., a computer) for controlling the temperature and supply of pressurized gas. Additional peripheral devices are a compressor, a blower (fan) for cooling, different tanks, and a hot steam generator.

[0102] For increased versatility, the bioreactor may be designed to allow for the addition or removal of grow modules based on production demands. This flexibility supports varying batch sizes and cultivation cycles, making the bioreactor suitable for both small-scale research and large-scale production environments.

[0103] Furthermore, the bioreactor can be equipped with a centralized control interface accessible remotely, allowing for real-time adjustments and monitoring, thereby increasing efficiency and reducing manual intervention.

[0104] According to a preferred embodiment (not reflected in the claims), at least two of the flow chambers of a grow module are upflow chambers which are adapted to guide an upflow of the growth medium, for example caused by the gas bubbles. The volume flow flowing upwards must be balanced by a volume flow flowing downwards. Accordingly, at least one downflow region (or chamber) adapted to guide a downflow of the growth medium is defined within the tank. Preferably, a downflow region is formed between at least one grow module and an inside surface of a side wall of the tank, or is formed by at least one of the flow chambers of one grow module, or is defined between two outer guide elements (outer guide element is preferably a first or a last guide element) of two adjacent grow modules (adjacent grow modules with same orientation), or is defined between side connection walls of adjacent grow elements (adjacent grow modules with same orientation), or is defined between side connection walls and an outer guide element of an adjacent grow module (adjacent grow modules rotated by 90 degree).

[0105] Preferably, an upper end portion and a lower end portion of each of the upflow chambers are fluidly connected with the interior volume of the tank, and preferably upper end portions of the upflow chambers are in fluid communication with the at least one downflow chamber. Further, the at least one downflow chamber is preferably in fluid communication with lower end portions of the upflow chambers to circulate the growth medium within the tank from the upper end portions of the upflow chambers to the lower end portions of the upflow chambers via the at least one downflow chamber and from the lower end portions of the upflow chambers to the upper end portions of the upflow chambers via the upflow chambers. In case of grow modules arranged on top of each other, the upflow chambers and / or downflow chambers of these grow modules are arranged also on top of each other such they extend through all of the grow modules arranged on top of each other.

[0106] According to a preferred embodiment, the heat exchangers (heat sinks) are provided in or on side walls of the tank that define downflow chambers. Preferably, heat exchangers are provided in, on or at the lower regions of corresponding downflow chambers. By cooling a downflow chamber in or at a lower region of a downflow chamber, the downflow (downward flow) of growth medium is further accelerated due to the temperature drop, which provides(results in) an improved circulation flow through the bioreactor. Furthermore, the temperature of the growth medium, which is caused to rise due to the irradiation with light and / or by the cultivation process, can be controlled (regulated).

[0107] According to another aspect of the disclosure, a grow module (also sub-unit or subsystem or component or group of guide elements) for use in a bioreactor is provided, the grow module comprising at least a first guide element, a second guide element, a third guide element, and preferably a guide element support structure on which the guide elements are detachably mounted.

[0108] Preferably, according to another aspect, a grow module is provided which is configured to be used in a bioreactor, the grow module comprising a first guide element, a second guide element, a third guide element, and a guide element support structure, wherein the guide elements are detachably mounted to the guide element support structure such that, in the mounted state, the first, the second, and the third guide elements are disposed next to each other to form a first flow chamber defined between the first and the second guide elements and a second flow chamber defined between the second and the third guide elements. Preferably, first and second flow paths of the growth medium in a vertical direction through the respective first and second flow chambers have a waveform shape, a meandering shape, a zigzag shape, an undulating shape or a sinusoidal shape, or first and second flow paths of the growth medium in a vertical direction through the respective first and second flow chambers have a shape other than a waveform shape, a meandering shape, a zigzag shape, an undulating shape or a sinusoidal shape.

[0109] According to another aspect, the bioreactor may also be characterized in that each of at least a first subset of the plurality of grow modules (14a) comprises a grow module pressurized gas injector (such as an opening in a pipe or in a portion of the guide element forming a pressurized gas pipe, or a membrane, or a nozzle, but not limited thereto; also denoted as introduction means in the present disclosure) provided below the flow chambers of the corresponding grow module or in a vertical lower portion of the flow chambers (26, 28, 28i) of the corresponding grow module. The grow module pressurized gas injector is preferably configured to inject pressurized gas into the flow chambers.

[0110] In addition or alternatively, at least one, preferably all, of the guide elements of at least a (the) first subset of the plurality of grow modules comprise(s) in a vertical lower portion of the guide element respective guide element pressurized gas injectors (such as an opening in apipe or in a portion of the guide element forming a pressurized gas pipe, or a membrane, or a nozzle, but not limited thereto; also denoted as introduction means in the present disclosure). The guide element pressurized gas injectors are preferably configured to inject pressurized gas into the respective flow chambers.

[0111] In addition or alternatively, the bioreactor further comprises a tank pressurized gas injector (such as an opening in a pipe or in a portion of the guide element forming a pressurized gas pipe, or a membrane, or a nozzle, but not limited thereto; also denoted as introduction means in the present disclosure) is provided in a bottom portion of the tank below the plurality of grow modules, preferably below the flow chambers of the grow modules. The tank gas injectors are preferably configured to inject pressurized gas such that the injected gas is moving upward into the flow chambers.BRIEF DESCRIPTION OF THE DRAWINGS

[0112] The invention will be described in more detail hereinafter with reference to illustrative preferred embodiments shown in the accompanying drawings, in which:Fig. 1 shows a schematic perspective view of a bioreactor according to a first embodiment;Fig. 2 shows a schematic perspective view of an exemplary grow module of the bioreactor according to Fig. 1;Fig. 3 shows a schematic perspective view of a detail of bioreactor according to a second embodiment, wherein the grow modules of the bioreactor are arranged on top of each other;Fig. 4 shows a schematic and simplified cross-sectional view perpendicular to a lateral (second) direction of a detail of a bioreactor according to a third embodiment,Fig. 5 shows a schematic and simplified cross-sectional view perpendicular to the lateral (second) direction of a first guide element of Fig. 4,Fig. 6 shows a schematic and simplified cross-sectional view perpendicular to the lateral (second) direction of a second or intermediate guide element of Fig. 4,Fig. 7 shows a schematic and simplified three-dimensional view of three of the guide elements of Fig. 4,Fig. 8 shows a schematic and simplified top view of a detail of Fig. 4, and Figs. 9 and 10 different possible patterns of grow modules in one level. 1DETAILED DESCRIPTION

[0113] Embodiments of the disclosure will be further described in the following with reference to the drawings. The drawings include an indication of a coordinate system fixed with respect to the bioreactor wherein a longitudinal direction is denoted as X, a lateral direction is denoted as Z and a vertical direction (which preferably corresponds to the gravity direction) is denoted as Y. The longitudinal direction X and the lateral direction Z are preferably perpendicular to each other and to the vertical direction Y. Thus, the longitudinal direction X and the lateral direction Z preferably span a horizontally extending plane. To simplify illustration of significant portions of the different embodiments and details thereof, the drawings are not fully consistent, e.g., not all details are present in all drawings or some details are not correctly reflected in all drawings. Thus, the bioreactor according to Fig. 4 in fact may comprises the same or similar features as the bioreactor according to Fig. 1 unless the features are explicitly described to be different. The same or similar reference signs are used for the same or similar features.

