Microplate lighting systems and methods

Abstract

Systems and methods for illuminating a plurality of microplates. An example lighting system comprises a plurality of light sources. Each light source of the plurality of light sources may be operable to illuminate a corresponding microplate of a plurality of microplates. The plurality of light sources may be alternatingly stackable with the plurality of microplates.

Description

[0001] MICROPLATE LIGHTING SYSTEMS AND METHODS

[0002] RELATED APPLICATION:

[0003] This application claims the benefit of, and priority to, United States provisional patent application no. 63 / 636,269 filed April 19, 2024. The entire contents of United States provisional patent application no. 63 / 636,269 are incorporated by reference herein.

[0004] FIELD:

[0005] This invention is in the field of lighting systems, and in particular relates to lighting systems used to illuminate microplates which may comprise microorganisms.

[0006] BACKGROUND:

[0007] Selection of strains and manipulation of gene activity in photosynthetic microorganisms may offer the possibility of producing energy and materials directly from sunlight, water and carbon dioxide (CO2) thereby contributing directly to more holistic modes of food production, innovative bioproducts and reliable bioenergy solutions that may reduce human carbon emissions. Despite their recognized potential, current applications of photosynthetic microorganisms, primarily cyanobacterial host chassis, as microbial cell factories remain in early stages of development. This is partly due to a limited number of tractable genetic systems compounded by a paucity of platforms supporting high-throughput cultivation at laboratory scale. The paucity of platforms may make it difficult to conduct functional screens, select strains or optimize growth conditions for energy and materials production using multifactorial experimental design.

[0008] Standard flask and photobioreactor-based cultivation systems currently may limit throughput to 10s of individual conditions or strains. One of the reasons for this constraint is that microalgal cultures are highly sensitive to changes in growth conditions (such as changes to lighting conditions). Several strategies have been employed to increase throughput of microalgal screening with varying trade-offs associated with each method.

[0009] Pooled selection allows for targeted enrichment of 10,000s to 1,000,000s of distinct genotypes for strains that perform best under specific growth conditions. Although this strategy can be useful for large library screening, the desired phenotype may need to provide a fitness benefit and all strains may be subjected to the same set of growth conditions. This can be invaluable in recovering strains that grow under extremes of pH, temperature, or salinity, etc., but may not be transferrable to screening paradigms investigating specific biosynthetic processes or traits not directly associated with growth rate. Individual strains from the resulting enrichment may still require isolation and validation at scale therefore potentially limiting knowledge translation.

[0010] Droplet- or flow-cytometry-based screening is an alternative solution involving the encapsulation of individual cells in droplets that can be incubated before sorting or direct sorting of cells based on fluorescence or absorbance. This strategy enables the screening of 10,000s to 100,000s of distinct genotypes, the application of alternative assays and generation of concentration gradients within droplets.

[0011] Although, multiple rounds of either selection or droplet-based screening can lead to hit enrichment, both methods may be likely to result in false-positives that require extensive rounds of downstream isolate validation.

[0012] Microplate or micro-photobioreactor (micro-PBR)-based screening systems have been explored to enable intermediate-throughput screening of 10s to 1000s of individual cultures. Although this throughput is limited in comparison to pooled and droplet-based screening, the format of these systems enables the testing of distinct medium compositions on clonal populations or synthetic consortia under a wide range of growth conditions. The optimization of medium compositions, through the parallel testing of distinct growth conditions may enable the identification of limiting resources and shifting of selective pressures to drive processes of interest which may be a prerequisite for metabolic engineering applications which are often selected against under standard cultivation conditions. However, current lighting systems developed for microplate screening or for optogenetics may include either specialized stand-alone devices which cannot illuminate more than a single microplate at a time or devices requiring manual placement of microplates across an illuminated surface also with limited throughput.

[0013] Improved lighting systems which may be used to illuminate microplates are desirable. SUMMARY:

[0014] According to one aspect of the present invention, there is provided a lighting system for illuminating a plurality of microplates. The lighting system may comprise a plurality of light sources. Each light source of the plurality of light sources may be operable to illuminate a corresponding microplate of the plurality of microplates. The plurality of light sources may be alternatingly stackable with the plurality of microplates.

[0015] In some embodiments, each light source of the plurality of light sources is operable to simultaneously illuminate the corresponding microplate of the plurality of microplates.

[0016] In some embodiments, each light source of the plurality of light sources is operable to consistently illuminate the corresponding microplate of the plurality of microplates.

[0017] In some embodiments, each light source of the plurality of light sources is operable to emit light of equal intensity.

[0018] In some embodiments, each light source of the plurality of light sources is operable to emit an equal spectrum of light.

[0019] In some embodiments, each light source of the plurality of light sources comprises: a substrate; and a plurality of light emitters supported by the substrate.

[0020] In some embodiments, the plurality of light emitters are arranged on the substrate in a grid comprising a plurality of rows and a plurality of columns.

[0021] In some embodiments, a spacing between adjacent ones of the plurality of light emitters is equal.

[0022] In some embodiments, each of the plurality of light emitters is the same.

[0023] In some embodiments, each light emitter of the plurality of light emitters is individually controllable. In some embodiments, a wavelength of light emitted by each light emitter of the plurality of light emitters is variable.

[0024] In some embodiments, an intensity of light emitted by each light emitter of the plurality of light emitters is variable.

[0025] In some embodiments, the plurality of light emitters comprises a plurality of light emitting diodes (LEDs).

[0026] In some embodiments, the plurality of light emitters emit light having a wavelength in a range from about 400 nm to about 750 nm.

[0027] In some embodiments, the plurality of light emitters comprises at least 384 light emitters.

[0028] In some embodiments, the substrate distributes heat across the substrate and away from the plurality of light emitters.

[0029] In some embodiments, the substrate distributes heat evenly across the substrate.

[0030] In some embodiments, the substrate comprises a superconducting aluminum plate.

[0031] In some embodiments, each light source of the plurality of light sources has a height that is less than 2 mm.

[0032] In some embodiments, the plurality of light sources comprises at least 50 light sources.

[0033] In some embodiments, the lighting system further comprises a plurality of supporting frames, each supporting frame configured to support a corresponding light source of the plurality of light sources.

[0034] In some embodiments, the plurality of supporting frames is alternatingly stackable with the plurality of microplates. According to another aspect of the present invention, there is provided a method for illuminating microorganisms in a plurality of microplates. The method may comprise: alternatingly stacking a plurality of light sources and the plurality of microplates; and illuminating each microplate of the plurality of microplates with a corresponding light source of the plurality of light sources.

[0035] In some embodiments, alternatingly stacking the plurality of light sources and the plurality of microplates comprises positioning each microplate of the plurality of microplates above the corresponding light source of the plurality of light sources.

[0036] In some embodiments, alternatingly stacking the plurality of light sources and the plurality of microplates comprises positioning each microplate of the plurality of microplates below the corresponding light source of the plurality of light sources.

[0037] In some embodiments, illuminating each microplate of the plurality of microplates comprises illuminating each microplate of the plurality of microplates with light of equal intensity.