[0114] A first embodiment will be described with reference to Fig. 1 and 2. In some paragraphs, it is also referred to the other drawings to show where the corresponding features can be found with respect to other embodiments or if other embodiments show some features in more detail or in a different way which may also be applicable to the present embodiment. In Fig 1, one of the grow modules comprises different types of guide elements forming different shapes of flow chambers / paths only for facilitating the explanation of preferred designs of the flow chambers / paths. The other grow modules are more simplified and comprise only one type of guide elements. Although the disclosure is not limited thereto, in preferred embodiments of the bioreactor, the guide elements / grow modules are all of the same or similar type resulting in that the flow chambers / paths usually also have the same / identical design.

[0115] Fig. 1 shows a schematic perspective view of a bioreactor 1 (or the bioreactor system, if the bioreactor is considered to be formed by the tank and the grow modules, only) according to a first embodiment of the invention. Bioreactor 1 comprises a tank 10 filled with a growth medium 12 at least up to a certain level LI in a vertical direction Y. For example, level LI may define an operational level, which may define a volume that is at least 70%,preferably at least 80% or at least 90%, of the total volume of the interior space (volume) of the tank 10. A plurality of grow modules 14 are located within tank 10. The tank may preferably be shaped as a rectangular cuboid. In such an embodiment, tank 10 has a bottom wall 76, four side walls 68 (two lateral side walls and a front side wall and a rear side wall) and optionally an upper wall or cover (not shown). In alternative embodiments, the tank may have any other shape such as, for example, a cylindrical shape or other type of curved and / or polygonal shape.

[0116] As can be seen in Fig. 1, the grow modules 14 of the first embodiment are arranged in three rows Rl, R2, and R3 on one horizontal level (horizontal plane) within the tank 10. According to other embodiments, the grow modules 14 or the rows Rl, R2, and R3 of the grow modules are stacked or arranged on top of each other (see also Fig. 2). The number of grow modules 14 in one row determines the number of lines (here also three) perpendicular to the rows.

[0117] The bioreactor (or the bioreactor system) of this embodiment comprises a power supply 100, a data processing device 102, a pressurized gas supply 104, and a light emitting means cooling supply 106. Each grow module preferably comprises, as shown in Fig. 4, a light emitting means 74 connected with the power supply 100, and / or a sensor 74b connected with the data processing device 102, and / or a grow module pressurized gas introduction means 77a and / or a guide element pressurized gas introduction means 77b (shown in Fig. 2) connected with the pressurized gas supply 104, and / or a light emitting means cooling device 74a connected with the light emitting means cooling supply 106. The connection is preferably realized via a pipe / cable via separate or common plug-and-play connector(s) 100a. None of the means in necessarily provided.

[0118] Further, an optional tank pressurized gas introduction means 77c is provided in a bottom portion of the tank 10 below the plurality of first grow modules 14. As a further option, a grow module pressurized gas introduction means 77a (not shown in Fig. 1, potential position indicated in Fig. 2 and shown in more detail in Fig. 4) is provided. All pressurized gas introduction means may be connected to the pressurized gas supply 104.

[0119] Each grow module 14 of the exemplary embodiment of Fig. 1 comprises five guide elements 20, 22, 24, 22i, 24i supported in / at a guide element support structure 16 (see also Fig. 2). The guide element support structure 16 may be formed from bars or profiles for supporting the guide elements thereon. Preferably a support frame is formed. The guideelements are hung on or mounted or otherwise affixed to or held by support structure 16. Here, the support structure 16 comprises corresponding notches or grooves (schematically shown in the top bars) by which at least the first and / or the last of the plurality of guide elements 20 (here all) is removably fixed in (at) a predetermined position (here by corresponding hooks 25 schematically shown (see also Fig. 7). Optionally, the guide elements are fixed on (to) support structure 16 by additional fixing elements, such as, e.g., hooks, latches, screws, adhesive, magnets, etc.

[0120] The guide elements 20, 22, 24, 22i, 24i are arranged next (adjacent) to each other (one after another, e.g., in sequence or succession) in a first direction, which here corresponds to a longitudinal direction X, which is perpendicular to the vertical direction Y. Each of the guide elements is formed (shaped, configured) as a fluid guiding panel having, in this embodiment, a general plate shape. Fig. 1 shows schematically a ripped surface generally extending in a plane parallel to a plane spanned by (containing) the vertical direction Y and a second direction, which here corresponds to a lateral direction Z, which is perpendicular to the longitudinal direction X (first direction) and to the vertical direction Y. In other words, each guide element 20, 22, 24, 22i, 24i extends perpendicular or at least substantially perpendicular to the longitudinal direction X and thus preferably extends parallel to the vertical direction Y. The guide elements, despite one grow module of Fig. 1 exemplarily demonstrates different shapes of guide elements, preferably generally extend parallel to each other.

[0121] A first (fluid) flow chamber (channel, passageway) 26 is formed (defined) between the first and second guide elements 20, 22. A second (fluid) flow chamber (channel, passageway) 28 is formed (defined) between the second and third guide elements 22, 24. Thus, both flow chambers 26, 28 are defined or bounded in part by the second guide element 22. Third and fourth flow chambers 28i are formed (defined) between the third 24, 22i, fourth 22i and fifth 24i guide elements (see also Fig. 4 and corresponding description).

[0122] Here the first and second guide elements 20, 22 form an exemplary a zigzag shaped first flow chamber 28 and correspondingly shaped flow path 30, as an example. The second and third guide elements 22, 24 form an exemplary meander shaped second flow chamber 30 and correspondingly shaped flow path 32, as an example. The third and fourth guide elements 22, 22i form an exemplary waveform or sinusoidal or undulating shaped third flow chamber 28i and correspondingly shaped flow path 34, as an example. The last guide elements are only shown schematically and with no specific shape (small rips).

[0123] If at least one of the pressurized gas introduction means (e.g., injectors) 77a, 77b and / or 77c are supplied with pressured gas and, accordingly, inject / supply / introduce pressurized gas below or in a lower part of the flow chambers 26, 28, 28i, gas 84 rises into and / or within the corresponding flow chambers. Thus, gas 84 acts to uplift (upwardly push) the growth medium 12 within the flow chambers 26, 28, thereby creating (inducing) an upflow (upwardly moving current) of growth medium 12 through the flow chambers. Thus, this mechanism achieves (effects, generates) a circulating flow of the growth medium 12 upwardly through the flow chambers 26, 28. The flow chambers 26, 28 are therefore also denoted as upflow chambers. The upflow, at the same time, creates a downflow at another portion of the tank.

[0124] One or more exemplary and optional heat exchangers 110 are provided at or on a lower region of at least one of the tank side walls 68 and / or between adjacent first grow modules 14 of the plurality of first grow modules or between adjacent rows R of first grow modules of the plurality of first grow modules. Alternatively (not shown), the heat exchangers are provided in addition between the lines of grow modules.

[0125] Preferably, the heat exchangers 110 may be formed (constituted) as conventional (e.g., metallic or thermally conductive) passive heat sinks as cooling plates, fins and / or ribs, for example, formed in a tank wall. They are provided to allow a heat exchange between the inside of the tank and the outside such that growth medium (preferably downflowing growth medium) is cooled when the growth medium passes along the heat sinks 110. The heat sinks may be integrally formed with portions of the tank side wall.

[0126] Alternatively, or additionally, an active thermal energy source 108 may actively cool the heat exchangers 110 during operation of the bioreactor 1 (e.g., in response to detection of the growth medium 12 exceeding a first predetermined temperature). The heat exchangers 110 are preferably pillow plate heat exchangers. The heat exchangers 110 may also be heated by the thermal energy source 108, e.g., in response to detection of the growth medium 12 falling below a second predetermined temperature that is lower than the first predetermined temperature. In this way, the temperature of the growth medium during operation of the bioreactor 1 may be suitably regulated to maintain the temperature of the growth medium in an optimal temperature range for the organism(s) being cultivated therein.

[0127] Preferably, a foam and gas discharge means (port, discharge opening, aperture) (not shown) is provided in an upper wall or cover of the tank 10. The foam and gas dischargemeans are adapted (configured) to separate foam, which may build up due the airlift from (agitation of) the growth medium, and to discharge the foam to a not shown foam collector. Furthermore, it is adapted (configured) to collect or suck superfluous (overflow) pressurized gas which has risen (vertically passed) through the growth medium. In order to reduce foam generation, the space (gaseous volume) above the top surface of the growth medium is preferably kept at a pressure of 0.5 to 1.5 bar.

[0128] Fig. 3 shows a schematic perspective view of a detail of bioreactor 1 according to a second embodiment. The bioreactor of the second embodiment differs from the bioreactor according to the first embodiment in that the grow modules 14a, 14b, 14c of the bioreactor are arranged on top of each other, forming a vertical stack. This stacked configuration allows for a more compact use of space and / or can increase the overall capacity of the bioreactor. The grow modules may be arranged with the same orientation or with a rotated orientation relative to each other.

[0129] In the embodiment of Fig. 3, the stack consists of three grow modules 14a, 14b, 14c arranged on top of each other. The middle grow module is rotated by 90 degrees about the vertical axis with respect to the two other grow modules. In this embodiment, the first direction (stack direction) of the middle grow module 14b corresponds to the longitudinal direction X of the bioreactor, whereas the first directions of the first and third grow modules 14a and 14c corresponds to the lateral direction Z of the of the bioreactor. Generally, in case several levels of grow modules, the grow modules of different levels may be arranged with the same orientation of the guide elements or with an orientation rotated by e.g., 90, 180 or 270 degrees or any value in between. The number of levels (guide elements arranged on top of each other) is not limited, for example, 2, 3, 4, 5, 10, 15, or even more levels may be provided. Finally, the size of each module in comparison to the depth of the tank and the filling level is decisive.

[0130] In case the grow modules 14a, 14b, 14c are provided in several levels, a support structure for supporting the grow modules in different levels (not shown) may preferably be provided and / or the grow modules or their support structure may preferably be configured such that they can be stacked on each other. In the stacked case, the guide elements or the support structure of the grow modules comprise corresponding structural means like engagement portions to allow the direct stacking or direct supporting on each other.

[0131] In an embodiment with stacked grow modules (Fig. 3), it is preferred that only the grow modules 14a of the first (lowest) level (= a first subset of grow modules) are equipped with a grow module pressurized gas introduction means 77a provided below the flow chambers 26, 28 or with guide element pressurized gas introduction means 77b in a vertical lower portion of the flow chambers to inject pressurized gas into the flow chambers. The grow modules of the levels above the first level (second subset of grow modules) 14b, 14c, which are arranged on top of or above at least a part of, preferably all of the first subset of the plurality of first grow modules 14a, are not equipped with a pressurized gas introduction means. Instead, in this case, the gas (bubbles) rises from the first subset of grow modules and further rises through the flow channels 26, 28 of the grow modules 14b, 14c of the second subset.

[0132] Fig. 4 shows a schematical and simplified detail of a preferred third embodiment of a bioreactor. The bioreactor according to Fig. 4 is similar to the bioreactor according to claim 1. The bioreactor shown in Fig. 4 differs from the bioreactor of Fig. 1 particularly in that the grow modules, in particular and preferably the guide elements of the grow modules, have a preferred design as described in more detail below. The remaining features are preferably identical or similar to the bioreactor shown in Fig. 1. The tank is shown with an option cover 84.

[0133] As in Fig. 1, inside the tank 1, preferably a plurality of grow modules 14 is provided (only one is shown) in rows and lines. The grow module shown in Fig. 4, preferably all grow modules in this embodiment, comprises at least three guide elements 20, 22, 24, preferably more guide elements (a grow module with five guide elements is shown). When the tank 10 is filled with growth medium 12 up to the level LI, the guide elements 20, 22, 24, 22i, 24i are at least partially immersed, preferably nearly completely or completely immersed, in the growth medium 12. As in the first embodiment, the generally plate shaped guide elements include a first guide element 20, a second guide element 22, 22i, a third guide element 24, 22i, a fourth guide element 22i and a fifth guide element 24i arranged next (adjacent) to each other (one after another, e.g., in sequence or succession) in the first direction (here longitudinal direction X), which is perpendicular to the vertical direction Y (third direction). Each of the guide elements is formed (shaped, configured) as a fluid guiding panel having a partially flat shape (with protrusions projecting from the flat portions thereof) extending in a plane parallel to a plane spanned by (containing) the vertical direction Y and a lateral direction Z (second direction), which is perpendicular to the longitudinal direction X and to the vertical directionY. Thus, in Fig. 4 as well as in Fig. 1, the first direction corresponds to the longitudinal direction X, the second direction to the lateral direction Z and the third direction to the vertical direction Y.

[0134] As in Fig. 1, the first (fluid) flow chamber (channel, passageway) 26 is formed (defined) between the first and second guide elements 20, 22. The second (fluid) flow chamber (channel, passageway) 28 is formed (defined) between the second and third guide elements 22, 24. Thus, both flow chambers 26, 28 are defined or bounded in part by the second guide element 22. The thicknesses (widths) of the flow chambers 26, 28 in the longitudinal direction X are defined by distance dl between adjacent ones of the guide elements in the longitudinal direction X. The distance dl is preferably the sum of the first heights hl of two connection side walls contacting each other.

[0135] Within the flow chambers 26, 28, respective waveform shaped flow paths 30, 32 are defined. Herein, the shape or spatial contour of the fluid flow paths 30, 32 along the vertical direction, as defined by the guide elements 20, 22, 24, may be alternately characterized, e.g., as zigzag, undulating, wave-like (waveform shaped), oscillating or sinusoidal. The growth medium flows along the flow paths 30, 32 when the bioreactor is in operation (see also the exemplary arrows in the exemplary flow path 32i in Fig. 4).

[0136] The waveform shape of the flow paths 30, 32 is achieved by providing means (e.g., flow barriers, baffles, protrusions, etc.) for preventing, obstructing or blocking a straight (linear) flow of the guide medium 12 in the vertical direction Y. In the present embodiment, such means are or comprise protrusion portions 42, 44, 46, 48 that protrude (project) horizontally in the longitudinal direction X (as can be seen, e.g., in Figs. 4 to 8) and extend over (across) the width (preferably the entire width or at least substantially the entire width) of the respective guide element in the lateral direction Z (as can be seen, e.g., in Fig. 7).

[0137] The first guide element 20, which is shown in more detail in Fig. 5, has a plurality of protrusion portions (protrusions, baffles, peaks, ridges, flanges, fins, substantially triangular arches having concave sides) 42, three of which are shown in Figs. 4. Each protrusion portion 42 is provided on the (longitudinal direction) side of the first guide element 20 which faces the second guide element 22, so that the facing sides of the guide elements 20, 22 define the first (fluid) flow chamber 26. Accordingly, the protrusion portions 42 protrude in the longitudinal direction X (with negative sign).