[0038] In some embodiments, illuminating each microplate of the plurality of microplates comprises illuminating each microplate of the plurality of microplates with an equal spectrum of light.

[0039] In some embodiments, the method further comprises supporting each of the light sources of the plurality of light sources with a corresponding supporting frame to position each light source of the plurality of light sources closer to the corresponding microplate of the plurality of microplates.

[0040] In some embodiments, the method further comprises simultaneously varying an intensity of light emitted by each light source of the plurality of light sources.

[0041] In some embodiments, the method further comprises simultaneously varying a spectrum of light emitted by each light source of the plurality of light sources.

[0042] BRIEF DESCRIPTION OF THE DRAWINGS:

[0043] While the invention is claimed in the concluding portions thereof, example embodiments are provided in the accompanying detailed description which may be best understood in conjunction with the accompanying diagrams where like parts in each of the several diagrams are labeled with like numerals, and where:

[0044] Figure 1 is a schematic view of an embodiment of the lighting system of the present invention;

[0045] Figure 2 is a top plan view of an embodiment of a light source of the lighting system of Figure 1;

[0046] Figure 3 is a side view of the light source of Figure 2;

[0047] Figure 4 is a top plan view of an embodiment of a supporting frame of the lighting system of Figure 1;

[0048] Figure 5 is a side view of the supporting frame of Figure 5;

[0049] Figure 6A is an example plot illustrating experimental data;

[0050] Figure 6B is an example plot illustrating experimental data;

[0051] Figure 6C is an example plot illustrating experimental data;

[0052] Figure 6D is an example plot illustrating experimental data;

[0053] Figure 6E is an example plot illustrating experimental data;

[0054] Figure 6F is an example plot illustrating experimental data;

[0055] Figure 7A is an example plot illustrating experimental data;

[0056] Figure 7B is an example plot illustrating experimental data;

[0057] Figure 7C is an example plot illustrating experimental data; Figure 7D is an example plot illustrating experimental data;

[0058] Figure 8A is an example plot illustrating example response surface models;

[0059] Figure 8B is an example plot illustrating experimental data;

[0060] Figure 8C is an example plot illustrating experimental data;

[0061] Figure 9A is an example plot illustrating experimental data;

[0062] Figure 9B is an example plot illustrating experimental data;

[0063] Figure 9C is an example plot illustrating experimental data;

[0064] Figure 9D is an example plot illustrating experimental data;

[0065] Figure 9E is an example plot illustrating experimental data;

[0066] Figure 9F is an example plot illustrating experimental data;

[0067] Figure 9G is an example plot illustrating experimental data;

[0068] Figure 9H is an example plot illustrating experimental data;

[0069] Figure 9I is an example plot illustrating experimental data; and

[0070] Figure 9J is an example plot illustrating experimental data.

[0071] DETAILED DESCRIPTION:

[0072] The following discussion provides many example embodiments of the inventive subject matter. Although each embodiment represents a single combination of inventive elements, the inventive subject matter is considered to include all possible combinations of the disclosed elements. Aspects of the invention described herein include a lighting system which may be operable to illuminate microplates which may comprise microorganisms. For example, a lighting system described herein may provide consistent lighting (e.g., lighting of consistent intensity and / or wavelength) across and between cell culture microplates within standard laboratory automation infrastructure. The lighting system described herein may be used for the cultivation of phototrophic microorganisms comprising microalgae or cyanobacteria. Additionally, or alternatively, the lighting system described herein may be used in functional screening of cell culture microplates for light-dependent enzymes, pathways, or regulatory networks.

[0073] Figure 1 schematically illustrates an example embodiment of a lighting system 100. The lighting system 100 may be used to illuminate a plurality of microplates. A “microplate” described herein may be, or include, a plate which comprises a plurality of wells. A well of the microplate may comprise one or more microorganisms.

[0074] The lighting system 100 comprises a plurality of light sources 110 (such as light sources 110-1 , 110-2, 110-3, ... , 110-N, for example). A light source 110 may illuminate a corresponding microplate 112. For example, light source 110-1 may illuminate a microplate 112-1 , light source 110-2 may illuminate a microplate 112-2, light source 110-3 may illuminate a microplate 112-3, light source 110-N may illuminate a microplate 112-N, etc. A light source 110 illuminating a corresponding microplate 112 may include the light source 110 illuminating wells of the corresponding microplate 112.

[0075] The plurality of light sources 110 and microplates 112 may be stacked. In the illustrated embodiment of Figure 1, the plurality of light sources 110 and microplates 112 are vertically stacked on a stacker 120. In some embodiments, the light sources 110 and microplates 112 are stacked in alternating positions to allow loading of a microplate 112 directly above (or below) a light source 110. The stacker 120 may be, or include, a commercially available stacker such as a stacker of a Cytomat 5 C450 incubator from Thermo Fisher Scientific™ or a stacker of a Sanyo MCO-175M Water Jacketed CO2 incubator from Panasonic™, for example.

[0076] The stacker 120 may comprise a frame 122 and plural spaced apart sets of opposing brackets 124 connected to the frame 122. A set of brackets 124 may, for example, support a microplate 112 on the stacker 120. In the illustrated embodiment of Figure 1, a vertical distance between a first set of opposing brackets 124 (such as brackets 124-1 and 124-2, for example) and a second set of opposing brackets (such as brackets 124-3 and 124-4, for example) corresponds to a vertical height of a microplate 112. In some such embodiments, a first set of opposing brackets 124 may support a light source 110 and a second set of opposing brackets 124 immediately above the first set of opposing brackets 124 supports a corresponding microplate 112.

[0077] As described elsewhere herein, it may be desirable to position a light source 110 close to (or as close as possible to) a bottom surface of the corresponding microplate 112. A supporting frame 114, may, for example, position a light source 110 closer to a bottom surface of the corresponding microplate 112. Additionally, the supporting frame 114 may support the light source 110 within a stack (such as within a stack on stacker 120, for example).

[0078] In the illustrated embodiment of Figure 1 , microplate 112-1 is positioned on an uppermost stacking position of the stacker 120. Immediately below the microplate 112-1 on the next stacking position of the stacker 120, is the corresponding light source 110-1 which is supported by the corresponding supporting frame 114-1. Immediately below the supporting frame 114-1 on the next stacking position of the stacker 120, is the microplate 112-2. Immediately below the microplate 112-2 on the next stacking position of the stacker 120 is the corresponding light source 110-2 which is supported by the corresponding supporting frame 114-2. Immediately below the supporting frame 114-2 on the next stacking position of the stacker 120, is the microplate 112-3 supported by brackets 124-3 and 124-4 of the stacker 120. Immediately below the microplate 112-3 on the next stacking position of the stacker 120 is the corresponding light source 110-3 which is supported by the corresponding supporting frame 114-3. The supporting frame 114-3 is supported by brackets 124-1 and 124-2 of the stacker 120. In the illustrated embodiment of Figure 1, the microplate 112-3, the light source 110-3 and the supporting frame 114-3 are illustrated as removed from the stack of the stacker 120 for illustrative purposes.

[0079] A supporting frame 114 may have a spatial footprint that corresponds to a spatial footprint of a microplate 112 (e.g. approximately equal height, length and / or width). A supporting frame 114 which has a spatial footprint that corresponds to a spatial footprint of a microplate 112 may be easily stacked onto commercially available stackers 120 which are designed to stack microplates 112. The lighting system 100 may also comprise a driving circuit 130. The driving circuit 130 is operable to provide electric power to the plurality of light sources 110. The driving circuit 130 may, for example, receive as input electric power 132 (such as 110V 60Hz AC power, for example). The driving circuit 130 may convert the input electric power 132 into output electric power (such as 48V DC power, for example) to be provided to the plurality of light sources 110.

[0080] The driving circuit 130 may comprise one or more circuit components operable to power the plurality of light sources 110 as desired such as one or more amplifiers, diodes, voltage regulators, voltage converters, transformers, resistors, capacitors, inductors, etc.

[0081] The driving circuit 130 may control a voltage and / or current of electrical power that is supplied to the light sources 110 of the lighting system 100.

[0082] In some embodiments, the driving circuit 130 simultaneously (e.g. all together in unison) powers the light sources 110 of the lighting system 100.

[0083] In the illustrated embodiment of Figure 1, the output electric power from the driving circuit 130 is provided to the plurality of light sources 110 via a first power terminal 137 (e.g. a positive polarity terminal) and a second power terminal 138 (e.g. a negative polarity terminal). Each of the plurality of light sources 110 may be electrically connected to the first and second power terminals 137 and 138. Having a universal power connection for the plurality of light sources 110 may simplify wiring of the lighting system 100 (e.g. do not need to run individual electrical connections from each light source 110 to the driving circuit 130).

[0084] The first power terminal 137 may be electrically connected to the driving circuit 130 with electrical connections 133 and 135 and the second power terminal 138 may be electrically connected to the driving circuit 130 with electrical connections 134 and 136. The light source 110-3 may, for example, be connected to the first power terminal 137 with electrical connection 139 and to the second power terminal 138 with electrical connection 140.

[0085] The first power terminal 137 and the second power terminal 138 may be connected (or attached) to the stacker 120 such that the first and second power terminals 137 and 138 rotate with the stacker 120 if the stacker 120 is rotated. Varying the delivery of electrical power to the plurality of light sources 110 may vary one or more characteristics of light emitted by the plurality of light sources 110. For example, varying the delivery of electrical power to the plurality of light sources 110 may vary an intensity of light emitted by the plurality of light sources 110.

[0086] The lighting system 100 may also comprise a controller 150. The controller 150 may be configured to control the driving circuit 130 to provide the desired electrical power to the plurality of light sources 110. Additionally, or alternatively, the controller 150 may be configured to control which ones of the plurality of light sources 110 is active (e.g. turned on to emit light) at any given time. For example, the controller 150 may control the light source 110-1 to emit light and the light source 110-2 to not emit light. Additionally, or alternatively, the controller 150 may be configured to control one or more characteristics of individual light emitters of a particular light source 110 (such as, for example) whether an individual light emitter is turned on or off to emit light, at what wavelength of light a light emitter emits light at, etc.).

[0087] The controller 150 may be, or include, a user computing device, a server computing device, a personal computer, a laptop computer, a tablet computer, a smartphone, a network node for a computer network, a router for a computer network, a mobile device, a telephone, or one more other devices including one or more other computing devices as described herein, or a combination of two or more thereof. In some embodiments, the controller 150 is, or includes, a central processing unit (CPU), one or more microprocessors, one or more analog circuits, one or more configurable logic blocks, one or more application-specific integrated circuits (ASICs) or one or more field programmable gate arrays (FPGAs).

[0088] In some embodiments, the driving circuit 130 includes, or integrates, the controller 150.

[0089] In some embodiments, the driving circuit 130 (or the controller 150) simultaneously controls the light sources 110 in unison (e.g., whether the light sources 110 should all be powered on or off, what intensity of light should the light sources 110 emit, what spectrum of light should the light sources 110 emit, etc.).

[0090] Once the plurality of light sources 110 and the plurality of microplates 112 have been stacked on the stacker 120 as desired, the stacker 120 may be placed into, for example, an incubator. The driving circuit 130 may be external to the incubator. To facilitate rotation of the stacker 120 within the incubator, electrical connection 133 may be electrically connected to electrical connection 135 and electrical connection 134 may be electrically connected to electrical connection 136 with a slipring connector 160. The slipring connector 160 may maintain the electrical connection between electrical connections 133 and 135 and between electrical connections 134 and 136 while permitting electrical connection 133 to rotate relative to electrical connection 135 and permitting electrical connection 134 to rotate relative to electrical connection 136. In some embodiments, the slipring connector 160 is connected to a ceiling of an incubator (such as to a grate of a ceiling of an incubator, for example).

[0091] Figure 2 illustrates an example embodiment of a light source 110.

[0092] The light source 110 may comprise a plurality of light emitters 204. Each of the light emitters 204 is operable to emit light. In the illustrated embodiment of Figure 2, the light source 110 comprises 384 light emitters 204 (e.g. light emitters 204-1, 204-2, ... , 204-383 and 204-384). However, the light source 110 may comprise any number of light emitters 204. The light emitted by the plurality of light emitters 204 may be used to illuminate wells of a microplate 212 or a microplate 212 generally.

[0093] In some embodiments, a light emitter 204 is operable to illuminate a single corresponding well of a microplate 212. In some embodiments, a light emitter 204 is operable to illuminate a plurality of wells of a microplate 212 (e.g. a light emitter 204 illuminates two or more wells of a microplate 212). In some embodiments, a plurality of light emitters 204 are operable to illuminate a single well of a microplate 212 (e.g. two or more light emitters 204 illuminate a well of a microplate 212).

[0094] The plurality of light emitters 204 may be supported by, or on, a substrate 202. The substrate 202 may distribute heat generated by the plurality of light emitters 204 across the substrate 202. Distributing heat generated by the plurality of light emitters 204 across the substrate 202 may assist with maintaining each of the light emitters 204 at an approximately equal operating temperature. In some embodiments, the substrate 202 distributes heat generated by the plurality of light emitters 204 approximately evenly (or evenly) across the substrate 202.

[0095] In some embodiments, at least some of the light emitters 204 are at least partially embedded in the substrate 202. The substrate 202 may, for example, be, or include, a superconducting aluminum plate, a cooper plate, etc.

[0096] The plurality of light emitters 204 may be arranged on the substrate 202 in a desired arrangement. The desired arrangement may correspond to an arrangement of wells of a microplate 112 (e.g., the spacing and / or positioning of the light emitters 204 may correspond to the spacing and / or positioning of the wells of the microplate 112). For example, if each light emitter 204 is to illuminate a single well of a microplate 112 and the wells of the microplate 112 are arranged in a grid, the light emitters 204 of the light source 110 may be arranged in a corresponding grid pattern.