[0138] The second guide element 22, which is shown in more detail in Fig. 6, has a plurality of first protrusion portions 44 and a plurality of second protrusion portions 46 on the respective sides, four of each are shown on each side in Fig. 4 (a more realistic view is shown in Fig. 6, where a plurality of protrusion portions 44 is shown). Each first protrusion portion 44 is provided on the (longitudinal direction) side of the second guide element 22 which faces the first guide element 20. Accordingly, the first protrusion portions 44 protrude in the longitudinal direction X (with positive sign).

[0139] In order to achieve the waveform shape (or e.g. the meandering shape, the undulating shape, the oscillating shape, the sinusoidal shape, or the zigzag shape or combinations thereof, the protrusion portions 42 on the first guide element 20 and the protrusion portions 44 on the second guide element 22 are, as viewed along the vertical direction Y through the flow chamber 26, alternately provided (defined) on the guide elements 20, 22, i.e. disposed at alternating positions along the vertical direction Y. Furthermore, each protrusion portion 42, 44 preferably has a second height (length) h2 in the longitudinal direction X which is more than 50% of the distance dl between the guide elements 20, 22 such that the protrusion portions overlap each other when viewed in the vertical direction (see Fig. 5). For example, the second height h2 is preferably at least 60% of the first distance dl, such as at least 70% of the first distance dl or at least 75% or at least 80% of the distance dl. Furthermore, the second height h2 is preferably less than 95% of the distance dl, such as less than 90% of the distance dl or less than 85% of the distance dl. Ranges for the second height h2 may be arbitrarily defined based on any of the preceding upper and lower limits. The second height h2 is defined as the distance (length) in the longitudinal direction X from a base portion of each protrusion portion 42, 44, 46, 48 that is colinear with the flat portions of the guide elements to the apex (peak, top, crest) of the protrusion portion 42, 44, 46, 48 in the longitudinal direction X.

[0140] The distance dl may preferably in the range of 0,5cm to 30cm, more preferably between 1cm and 20cm, even more preferably between 2cm and 10cm, for example, 3cm, 5cm or 7cm. The distance may preferably be a distance between parallel extending portions of adjacent guide elements. Preferably, the distance may be a minimum distance. Thus, there may be portions, in which the distance is larger. In order to clean the surfaces of the guide elements, the is increased in order to allow cleaning. The increase is achieved by moving adjacent guide elements with respect to each other or by separating adjacent guide elements from each other in the longitudinal direction. Alternatively, hinged guide elements may beopened (angle is changed) or adjacent guide elements may be moved in parallel to each other to expose the surfaces defining the flow chambers, insofar open in whole or in part or widen in their distance to each other or fold open by a specific mechanism to facilitate accessibility or improve cleanability.

[0141] The second (fluid) flow chamber 28 is substantially mirror-inverted to the first (fluid) flow chamber 26 with a symmetry line lying in (along, colinear with) the second guide element 22. Thus, the second guide element 22 itself has a mirror symmetrical shape with respect to the symmetry line. Accordingly, the second guide element 22 comprises the second protrusion portions 46 protruding opposite (in the longitudinal direction X) to the first protrusion portions 44 towards the third guide element 24. Furthermore, the third guide element 24 has (first) protrusion portions 48 protruding towards the second guide element 22 in a mirror-inverted way with respect to the protrusion portions 42 of the first guide element 20. In other words, the protrusion portions 42, 48 extend in a mirror-symmetric way when the vertical extension of the second guide element 22 is considered to be the symmetry line or plane for first and third guide elements 20, 24.

[0142] The third guide element 24 has, similar to the second guide element 22, protrusion portions on both sides in the longitudinal direction because another (third) flow chamber 28i is formed (defined) on the side opposite to the second guide element 22 of the third guide element 24. Guide elements, which have protrusion portions on both sides, i.e., similar to the second and third guide elements 22, 24, will also be called intermediate guide elements 22i in the description and in the claims (see also Fig. 5).

[0143] In addition to the second and third guide elements 22, 24, the bioreactor 1 shown in Fig. 4 has, in the longitudinal direction X, the fourth guide element that serves as another intermediate guide element 22i, and a fifth guide element that serves as a last (longitudinally outermost) guide element 24i of the array (stack, sequence, alignment) of guide elements. Figs. 4 to 8 show only five guide elements in an exemplary manner, whereas in practice more preferably guide elements can be used. This can also be seen from Fig. 8, wherein the two wavy lines are intended to indicate that more than the guide elements which are shown, may actually be present. Corresponding wavy lines were omitted in Fig. 4 for clarity reasons. (The wavy lines shown in Fig. 4 are intended to indicate that the guide elements 20, 22, 24, 22i may be longer, and thus have additional protrusion portions, in the vertical direction Y than is actually shown in Fig. 4.

[0144] In Fig. 4 (as in Fig. 1), an uneven number of (i.e., five) guide elements are preferably used. The last guide element 24i is provided (shaped, configured) in a mirror-inverted manner with respect to the first guide element 22. The vertical extension of the middle (here third) intermediate guide element 22i is considered to be the symmetry line for first and last guide elements 20, 24i, the protrusion portions 42 of the first and last guide elements 22, 24i extend in a mirror-symmetric way. Thus, similar to the first guide element 20, the last guide element 24i also has protrusion portions only on the side facing the adjacent intermediate element 22i.

[0145] In the third embodiment, each guide element is preferably formed of (comprises, is constituted by) two plates which are attached to each other. Preferably, the two plates are affixed to each other by an adhesive or plastic welding (fusing).

[0146] Specifically, the first guide element 20 comprises a planar (flat) first plate 50 and a second plate 52 (see also Fig. 2). The second plate 52 comprises the protrusion portions 42 and planar (flat) portions 47 respectively extending between adjacent ones of the protrusion portions 42. The planar portions 42 extend in parallel to the first plate 50 and connect the protrusion portions 42 in the vertical direction Y. The planar portions 47 flushly contact the planar first plate 50 when the two plates 50, 52 are affixed to each other.

[0147] The protrusion portions 42 are preferably formed by performing a thermoforming process such that (first type) protrusion portion cavities (hollows) 43 are created between the first plate 50 and the protrusion portions 42 of the second plate 52.

[0148] The last guide element 24i is formed in the same or similar way but in a mirror- inverted manner.

[0149] The intermediate guide elements 22i (or the second and third guide elements 22, 24) comprise a first plate 54, 58 and a second plate 56, 60, which have the respective protrusion portions 44, 46, 48 extending in opposite directions formed (defined) thereon (see also Fig. 6). Thus, a (second type) protrusion portion cavity 45 is formed between each pair of oppositely extending (projecting) first protrusion portion 44, 46 and second protrusion portion 48.

[0150] Thus, four waveform shaped fluid flow paths are formed (provided) within the flow chambers 26, 28, 28i respectively defined between each two adjacent ones of the guide elements. In the embodiments, these (fluid) flow chambers defined between the guide elements will be referred to as upflow chambers (i.e., chambers, channels or passageways, in which the growth medium is intended to flow vertically upwardly). Therefore, when thebioreactor 10 is operating, the growth medium flows upward through the upflow (rising, vertically extending) chambers 26, 28, 28i.