[0097] In some embodiments, adjacent light emitters 204 are equally spaced from one another on the substrate 202.

[0098] In the illustrated embodiment of Figure 2, the light emitters 204 are arranged in a grid. As oriented in Figure 2, the light emitters 204 are arranged in a grid comprising 24 columns (e.g., columns 206-1, 206-2, ... , 206-23 and 206-24) and 16 rows (e.g., rows 207-1 , 207-2, ... , 207-15 and 207-16). The grid shown in Figure 2 may correspond to a grid of a 384 well microplate.

[0099] In the illustrated embodiment of Figure 2, the positions of the light emitters 204 match the positions of the wells in a 384 well microplate (e.g. the position of each light emitter 204 matches the position of the corresponding well of the microplate). However, this is not necessary in all embodiments.

[0100] In the illustrated embodiment of Figure 2, the light source 110 comprises a first electrical connection member 212 (e.g. a positive polarity electrical connection member) and a second electrical connection member 214 (e.g. a negative polarity electrical connection member). For example, the first electrical connection member 212 may be electrically connected to the first power terminal 137 and the second electrical connection member 214 may be electrically connected to the second power terminal 138. The light emitters 204 may be electrically connected to the first and second electrical connection members 212 and 214. Although in the illustrated embodiment of Figure 2, the light source 110 only comprises first and second electrical connection members 212 and 214, the light source 110 may comprise additional electrical connection members. For example, a light source 110 may comprise more than two electrical connection members.

[0101] In the illustrated embodiment of Figure 2, light emitters 204 of a column 206 (i.e., 16 light emitters 204 in total) are electrically connected in series, and each of the columns 206 is electrically connected in parallel to the first and second electrical connection members 212 and 214. However, the light emitters 204 of a light source 110 may be electrically connected in any suitable manner.

[0102] A light emitter 204 may be, or include, a light emitting diode (LED). However, a light emitter 204 need not be a LED. In some embodiments, a light emitter 204 is, or includes, a broad spectrum LED operable to emit light having a wavelength in a range from about 400nm to about 750nm. In some embodiments, a light emitter 204 is a LED operable to emit light having a spectrum of 4044K. In some embodiments, a light emitter 204 is a LED operable to emit light having a spectrum of 5091 K. In some embodiments, a light emitter 204 is a LED operable to emit light having a spectrum of 6083K.

[0103] In some embodiments, a column 206 of light emitters 204 comprising an array of LEDs is powered with electrical power having a voltage of about 48 V and current of up to about 150 mA.

[0104] In some embodiments, the light emitters 204 of a light source 110 are all controlled together. For example, all of the light emitters 204 of a light source 110 may be controlled (such as by the controller 150, for example) to emit light in unison (e.g. at the same time for the same duration of time). In some embodiments, groups or sub-groups of light emitters 204 may be controlled together. For example, a group of four light-emitters 204 may be controlled (such as by the controller 150, for example) to emit light in unison. In some embodiments, the light emitters 204 of a light source 110 are individually controllable. For example, a light emitter 204 may be controlled (such as by the controller 150, for example) to emit light independently of any other light emitter 204 of a light source 204. The light emitters 204 may be configured to emit visible light (e.g., light having a wavelength in a range from about 380 nm to about 780 nm). However, the light emitters 204 need not emit visible light.

[0105] In some embodiments, at least one light emitter 204 may be tunable to emit a desired wavelength of light. For example, the controller 150 may control one or more light emitters 204 of a light source 110 to emit a desired wavelength of light.

[0106] In some embodiments, a light intensity of light emitted by at least one light emitter 204 may be varied. For example, the controller 150 may control one or more light emitters 204 of a light source 110 to emit a desired intensity of light.

[0107] In some embodiments, an intensity of light emitted by a light emitter 204 (or a light source 110) may be varied in a range from about 50 pmol / m2 / s to about 500 pmol / m2 / s.

[0108] In some embodiments, each light emitter 204 of a light source 110 emits light of consistent intensity and / or spectrum. In some embodiments, each light source 110 of the lighting system 100 emits light of consistent intensity and / or spectrum.

[0109] Light of consistent intensity may mean that a light intensity of light emitted by a first light emitter 204 (or a first light source 110) is equal to a light intensity of light emitted by a second light emitter 204 (or a second light source 110). In this context, equal to may mean that the light intensity of light emitted by the first light emitter 204 (or the first light source 110) is identical, or is substantially identical (e.g. the variance is at most ±1%, 2%, 5% or 10%), to the light intensity of light emitted by the second light emitter 204 (or the second light source 110).

[0110] Light of consistent spectrum may mean that a spectrum of light emitted by a first light emitter 204 (or a first light source 110) is equal to a spectrum of light emitted by a second light emitter 204 (or a second light source 110). In this context, equal to may mean that the spectrum of light emitted by the first light emitter 204 (or the first light source 110) is identical, or is substantially identical (e.g. the variance is at most ±1%, 2%, 5% or 10%), to the spectrum of light emitted by the second light emitter 204 (or the second light source 110). In some embodiments, each light source 110 of the lighting system 100 may simultaneously emit light (e.g. at the same time in unison). In some embodiments, each light emitter 204 of each light source 110 may simultaneously emit light (e.g. at the same time in unison).

[0111] In some embodiments, one or more characteristics (such as intensity and / or spectrum, for example) of light emitted by each light source 110 of the lighting system 100 may be simultaneously varied (such as by the controller 150 or the driving circuit 130). In some embodiments, one or more characteristics (such as intensity and / or spectrum, for example) of light emitted by each light emitter 204 of each light source 110 of the lighting system 100 may be simultaneously varied (such as by the controller 150 or the driving circuit 130).

[0112] A light source 110 may be a low-profile light source such that a plurality of light sources 110 may be stacked proximal to the corresponding microplates 112 using a commercially available stacker (such as the stacker 120, for example). As illustrated in Figure 3, a light source 110 may have a height H1 of about 1.8 mm. In some embodiments, a light source 110 may have a height that is less than 2 mm. In some embodiments, a light source 110 has a transverse width that is about 81.2 mm and a longitudinal length that is about 120 mm. In some embodiments, a light source 110 has a spatial footprint that is equal to or smaller than a spatial footprint of a microplate 112.

[0113] High-throughput screening of microorganisms may require consideration of single-well microenvironments and maintenance of consistent growth conditions (e.g. consistent temperature conditions, consistent light intensity and / or consistent wavelength(s) of light) between wells of a microplate and between the microplates themselves. Although LEDs may be more energy efficient than incandescent and fluorescent light emitters, LEDs may also generate heat. Proximity of light emitters 204 (such as LEDs, for example) of a light source 110 to cells in wells of a microplate could produce localized regions of increased or variable temperature. The substrate 202 of a light source 110 may distribute heat across the substrate 202 generated by the light emitters of the light source 110 as described herein to reduce (or eliminate) the occurrence of localized regions of increased or variable temperature.

[0114] Figure 4 is a top plan view illustrating an example embodiment of a supporting frame 114. In Figure 4, longitudinal corresponds to the direction illustrated by the X arrow and transverse corresponds to the direction illustrated by the Y arrow. In the illustrated embodiment of Figure 4, the supporting frame 114 comprises a first longitudinal member 302 and a second longitudinal member 304. A first transverse member 306 is connected to a first end of the first longitudinal member 302 and a first end of the second longitudinal member 304 and extends transversely between the first and second longitudinal members 302 and 304. In some embodiments, the first transverse member 306 is integrally connected to the first end of the first longitudinal member 302 and the first end of the second longitudinal member 304. A second transverse member 308 is connected to a second end of the first longitudinal member 302 and a second end of the second longitudinal member 304 and extends transversely between the first and second longitudinal members 302 and 304. In some embodiments, the second transverse member 308 is integrally connected to the second end of the first longitudinal member 302 and the second end of the second longitudinal member 304.

[0115] The supporting frame 114 may also comprise a first guiding bracket 312 connected to the first longitudinal member 302 and a second guiding bracket 314 connected to the second longitudinal member 304. A light source 110 may be coupled to, or integrated with, the supporting frame 114 by sliding the substrate 202 of the light source 110 through the guiding brackets 312 and 314. When the light source 110 is coupled to the supporting frame 114, a bottom surface of the substrate 202 of the light source 110 may at least partially contact a top surface of the first longitudinal member 302 and / or a top surface of the second longitudinal member 304 and a top surface of the substrate 202 of the light source 110 may at least partially contact an inner surface of the first guiding bracket 312 and an inner surface of the second guiding bracket 314.

[0116] In some embodiments, the supporting frame 114 allows for air-flow across a light source 110 which is coupled to, or integrated with, the supporting frame 114. Such air-flow may at least partially assist with dissipating heat from the substrate 202 of the light source 110. In some embodiments, a cavity 330 of the supporting frame 114 at least partially facilitates air-flow across a light source 110 that is coupled to, or integrated with, the supporting frame 114. Additionally, or alternatively, the supporting frame 114 itself may at least partially dissipate heat from a light source 110 that is coupled to, or integrated with, the supporting frame 114.

[0117] The supporting frame 114 may also comprise one or more projections (or ridges) which extend transversely outwardly from the first longitudinal member 302 and / or the second longitudinal member 304. The one or more projections may simplify placement of the supporting frame 114 (or a light source 110 which is coupled to the supporting frame 114) in a stacker of an incubator (such as the stacker 120, for example). A shape of the one or more projections and / or a placement of the one or more projections relative to the supporting frame 114 may vary depending on an incubation system with which the supporting frame 114 will be used. In the illustrated embodiment of Figure 4, the supporting frame 114 comprises projections 322 and 324 extending transversely outwardly from the first longitudinal member 302 and projections 326 and 328 extending transversely outwardly from the second longitudinal member 304.

[0118] As illustrated in Figure 5, in some embodiments, a supporting frame 114 has a height H2 of about 20 mm. in some embodiments, a supporting frame 114 has a maximum height of about 20 mm. In some embodiments, a supporting frame 114 has a transverse width that is about 89 mm and a longitudinal length that is about 125.5 mm.

[0119] A commercially available stacker may be configured to stack microplates of a specific height. Since a low-profile light source 110 may have a total height that is significantly less than a total height of a microplate 112, positioning the light source 110 directly on the commercially available stacker may position the light source 110 undesirable far away from the microplate 112. As described elsewhere herein, the supporting frame 114 may raise a position of the light source 110 and therefore may at least partially facilitate positioning a low-profile light source 110 proximal to a corresponding microplate 112 (such as proximal to a bottom surface of the corresponding microplate 112, for example).

[0120] In some embodiments, the lighting system 100 comprises at least 50 light sources 110. As described herein, each light source 110 may be operable to illuminate a 384 well microplate. If the lighting system 100 comprises 50 light sources each operable to illuminate a corresponding 384 well microplate, the lighting system may illuminate 19,200 individual microplate wells. In some embodiments, the lighting system 100 comprises less than 50 light sources.

[0121] The lighting system 100 may be integrated into standard laboratory automation infrastructure for microplate-based screening. This may enable users to leverage existing infrastructure and expands the range of assays amenable to microplate formats for the parallel screening of 100s to 10,000s of photosynthetic or photo-responsive microorganisms. Additionally, or alternatively, the lighting system 100 may also be used to extend the throughput of pooled and droplet-based screening paradigms by providing an intermediate throughput for hit validation and may act as a primary screening system for growth optimization and cultivation of distinct genetic clones or strain variants. Additionally, or alternatively, the system could also enable industrial process optimization, the high-throughput study of optogenetics and / or light-driven metabolic activity or genetic circuits in a variety of cyanobacterial, algal, and photo-responsive strains across the tree of life.

[0122] Each light source 110 alone, or in combination with a corresponding supporting frame 114, may have a form-factor or spatial footprint which allows the light source 110 to be used with, or integrated with, commercially available automation infrastructure (such as a commercially available incubator, for example). In some embodiments, each light source 110 alone, or in combination with a corresponding supporting frame 114, has a form-factor that is equal to a standard form-factor defined by the Society for Laboratory Automation and Screening (SLAS). Being able to integrate the lighting system 100 with automation infrastructure may, for example, facilitate high-throughput (e.g., 10s of thousands, 100s of thousands, etc.) microorganism screening and / or growth.

[0123] In some embodiments, the lighting system 100 can withstand humidity up to at least about 85% humidity.

[0124] In some embodiments, one or more components of the lighting system 100 are cleanable with distilled water, 70% ethanol or 70% isopropanol.

[0125] In some embodiments, the lighting system 100 comprises one or more modules. For example, each light source 110 may be, or form, a module. As another example, a plurality of light sources 110 (such as the light sources 110 for a stacker 120) may be, or form, a module. In some embodiments, modules of the lighting system 100 are based on function. A modular design of the lighting system 100 may facilitate rapid scaling up (or scaling down) of the lighting system 100.

[0126] The lighting system 100 may be used in the field of algal research and optogenetics to increase the scale and throughput of experimentation and screening efforts to scales currently limited to heterotrophs, such as yeast, E. coli and human cell cultures. For example, the innate capacity of photosynthetic microorganisms to fix carbon dioxide into biomass may position the photosynthetic microorganisms as promising cell factories for industrial bioproduction with reduced impact on the climate system. In some cases, the lighting system 100 may be used as part of a modular bioreactor system which uses phototrophic microorganisms as microbial cell factories for enhanced carbon capture and production value-added compounds.

[0127] In some cases, the lighting system 100 facilitates consistent growth of both prokaryotic and eukaryotic photosynthetic microorganisms.

[0128] In some cases, the lighting system 100 is integrated into high-throughput screening platforms enabling the screening of photo-responsive organisms, cell lines and assays. The lighting system 100 may facilitate maintaining highly consistent environmental conditions across and between microplates.