[0151] Because the growth medium 12 has to be circulated within the tank 10, it is necessary to provide at least one passageway for a downflow (vertically downward flow) of the growth medium. In the bioreactors of the present disclosure, downflow regions (chambers, channels, passageways) 62 for enabling the growth medium to flow downward are provided in at least one of the free spaces between adjacent grow modules (adjacent in the Z or X direction) and between grow modules and corresponding inner wall surfaces of side walls of the tank (see downward arrows in Figs. 4 and 8). In order to allow a downflow, pressurized air is normally not injected below such downflow regions 62.

[0152] Because the guide elements are completely immersed in the growth medium 12 in the embodiment shown in Fig. 4, growth medium 12 can flow from (over) open, upper end portions (edges) of the upflow chambers 26, 28, 28i to the downflow regions 62. After flowing downward through the downflow regions 62, the growth medium 12 can flow to open, lower end portions (edges) of the upflow chambers 26, 28, 28i and can then flow again upwards through the upflow chambers 26, 28, 28i.

[0153] Because the guide elements 20, 22, 24, 22i, 24i are removably provided (held or disposed) within the interior space (volume) of the tank 10, the guide elements 20, 22, 24, 22i, 24i are supported within the tank with a clearance fit or even without directly contacting any inside surface of the walls of the tank 10, as can be understood by viewing Fig. 4.

[0154] To create a well-defined and strong flow of the growth medium through the respective (fluid) flow chambers, it is preferred that the respective (fluid) flow chambers are separated (isolated, partitioned) from each other. In particular, it is preferred that the upflow chambers are separated (isolated, partitioned) from the downflow chambers except for the fluid connection of the chambers at the upper end portions and at the lower end portions to form a closed loop. Therefore, in particular there should be no direct fluid connection in regions between the upper end portions and the lower end portions of the respective (fluid) flow chambers.

[0155] The upflow chambers 26, 28, 28i are defined (bounded, circumscribed) in the longitudinal direction X by the guide elements. In order to also define (bound, circumscribe) the upflow chambers 26, 28, 28i in the lateral direction Z, the bioreactor 1 further preferablycomprises connection side walls 72 (see also Fig. 7). The connection side walls 72 are provided (disposed) between each pair of adjacent guide elements 20, 22, 22i, 24, 24i to forming a upflow chamber 26, 28, 28i at the lateral edge (rim) portions of the guide elements 20, 22, 22i, 24, 24i and have a longest extension (length) in the vertical direction Y. Preferably, the connection side walls 72 are integrally formed by thermoforming the flat plates of both of the adjacent guide elements 20, 22, 22i, 24, 24i and connect the adjacent guide elements 20, 22, 22i, 24, 24i such that the corresponding upflow chamber is defined also in the lateral direction Z.

[0156] The downflow regions 62 are, thus, formed between the connection side walls 72 and corresponding inside surfaces 66 of side walls 68 of the tank 10.

[0157] Specifically, in the present embodiment, the connection side walls 72 extend (span) a distance to the lateral edge (rim) of the corresponding guide element 20, 22, 22i, 24, 24i such that the downflow region 62 is at least partly defined also by the corresponding guide elements 20, 22, 22i, 24, 24i in the longitudinal direction X.

[0158] In particular, the connection side walls 72 are preferably formed by thermoforming the edge (rim) portion of the corresponding guide element 20, 22, 22i, 24, 24i, thereby resulting in a cross-section perpendicular to the vertical direction that is a V-shape or truncated cone shape, where the top of the shape has a greater distance to (is farther from) the edge than the base, as can be seen in Fig. 8 along the left and right sides of the bioreactor.

[0159] Furthermore, the bioreactor 1 according to the first embodiment comprises LED stripes (strips) as light emitting means 74, which are provided inside some or all (in Fig. 4 only one is shown for the sake of simplifying the illustration) of the (first and second type) protrusion portion cavities 43, 45. Preferably, the protrusion portion cavities 43, 45 are sealed (e.g., in a water-tight manner) from the surrounding environment, such that the stripes are protected (shielded, isolated) from the growth medium. Corresponding seals or gaskets (necessary seals therefore) are not shown for the sake of simplifying the illustration. Furthermore, the connection side walls 72 are preferably formed (shaped) such that a connection side wall cavity 75 (shown in a simplified manner only in Fig. 5) is provided therein. The connection side wall cavities 75 are designed and used to receive (contain, hold) in a similar way to the protrusion portion cavities additional LED stripes (strips) and / or to receive (contain, hole) one or more power cables for distributing energy (conducting current) to the light emitting means 74.

[0160] Furthermore, the bioreactor 1 according to the embodiment shown in Fig. 4 comprises grow module pressurized gas introduction means 77a and guide element pressurized gas introduction means 77b. As can be seen, the grow module pressurized gas introduction means 77a are formed as hollow profiles or tubes or pipes extending in the direction X and comprising membranes or openings through which the pressurized gas can enter the upflow chambers 26, 28, 28i. The grow module pressurized gas introduction means 77a are supplied with pressurized gas via, for example, a supply pipe provided on the guide element support structure 16 and / or formed by at least one of the bars (pipes) of which the support structure is formed. The supply pipe may be connected, for example, via a supply tube 104a and corresponding connectors with the pressurized gas supply 104 as shown in Fig. 1.

[0161] The guide element pressurized gas introduction means 77b can be realized as separate means like tubes, hollow profiles or pipes provided on lower ends of a surface 34, 36, 38, 40 of a guide element forming an upflow chamber (see Fig. 4). Alternatively or additionally, the guide element pressurized gas introduction means 77b are formed integrally with the respective guide element in a lower surface region of a surface forming an upflow chamber (see for example dashed line in Fig. 7). Also, the guide element pressurized gas introduction means 77b are supplied with pressurized gas via, for example, a supply pipe provided on the respective guide and / or formed at least partly in the respective guide (see dashed line in Fig. 7). The supply pipe may be connected, for example, via a supply tube 104a and corresponding connectors with the pressurized gas supply 104 as shown in Fig. 1.

[0162] When the gas 84 rises in the upflow chambers 26, 28, 28i, the gas 84 acts to uplift (upwardly push) the growth medium 12 within the upflow chambers 26, 28, 28i, thereby creating (inducing) an upflow (upwardly moving current) of growth medium 12 through the upflow chambers 26, 28, 28i. Thus, this mechanism achieves (effects, generates) a circulating flow of the growth medium 12 upwardly through the upflow chambers 26, 28, 28i and then downwardly through the downflow regions 62.

[0163] The gas introductions means (injectors) 77a, 77b and / or 77c preferably comprise a membrane and / or openings (preferably, micro-openings) (see Figs. 4 and 7). Preferably, micro-openings (perforations) are formed in a corresponding insert, which is preferably configured (adapted) to be removably inserted into a corresponding insert opening in the corresponding pipe, profile or tube or portion. The membrane and / or the insert are formedsuch that they can be replaced if necessary (for example, in case of corrosion, wear, breakage, etc.).

[0164] In the embodiment of Fig. 4, the guide elements 20, 22, 22i, 24, 24i have support portions 25 (here hooks, alternatively, for example, openings, protrusions) by which the guide elements are supported by / at the guide element support structure 16. The guide element support structure 16 may be a structure of bars. The guide elements 20, 22, 22i, 24, 24i are, respectively, supported (held, fixed) by the support structure 16 made of bars / pipes. In particular, they may be fixed such that the guide elements are in predetermined positions with respect to each other to form the upflow chambers. The guide element support structure 16 may be constituted in a variety of ways known to skilled persons in the art and are not limited to the bars of the present embodiment. For example and without limitation, fewer or greater number of bars may be utilized.