[0129] In some cases, the lighting system 100 may facilitate distinction of subtle changes in growth rate, metabolic activity, or assay readout resulting from experimental treatments in high- throughput experiments. Such an experimental design is not possible in either a pooled or droplet-based screening paradigm.

[0130] A series of growth experiments using fast-growing Synechococcus elongatus LITEX 2973 was conducted to identify suitable cultivation conditions for microplate growth using the lighting system 100. For these example experiments, the lighting system 100 comprises light sources 110 which comprise LED light emitters. These experiments explored various LED spectra, use of different seals or lids for microplates during cultivation, positioning of LED arrays in relation to microplates, and selection of microplate types for cultivation and screening. These experiments were designed to identify cultivation conditions minimizing variability in growth rate and photopigment production across a microplate. Photopigment production in cyanobacteria, including light-harvesting pigments and photoprotective carotenoids, may be highly dependent on light intensity and may be associated with metabolic state. Observing pigment production through absorption measurements at photopigment absorbance peaks, in addition to growth rate, may provide insight into metabolism and light exposure across the microplate.

[0131] Light spectrum may have a significant impact on photosynthetic efficiency, photopigment biosynthesis, and growth rates in photosynthetic microorganisms. This may be a result of the varying absorption peaks of individual photopigments, including chlorophylls (430-475 nm and 630-700 nm), phycobilins (500-675 nm), and carotenoids (400-500 nm) that comprise photosynthetic light harvesting complexes. The photosynthetic complexes of different microorganisms can be structured to more efficiently harvest certain wavelengths of light and genetic regulatory mechanisms can drive photopigment production in response to specific light spectra. Cool white phosphor-converted-LEDs may support growth by emitting broad spectrum photosynthetically active radiation (PAR), with emission peaks mirroring photopigment absorption peaks. Based on this, light sources 110 comprising broad-spectrum phosphor- converted-LED light emitters were initially used with colour temperatures of 4044 K, 5091 K and 6083 K. Collected emission spectra indicated 5091 K LEDs provided the most even light distribution across key photosynthetically active wavelengths. A cultivation experiment was also performed to investigate the impact of LED spectra on S. elongatus UTEX 2973 growth. S. elongatus UTEX 2973 pre-cultures in Erlenmeyer flasks were incubated for one week under each of the three LED spectra (e.g. 4044 K, 5091 K and 6083 K) in isolation. Cultures were then transferred to a 384-well microplate for cultivation under the cognate LED spectra. Light sources 110 comprising 5000K LEDs led to the highest median growth over a 3-day cultivation experiment. An even emission spectrum and increased growth of S. elongatus UTEX 2973 led to the selection of light sources 110 comprising 5091 K LEDs for downstream experiments. Specific microorganism strains and / or screening paradigms may benefit from alternative LED spectra.

[0132] Although a faster median growth rate was observed using light sources 110 comprising 5091 K spectrum LEDs, significant variability in optical density across all microplates was also noticed, with the outside wells evaporating quickly resulting in significantly decreased growth. Such edge-effects may be common in high-throughput screening often resulting from variability in gas exchange, humidity, or temperature across the plate. To mitigate the impact of these effects, growth was compared of S. elongatus UTEX 2973 in microplates with one of two breathable seals (e.g. AeraSeal™ (Excel Scientific™, USA) and Breathe-Easy™ (Diversified Biotech, USA)) or transparent microplate lids. Light sources 110 were positioned beneath the microplates when sealed with translucent or opaque seals and positioned above the microplates with a transparent lid to minimize condensation. Results showed a significantly higher growth in the microplate sealed with the AeraSeal™ seal, which is an opaque woven-rayon seal with high- breathability. As the AeraSeal™ seal may not be amenable to automated microplate sealing and pealing infrastructure, downstream experimentation used PermASeal™ (ITS Scientific™, UK), a woven paper-based seal that showed a comparable increase in growth. The PermASeal™ seal may be amenable to the Agilent PlateLoc Thermal Microplate Sealer (Agilent™, USA) incorporated into the automation infrastructure used in system testing. Alternative woven breathable seals may be used depending on available instrumentation. The significant variability in growth based on seal selection indicates the importance of considering gas exchange in relation to photosynthetic growth and the design of high-throughput lighting systems.

[0133] These experiments also suggested that evaporation rates may be an important consideration when selecting microplate seals. To explore this, experiments were conducted to measure the rate of evaporation from 384-well microplates. In these experiments 384-well plates were loaded with S. elongatus UTEX 2973 culture or BG-11 medium and sealed with either the AeraSeal™, Breathe-Easy™, or PermASeal™ seals, or with a transparent microplate lid. Plates were then loaded into a 5 C450 incubator and well volumes were measured every 24 hours for 4 days using an Echo 525 acoustic liquid handling system. Results indicated that wells may lose approximately 56.7 iL their volume after 96 hours, using breathable PermASeal™ seals, which is the highest evaporation rate of any seal types, but with less across-plate variability than microplate lids or Breathe-Easy™ rayon seals. Significant differences in evaporation were observed across plates sections for most seal types after 96 hours (PermASeal™: F(7,376) = 2.78, p = 0.00788, Cohen's f = 0.23; AeraSeal™: F(7,376) = 7.61, p = 1.35x10A-8, Cohen's f = 0.38; Nunc Lid: F(7,376) = 15.97, p < 2x10A-16, Cohen's f = 0.55), with Breathe-Easy™ seals showing marginally significant differences (F(7,376) = 1.97, p = 0.0584, Cohen's f = 0.19). Although differences were observed, the effect sizes suggest PermASeal™ and Breathe-Easy™ seals demonstrate a relatively low level of variations between plate sections. These differences may highlight the importance of seal type in controlling evaporation rates, with experimental durations potentially limited to 72-96 hours depending on incubator temperature and humidity control.

[0134] The selection of opaque woven seals for microplate sealing during cultivation experiments may necessitate the placement of light sources 110 below microplates thereby illuminating cultures through clear well bottoms. Each light source 110 and supporting frame (or structure) 114 was then positioned in place of a microplate directly below the cultivation microplate in a Cytomat 5 C450 incubator rack. This example configuration permitted a maximum height of 20 mm of the light source 110 and supporting frame 114 while still accommodating automated plate retrieval. This maximum height means that the light source 110 may be positioned between about 3 mm and about 20 mm from the bottom of the corresponding microplate. As a result of the conical shape of LED light emission from a LED light emitter, placement of LED light emitters of a light source 110 as close to the base (or bottom) of the corresponding microplate as possible may result in the most even light intensity across the microplate.

[0135] In some embodiments, minimizing the distance between the light emitters 204 of a light source 110 and the corresponding microplate 112 reduced variability in light intensity across the dimensions of the corresponding microplate 112. In some embodiments, a distance between a light emitter 204 and a corresponding well of a microplate 112 that the light emitter 204 is operable to illuminate is minimized.