[0165] Figs. 9 and 10 show possible patterns for the arrangement of guide elements in one level in a top view. The Figures show exemplarily three rows Rl, R2, and R3 and three lines LI, L2 and L3 of grow modules (in total nine grow modules). However, the disclosure is not limited thereto and the patterns may be increased to any higher number of rows and lines, which may also include different numbers for rows and lines. In Fig. 9, each row Rl, R2, R3 comprises three guide elements 14 having the same orientation, respectively. Adjacent rows differ from each other in that their grow modules are rotated by 90 degrees with respect to each other. In other words, in rows Rl and R3 with an uneven number, the first direction (stack direction) of the guide elements of each grow module 14 corresponds to the longitudinal direction X while in rows R2 with an even number, the first direction (stack direction) of the guide elements of each grow module 14 corresponds to the lateral direction Z.

[0166] Similar, Fig. 10 shows a checkerboard pattern wherein adjacent or neighboring grow modules in the longitudinal direction X and in the lateral direction Z are rotated by 90 degrees to each other.

[0167] Figs. 9 and 10 show embodiments, wherein adjacent grow modules are arranged close to each other. Although not shown in detail, it may be advantageous if adjacent guide elements even contact each other, optionally corresponding seal lips may be provided. The thus defined spaces between the adjacent guide elements and / or a tank wall may form downflow regions 62 (similar to the downflow regions described with respect to Fig. 4). Inparticular, Fig. 9 and 10 shows that such downflow regions are defined between the connection side wall 72 of a grow module 14 of one row and the connection side wall 72 of an adjacent grow module of the same row (e.g., Fig. 9, row 1) or between the connection side walls 72 of a grow module 14 and a side of a grow element of an adjacent grow module of a different row / line (e.g., Fig. 9 and 10).

[0168] In general, by arranging the grow modules close to each other, the extent of the downflow regions can be restricted as desired. Thus, a desired flow of growth medium through the downflow regions can be ensured thereby avoiding dead spaces where no or low flow is present. The rotated arrangement of grow modules further supports those dead spaces are reduced or avoided because the formation of laminar flows may be reduced or avoided.

[0169] The guide elements may also be supported such that they shiftable to a cleaning position where adjacent guide elements have a greater distance to each other. Alternatively, the guide elements are configured to be completely removable from the support structure.

[0170] Preferably, the support structure(s) 16 are designed such they can be removed from the tank 10 simply lifting it out of the tank by, for example, a lifting device, like conventional crane or a robot.

[0171] Furthermore, in the first embodiment, one, some or all of the guide elements and / or support structures preferably comprise(s) either a plug-and-play (plug / socket) connector 100a for connecting at least one of the gas introductions means and electrical wires for supplying the sensors and / or the light emitting means, and the light emitting means cooling device with the corresponding supply.

[0172] Furthermore, optionally downcomer tubes (downpipes, down spouts, return pipes) may be provided. Downcomer tubes are, on the upper side, in fluid connection with the interior volume of the tank at upper portions of side walls of the tank 10 close to the upper end of the of one of the upflow chambers or of a potential additional upflow area provided between a grow module and a tank side wall. On the lower side, the downcomer tubes are in fluid connection with the interior volume of the tank 10 at lower portions of a side wall adjacent to a downflow region.

[0173] The downflow regions may be changed to upflow chambers (or regions) by providing a corresponding pressurized gas introduction means in a lower portion of or below the chamber. Vice versa, one or more of the upflow chambers may be changed to downflowregions (chambers) by switching off or omitting the corresponding pressurized gas introduction means.

[0174] The bioreactors described above can be manufactured and mounted as follows: the tank (basin) may be made of made of conventional tank materials like steel, resin or composites. The guide element support structure may be made of conventional materials as e.g., composites, or steel.

[0175] The guide elements 20, 22, 22i, 24, 24i may be made from polypropylene or other type of plastic (polymer) plates 50, 54, 58, 52, 56, 60 which are then thermoformed to form two half shells (first plate and second plate). The plates are connected by adhesive or plastic welding (fusing) to form the respective guide elements 20, 22, 22i, 24, 24i. The light emitting means 74, light emitting means cooling device 74a, the guide element pressurized gas introduction means and / or corresponding wires, pipes, profiles and connectors are preferably mounted (accommodated, held) inside and / or on the guide elements 20, 22, 22i, 24, 24i.

[0176] The guide elements are mounted / fixed in or at the guide element support structure. Mounting or fixing may be supported by clamps, screws or corresponding means or mechanisms. Alternatively, simply hanging up the guide element on the support structure may also be sufficient. The guide elements may additionally be fixed to the adjacent ones before or after mounting to the guide element support structure.

[0177] Instead of mounting the guide elements to a guide element support structure, the guide elements may be fixed to each other, only. Fixing to each other may be performed by additional fixation means like clamps or screws but is not limited thereto. Alternatively, the guide elements comprise corresponding fixing means like protrusions or rims or grooves allowing fixation of adjacent guide elements. In this case one or more of the guide elements of one grow module is lifted by the lifting device in order to lift the whole grow module as a unit (with all its grow modules) out of the tank.

[0178] To initiate operation, the tank 10 is filled with growth medium 12 up to a defined upper level LI so that the guide elements are preferably completely immersed in the growth medium 12. Then light irradiation (illumination) and pressurized gas supply are started in order to facilitate the growth of the culture (e.g., one or more photoautotrophs) that has been inoculated into the growth medium 12. The growth medium 12 is circulated and mixed within the bioreactor 1 by the supply of pressurized gas into the tank 10.

[0179] For harvesting and / or cleaning, one or more of the grow modules are lifted out of the tank with their guide elements (as a unit). After lifting out, the guide elements are separated from each other by removing them from the guide element support structure or by simply increasing the distance between adjacent guide elements such that the guide elements have a minimum distance of at least 5cm, preferably 10cm and even more preferably 25cm.

[0180] Depending on the state of the grow process and state of the grow medium, the growth medium 12 may be discharged (drained) via a discharge means (port, opening, aperture, pump) such as a discharge (drainage) pipe. In this case, also the tank may be cleaned.

[0181] Cleaning of the tank and the grow modules may be performed by high pressure water jet cleaning (pressure washing).

[0182] It is explicitly stated that all features disclosed in the description and / or the claims are intended to be disclosed separately and independently from each other for the purpose of original disclosure as well as for the purpose of restricting the claimed invention independent of the composition of the features in the embodiments and / or the claims. It is explicitly stated that all value ranges or indications of groups of entities disclose every possible intermediate value or intermediate entity for the purpose of original disclosure as well as for the purpose of restricting the claimed invention, in particular as limits of value ranges.List of reference signs1 bioreactor10 tank12 growth medium14 grow module16 guide element support structure20 first guide element22 second guide element22i intermediate guide element(s)24 third guide element24i last guide element26 first flow chamber28 second flow chamber28i, 28ii third and further flow chamber(s)30, 32, 32i flow path34, 36, 38, 40 surface42, 44, 46, 48 protrusion portions43 (first type) protrusion portion cavity45 (second type) protrusion portion cavity47 planar portion50, 54, 58 first plates52, 56, 60 second plates62 downflow region66 inside surface of the tank side wallside wall connection side walls light emitting means a light emitting means cooling device b sensor connection side wall cavity bottom wall a grow module pressurized gas injection means / injectorb guide element pressurized gas injection means / injectorc tank pressurized gas injection means / injector gas cover / lid 0 power supply 0a plug-and-play connector 2 data processing device 4 pressurized gas supply 6 light emitting means cooling supply 8 lifting device 0 heat exchanger