[0136] First Example Case

[0137] In a first example case, S. elongatus UTEX 2973 was cultivated in three transparent (clear) and three opaque (black) microplates in parallel using the lighting system 100. As illustrated in Fig. 6A, in such example case, S. elongatus UTEX 2973 growth (OD750) and growth rates (p) in clear and black plates varied significantly in early timepoints before converging after 72 hours. Although final biomass accumulation (OD750) was comparable, with the median OD750 values in black plates 1.14 X that of clear plates, growth rates lagged in black plates over the first 24 hours with a median growth rate across 1152 wells of -0.005 p[h'1] (sd = 0.003p [h1]) at 24 hours, indicating no growth. Median growth rates in black plates then increased rapidly between 24 and 72 hours, reaching a maximum of 0.047 p[tr1] (sd = 0.011 p[h-1]) at 72 hours before quickly decreasing to 0.0167 p [IT1] (sd = 0.012 p [IT1]) at 96 hours. In comparison, median growth rates in clear plates showed less temporal variability, with a gradual decrease in growth rate over the 8-day cultivation experiment, from a maximum median growth rate of 0.018 p[tr1] (sd = 0.005 p[h1]) at 24 hours to a minimum of 0.008 p [IT1] (sd = 0.005 p[h1]) at 196 hours (final timepoint). The maximum growth rate 0.047 p[tr1] observed in black plates at 72 hours was near a model predicted rate in Synechocystis sp. PCC 6803 of 0.053 p[h'1] at 100 pmol / m2 / s, but well under the reported S. elongatus UTEX 2973 growth rate of 0.151 p[tr1] at 30°C, albeit with CO2 supplementation (3%) and an increased light intensity (300 pmol / m2 / s). Although growth rate in black plates increased rapidly afterwards, this delay in growth may suggest the need for S. elongatus UTEX 2973 to adapt to conditions in black plates, possibly indicating decreased light intensity.

[0138] In the first example case, to visualize variability in growth (OD750) across individual microplates, wells were divided into plate sections based on position (see Figure 6B). Results indicated some temporal variability in growth across both plate types, with growth lagging slightly in early timepoints in sections 1-3, representing the three outside rows of a 384-well plate. By Timepoint 4 (T4 I 96 hours), only black plate section 1, representing the outside row of wells, showed a significantly decreased growth (see Figures 6C and 6D). This decrease was less pronounced in clear plates and was not statistically significant by 96 hours. However, more high outliers were observed in clear plates, indicating some stochasticity in well-to-well growth rates (see Figure 6C).

[0139] In the first example case, relative chlorophyll a (444 nm), carotenoid (495 nm) and phycocyanin (634 nm) absorbance was also significantly lower in black-well plates, suggesting a lower light intensity across the plate (see Figure 6E). Photopigment absorbance trends were, however, consistent between triplicates of each plate type (see Figure 6E). Black plates also showed significant differences between relative photopigment absorbance in section 1 and that in sections 2-8 throughout the 8-day experiment (see Figure 6F). By 96 hours, clear plates showed no significant differences in relative photopigment production across plate sections (see Figure 6F). The difference in relative photopigment abundance between plate types can likely be explained by refraction and internal reflection of light throughout clear-well microplates and into the light emitters (such as LEDs, for example) of the light sources 110 of the lighting system 100, potentially resulting in localized variability in light intensity. These phenomena could also explain the increased growth rate in the outside row of clear plates (section 1) and increased variability in growth rate across clear plates. Combined, these results indicate that either clearwell or black-well microplates can be used with the lighting system 100. Users may consider that edge-effects may be more pronounced in black-well microplates and growth rate stochasticity may be more prominent when using a clear-well microplate. Plate type selection may therefore be dependent on experimental design parameters and screening paradigm.

[0140] A microorganism hourly growth rate ( .[h1]) may be calculated using the following formula: where OD and t represent OD750 values and time in hours, respectively, at consecutive timepoints n and n-1. In such circumstances, i[h1] may equal the relative increase in OD750 per hour between two timepoints. Second Example Case - High-throughput medium composition and antibiotic sensitivity screening

[0141] In a second example case, to demonstrate one or more capabilities of the lighting system 100, high-throughput screening experiments were initially designed to evaluate medium composition and antibiotic treatment on S. elongatus LITEX 2973 growth. A black microplate was selected for both experiments, as the 308 wells in sections 2-8 (excluding outside row of wells) enables the testing of 4 conditions at 11 concentrations and with 7 replicates per concentration. With conditions randomly distributed across two microplates, the impact of individually varying the concentration of each of the 8 components of BG-11 medium was evaluated. Cells were washed twice with distilled water prior to dispensing into microplates. The results indicated that the concentrations of K2HPO4, NaHCOs, NaNOs, MgSC and trace elements have the most significant impact on S. elongatus LITEX 2973 growth rates, with phosphorus (K2HPO4), inorganic carbon (NaHCCh) and nitrogen (NaNCh) potentially being limiting at a standard BG-11 composition (see Figures 7A and 7B). In the second example case, antibiotic experiments showed S. elongatus LITEX 2973 sensitivity across all tested antibiotics, with streptomycin and carbenicillin exhibiting antibacterial activity at the lowest concentrations (see Figures 70 and 7D). The results of the second example case conform to expected values, indicating that the lighting system 100 may have capability for both reproducibility and the identification of phenotypes consistent with commonly used cultivation formats. Based on this consistency, some medium composition experiments were extended using response surface modelling (RSM) to design optimized medium compositions and screened a library of bioactive small molecules for increased biomass production. These validation steps may be directly related to bioproduction potential and therefore may highlight the power of the lighting system 100 to identify factors that increase biomass production using chemical genetic approaches.

[0142] Example 3 - High-throughput medium optimization

[0143] In a third example case, to demonstrate cross-strain compatibility, an optimization experiment was performed with the objective of strain-specific BG-11 medium optimization. Synechococcus elongatus LITEX 2973, Chlamydomonas reinhardtii LITEX 90 and Nostoc hatei CUBC1040 were selected, as they span cyanobacterial and eukaryotic photosynthetic microorganisms, including both unicellular and filamentous strains. These optimization experiments enabled identification of limiting nutrients for each strain, as well as optimized medium compositions for increased growth under defined conditions. Parallel cross-strain medium optimization also served as a demonstration of the lighting system 100 in a high-throughput screening paradigm relevant to development of industrial bioprocesses. Response surface modelling (RSM) may support determination of optimal settings of inputs to maximize, minimize or target a specific output. In the context of medium optimization experiments, RSM facilitated the simultaneous identification of factors with the most significant impact on growth rate, including limiting and excess nutrients, and optimization of inputs to maximize biomass production, including evaluation of the relationship between concentrations of multiple inputs.

[0144] In the third example case, a central composite design, or Box-Wilson design, was used for RSM of strain-specific BG-11 medium optimization. This design strategy defined three levels of each factor, including a center point (0), a low value (-1) and a high value (1). As atmospheric carbon capture may be a desired objective of industrial application of photosynthetic microorganisms, optimization was performed at fixed NaHCO3concentrations. These were set at either 0 g / L NaHCO3, making strains entirely dependent on atmospheric CO2, or the standard BG-11 concentration of 0.42 g / L NaHCO3. This resulted in an example eight-factor BG-11 optimization which required a minimum of 51 conditions. A single 384-well plate may support an experiment with 61 conditions, including 24 replicates of the center condition (0 value for all factors) and 6 replicates of the 60 additional conditions. In the third example case, factor levels were defined using the standard BG-11 composition as a center point (see Table 1).