Claims

Claims1. A bioreactor (1), preferably a photobioreactor, comprising a tank (10) adapted to contain a growth medium (12), and a plurality of grow modules provided within the tank (10), wherein each of the plurality of grow modules (14, 14a, 14b, 14c) comprises at least a first guide element (20), a second guide element (22), and a third guide element (24), the guide elements (20, 22, 24) being mounted to each other, or at least a first guide element (20), a second guide element (22), a third guide element (24), and a guide element support structure (16) to which the guide elements (20, 22, 24) are mounted to form the respective first grow module (14, 14a, 14b, 14c), the first, the second, and the third guide elements (20, 22, 24) of each of the plurality of grow modules (14, 14a, 14b, 14c) are, respectively, disposed next to each other in a first direction of the grow module and form a first flow chamber (26) defined between the first and the second guide elements (20, 22) and a second flow chamber (28) defined between the second and the third guide elements (22, 24), each of the plurality of grow modules is, with the guide elements (20, 22, 24) being mounted to each other or mounted to the guide element support structure (16), removably provided within the tank (10), and at least one of the plurality of grow modules (14, 14a, 14b, 14c) is removable from the tank (10) separately from at least another one of the plurality of grow modules (14, 14a, 14b, 14c).

2. The bioreactor (1) according to claim 1, characterized in that the first direction is a longitudinal direction (X) of the bioreactor or a lateral direction (Z) of the bioreactor, which is perpendicular to the longitudinal direction (X), the longitudinal direction (X) and the lateral direction (Z) being preferably perpendicular to a vertical direction (Y) of the bioreactor, and / or the first, the second, and the third guide elements (20, 22, 24) of each of the plurality of grow modules (14, 14a, 14b, 14c) define first and the second flow paths (30, 32) for the growth medium (12) which extend in the vertical direction (Y) through the respective first and second flow chambers (26, 28), and / orthe first and the second flow paths (30, 32) for the growth medium (12) have a waveform shape, a meandering shape, a zigzag shape, an undulating shape, or a sinusoidal shape, and / or the first and second flow chambers (26, 28) have a waveform shape, a meandering shape, a zigzag shape, an undulating shape, or a sinusoidal shape in a cross-sectional view perpendicular to a second direction of the grow module, which is perpendicular to the first direction and to the vertical direction of the corresponding grow module, wherein, preferably, the guide elements (20, 22, 24) defining a chamber at least partly overlap each other when viewed in the vertical direction.

3. The bioreactor (1) according to claim 1 or 2, characterized in that the grow modules (14) are arranged in a row (Rl, R2, R3), preferably several rows, on one level, and / or adjacent grow modules in one row (Rl, R2, R3) and / or in one line (LI, L2, L3) are rotated by 90 degrees to each other about the vertical direction (Y), and / or the grow modules (14a, 14b, 14c) or the rows (Rl, R2, R3) of the grow modules are stacked or arranged on top of each other in the vertical direction (Y), wherein, preferably, grow modules stacked or arranged on top of each other are rotated by 90 degrees to each other about the vertical direction (Y), and / or at least one, preferably each of the plurality of grow modules (14, 14a, 14b, 14c) is removable from the tank (10) separately from at least another one of the plurality of grow modules (14, 14a, 14b, 14c).

4. The bioreactor according to any one of claims 1 to 3, characterized in that the guide elements are mounted to each other or to the guide element support structure in a non-destructive demountable and re-mountable manner, and / or the first, the second, and the third guide elements (20, 22, 24) of each of the plurality of grow modules (14, 14a, 14b, 14c) are separable from and re-mountable to each other and / or separable from and re-mountable to the guide element support structure (16) at least when they are removed from the tank (10) such that, preferably, surfaces (34, 36, 38, 40) of the guide elements (20, 22, 24) defining the flow chambers (26, 28) in the mounted state are cleanable.

5. The bioreactor according to any one of claims 1 to 4, characterized in thateach of the plurality of grow modules (14, 14a, 14b, 14c) is equipped with at least one of a light emitting means (74), preferably provided within or on at least one, preferably each, of the plurality of guide elements (20, 22, 24) for irradiating the growth medium (12) within the flow chambers (26, 28) with light, a light emitting means cooling device (74a) for cooling the light emitting means (74), and a sensor (74b).

6. The bioreactor according to any one of claims 1 to 5, characterized in that each of at least a first subset of the plurality of grow modules (14a) comprises a grow module pressurized gas introduction means (77a) provided below the flow chambers of the corresponding grow module (26, 28, 28i) or in a vertical lower portion of the flow chambers (26, 28, 28i) of the corresponding grow module which are configured to introduce pressurized gas (84) into the flow chambers, and / or at least one, preferably all, of the guide elements (20, 22, 24) of at least a (the) first subset of the plurality of grow modules (14a) comprise(s) in a vertical lower portion of the guide element respective guide element pressurized gas introduction means (77b) which are configured to introduce pressurized gas (84) into the respective flow chambers, and / or a tank pressurized gas introduction means (77a) is provided in a bottom portion of the tank (10) below the plurality of grow modules (14), the tank gas introduction means (77a) being configured to introduce pressurized gas (84), preferably such that the introduced gas (84) is moving upward into the flow chambers (26, 28, 28i).

7. The bioreactor according to claim 6, characterized in that the first subset of the plurality of grow modules (14a) is arranged on or close to a bottom wall (76) of the tank or forms the lowest level of grow modules (14a), and the plurality of grow modules comprises preferably a second subset of the plurality of grow modules (14b, 14c) which are arranged on top of or above at least a part of, preferably all of the first subset of the plurality of grow modules (14a), wherein at least a part of, preferable all, of the plurality of grow modules (14b) or guide elements of the second subset is not equipped with or does not comprise a pressurized gas introduction means.

8. The bioreactor according to claim 5, or claims 6 or 7 if dependent on claim 5, further comprising at least one of a power supply (100), a data processing device (102), a pressurized gas supply (104), and a light emitting means cooling supply (106), wherein the respective light emitting means (74) is connected, preferably via a plug-and-play connector (100a), with the power supply (100) and / or the respective sensor (74b) is connected, preferably via a plug-and-play connector (100a), with the data processing device (102) and / or the respective pressurized gas introduction means (77, 77a) is connected, preferably via a plug-and-play connector (100a), with the pressurized gas supply (104), and / or the respective light emitting means cooling device (74a) is connected, preferably via a plug- and-play connector (100a), with the light emitting means cooling supply (106).

9. The bioreactor according to any one of claims 1 to 8, characterized in that the first guide element (20) of each of the plurality of grow modules (14) comprises, at least on a side partially defining the first flow chamber (26), a plurality of protrusion portions (42) respectively protruding towards the second guide element (22), the second guide element (22) of each of the plurality of grow modules comprises, on a first side partially defining the first flow chamber (26), a plurality of first protrusion portions (44) protruding towards the first guide element (20) and, on a second side partially defining the second flow chamber (28), a plurality of second protrusion portions (46) protruding towards the third guide element (24), and the third guide element (24) of each of the plurality of grow modules comprises, at least on a side partially defining the second flow chamber (28), a plurality of protrusion portions (48) respectively protruding towards the second guide element (22), wherein: the protrusion portions (42) of the first guide element (20) and the first protrusion portions (44) of the second guide element (22) that together define the first flow chamber (26) are, in the vertical direction (Y), disposed on the first and the second guide elements (20, 22) in an alternating manner, and the second protrusion portions (46) of the second guide element (22) and the protrusion portions (48) of the third guide element (24) that together define the second flowchamber (28) are, in the vertical direction (Y), disposed on the second and the third guide elements (22, 24) in an alternating manner, and preferably, the protrusion portions (42) of the first guide element (20) and the first protrusion portions (44) of the second guide element (22) that together define the first flow chamber (26) at least partly overlap each other when viewed in the vertical direction, and / or preferably the second protrusion portions (46) of the second guide element (22) and the protrusion portions (48) of the third guide element (24) that together define the second flow chamber (28) at least partly overlap each other when viewed in the vertical direction.

10. The bioreactor according to claim 9, characterized in that the first guide element (20) comprises a first plate (50) attached to a second plate (52) that is partially parallel to the first plate (50), the second plate (52) partially defining the first flow chamber (26) and comprising the protrusion portions (42) which are preferably formed by thermoforming, and / or the second guide element (22) comprises a first plate (54) attached to a second plate (56) that is partially parallel to the first plate (54), the first plate (54) partially defining the first flow chamber (26) and the second plate (56) partially defining the second flow chamber (28), the first plate (54) of the second guide element (22) having the first protrusion portions (44) and the second plate (56) of the second guide element (22) having the second protrusion portions (46) which are preferably formed by thermoforming, and / or the third guide element (24) comprises a first plate (58) attached to a second plate (60) that is partially parallel to the first plate (58), the first plate (58) partially defining the second flow chamber (28) and comprising the protrusion portions (48) which are preferably formed by thermoforming.

11. The bioreactor according to any one of claims 1 to 10, characterized in that the guide elements (20, 22, 24) of the grow modules are, respectively, disposed next to each other as an array in the first direction (X), which is perpendicular to the vertical direction (Y), and comprise, in the first direction (X), in the following sequence, the first guide element (20), at least two intermediate guide elements (22i), two of which are the second and third guide elements (22, 24), and a last guide element (24i) in the first direction, and a third flow chamber (28i) is defined between the last guide element (24i) and an adjacent one of the intermediate guide elements (22i).

12. The bioreactor according to claim 11, characterized in that both sides of each of the intermediate guide elements (22i) comprise a plurality of protrusion portions (44, 46, 48, 60) protruding towards an adjacent one of the guide elements, and a side of the last guide element (24i) facing the adjacent one of the intermediate guide elements (22i) comprises a plurality of protrusion portions protruding towards the adjacent one of the intermediate guide elements (22i) such that flow chambers (26, 28, 28i) two of which are the first and second flow chambers (26, 28), are respectively defined between the first guide element (20) and an adjacent one of the intermediate guide elements (22i), between each pair of adjacent ones of the intermediate guide elements (22i), and between the side of the last guide element (24i) and an adjacent one of the intermediate guide elements (22i), each of the flow chambers (26, 28, 28i) having a waveform shape, a meandering shape, a zigzag shape, an undulating shape, or a sinusoidal shape in a cross-sectional view perpendicular to a second direction, which is perpendicular to the first direction and to the vertical direction of the corresponding grow module.

13. The bioreactor according to claim 9 or any one of claims 10 to 12, if being dependent on claim 9 and claim 5, characterized by further comprising the light emitting means (74) and / or the light emitting means cooling device (74a) are provided inside at least one of, preferably all of, the protrusion portions (42, 44, 46, 48).

14. The bioreactor according to any one of claims 1 to 13, characterized by further comprising at least one heat exchange^ 110), which is provided at or on a lower region of at least one of the tank side walls (68), and / or between adjacent grow modules (14) of the plurality of grow modules or between adjacent rows (R) of grow modules of the plurality of grow modules.

15. The bioreactor according to any one of claims 1 to 14, characterized in that at least one, preferably all, of inner surfaces (66) of the tank walls (68), outer surfaces of the grow modules (14), and outer surfaces of the heat exchangers(l 10), are provided with an antifouling and / or anti-sticking and / or luminous and / or luminescent coating.

16. Method of cleaning the bioreactor according to any one of claims 1 to 15, comprising the steps offirstly removing at least one of the grow modules (14, 14a, 14b, 14c) from the tank(10), subsequently, at least one of separating the first, the second, and the third guide elements (20, 22, 24) of the removed grow module (14, 14a, 14b, 14c) from the corresponding guide element support structure (16) and, preferably, thereby separating the first, the second, and the third guide elements (20, 22, 24) of the removed grow module (14, 14a, 14b, 14c) from each other, and / or separating the first, the second, and the third guide elements (20, 22, 24) from the removed grow module (14, 14a, 14b, 14c) from each other, and / or moving the at least one of the guide elements (20, 22, 24) of the removed grow module (14, 14a, 14b, 14c) with respect to another one, subsequently cleaning the guide elements (20, 22, 24) separated from each other or moved with respect to each other, and optionally, subsequently remounting the cleaned guide elements to each other or to the corresponding guide element support structure to remount the corresponding grow module and providing the remounted grow module in the tank.

17. A bioreactor (1), preferably a photobioreactor, comprising a tank (10) adapted to contain a growth medium (12), and groups of guide elements mounted within the tank, each group each group comprising at least a first guide element (20), a second guide element (22), and a third guide element (24), wherein the first, the second and the third guide elements (20, 22, 24) of the respective group are disposed next to each other in a longitudinal direction (X) such that a first flow chamber (26) is defined between the first and the second guide elements (20, 22) and a second flow chamber (28) is defined between the second and the third guide elements (22, 24), the groups of the first, the second and the third guide elements (20, 22, 24) are removably mounted within the tank (10), and the first, the second and the third guide elements (20, 22, 24) of the respective group are configured to be separable from each other at least when the respective group is removed from the tank (10).

18. The bioreactor according to claim 17, whereinthe guide elements (20, 22, 24) of the respective group are disposed next to each other as an array in the longitudinal direction (X), which is perpendicular to the vertical direction (Y), and comprise, in the longitudinal direction (X), in the following sequence, the first guide element (20), at least two intermediate guide elements (22i), two of which are the second and third guide elements (22, 24), and a last guide element (24i) in the longitudinal direction (X), and a third flow chamber (28i) is defined between the last guide element (24i) and an adjacent one of the intermediate guide elements (22i).

19. The bioreactor according to claim 18 or 19, wherein the first and second flow chambers (26, 28) have a waveform shape, a meandering shape, a zigzag shape, an undulating shape or a sinusoidal shape in a cross-sectional view perpendicular to a lateral direction (Z), which is perpendicular to the longitudinal direction (X) and a vertical direction (Y), and / or the guide elements (20, 22, 24) of the groups are provided within the tank (10) such that preferably the guide elements (20, 22, 24) are at least partially immersed in the growth medium (12) when the tank (10) contains the growth medium (12).

20. Method of cleaning the bioreactor according to any one of claims 17 to 20, comprising the steps of firstly removing at least one of the groups from the tank (10), subsequently moving the first, the second, and the third guide elements (20, 22, 24) of the respective group from each other or moving the guide elements with respect to each other, subsequently cleaning the separated or moved guide elements (20, 22, 24), and optionally, subsequently connecting the cleaned guide elements to each other to form a group and remounting the group of guide elements in the tank.

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