[0145] Table 1

[0146] Table 1 is a table showing BG11 composition optimization factor levels for central composite design and response surface modeling. In the third example case, a single round of lighting system growth optimization was performed with the lighting system 100 prior to flask-based testing (see Figure 8B). Results of the third example case indicate that nitrogen content (NaNCh) was the factor with the most significant impact on growth rate of both S. elongatus LITEX 2973 and C. reinhardtii LITEX 90, regardless of NaHCOs concentration (see Figure 8B). MgSCU, K2HPO4, and CaCh were also important factors across both strains (see Figure 8B). In this example case, MgSC t was the most important factor in Nostoc hatei CUBC1040 growth rate, with NaNCh content being the fourth or fifth most important factor (see Figure 8B). This result is consistent with expectations as Nostoc hatei CUBC1040 is heterocystous and capable of fixing atmospheric N2. These trends can be visualized by observing the OD750 values of individual cultures in relationship to the depletion status of a given nutrient. Results support model predictions, suggesting that S. elongatus LITEX 2973 and C. reinhardtii LITEX 90 are very sensitive to depletion of NaNCh, MgSCU, and K2HPO4, whereas Nostoc hatei CUBC1040 only shows this degree of sensitivity to MgSC>4 depletion.

[0147] For the third example case, response surface models for each strain indicated that increasing NaNOs concentrations to the highest tested concentration would maximize growth rates consistent with previous observations (see Figure 8A). Rather than increasing nutrient provision to all cultures, RSM was leveraged to design optimal medium composition with a defined NaNOs concentration of 3.0 g / L, which is that of standard BG-11 medium (see Table 2). The results indicated that variations in the concentrations of K2HPO4, MgSCU, CaCh citrate and trace elements all contributed to optimized growth in microplates. EDTA, a chelating agent, supported growth in the absence of NaHCCh, but decreased growth in the presence of NaHCCh. EDTA is a known inhibitor of carbonic anhydrases (CAs) through chelation of the Zn2+cofactor in the active site of many microalgal CAs. This could interfere with the conversion of HCCh' to CO2 in the carboxysome for fixation by ribulose-1 ,5-bisphosphate carboxylase / oxygenase (RuBisCo). Na2CC>3 concentrations may be decreased to maximize growth in all cases except S. elongatus LITEX 2973, in the absence of alternative inorganic carbon supplementation.

[0148] Table 2

[0149] Table 2 shows optimized BG11 medium compositions for each strain and inorganic carbon supplementation condition. For Table 2, NaNCh compositions were set to standard BG11 concentrations. In Table 2, values range from -1 to 1. Predicted OD750 values in Table 2 are based on response surface modelling through JMP interface.

[0150] In the third example case, validation experiments in flasks were performed for medium compositions containing NaHCOs at standard BG-11 concentrations across all three microalgal strains, as well as in S elongatus LITEX 2973 in NaHCOs-deficient medium. Cultures were inoculated in Erlenmeyer flasks in triplicate in standard and optimized BG-11 medium. OD750 values were collected at days 1, 3, and 7 and biomass dry weight was collected at day 7 to evaluate final impact of optimized medium on biomass accumulation. These results indicated a 38.4% to 61.6% increase in total biomass accumulation (dry weight) over 7 days of cultivation (see Figure 8C). These results of the validation experiments are consistent with findings in microplates and further demonstrate the power of the lighting system 100 to optimize growth conditions prior to scale-up. Indeed, if scalable, the biomass increases observed using optimized media could lead to 10,000s tonnes of additional CO2 fixation and positively impact economic feasibility of algae-based carbon capture strategies without the need for metabolic engineering. Example 4 - Bioactive molecule screening

[0151] In a fourth example case, bioactive molecule screening was performed using the lighting system 100 in three rounds, prior to the selection of candidate compounds for downstream characterization. The primary screen (round 1) involved a single replicate of all 4240 bioactive molecules in the composite library at 5 .M, in 14 clear 384-well microplates. These microplates were screened in 2 sets of 9 and 5, respectively. Although the median OD750 value at the final timepoint varied between Set 1 and Set 2 (see Figure 9A), values were normalized by calculating Z-scores on a plate-by-plate basis (see Figure 9B). The use of Z-scores for outlier detection assumes a normal distribution of data. Skewness and kurtosis tests gave values of - 0.01 and 8.61 , respectively, indicating very little skew across the entire dataset and a sharper central peak than that of a standard normal distribution (see Figure 9B). This results from most cultures growing at near the mean rate, with a relatively small number of significant outliers. The negative skew of the OD750 and Z-score values in Set 2 likely resulted from increased separation between median growth rates of cultures that continued to grow and those treated with compounds that prevented growth. Hits were selected based on a Z-score > 2.5 or < -2.5, for “High” and “Low” OD750 hits, respectively (see Figure 9B and Table 3). This resulted in the selection of 59 high-OD7so hits (top 1.4% of values) and 87 I0W-OD750 hits (bottom 2.1% of values).

[0152] Table 3

[0153] Table 3 shows a tally of hits from round 1 of bioactive screen in Synechococcus elongatus UTEX2973 of the fourth example case.

[0154] The 146 hits selected in the round 1 screen were rescreened in triplicate in round 2 across three identical 384-well plates (see Figure 9C). Each replicate plate included 132 negative control wells (0.1% DMSO). Interestingly, control data in round 2 did not show the same slight negative skew as round 1 data. Skewness and kurtosis tests gave values of 1.29 and 6.09, respectively, indicating a positive skew and a sharper central peak than that of a standard normal distribution (see Figure 9D). This positive skew can also be explained by observed growth dynamics in clear 384-well plates, where low values are bound by the minimum value of no growth and high- values can vary significantly (see Figure 9D). Based on these observations, outliers for future screening were selected by calculating p-values for each experimental OD750 measurement. Compounds were then filtered to those that had p-values < 0.1 , indicating less than a 10% change of this value occurring randomly, in at least 2 of 3 replicates. This selection criterion accounted for observed stochasticity in high OD750 values in clear-well plates, as the probability that the same compound is the subject of a randomly occurring high OD750 value multiple times is low. A total of 64 I0W-OD750 outliers and 6 high-OD7so outliers matched this criterion. All 6 high- OD750 outliers were selected for downstream characterization. Eight of the 64 I0W-OD750 outliers were also selected by maximizing the difference between the mean of the negative control data and the mean of the 3 experimental replicates (see Table 4). L0W-OD750 hits were clearly distinguished from negative controls, whereas high-OD7so hits appeared at the upper end of the distribution for negative controls (see Figure 9D). Table 4 Table 4 shows selected hits from round 2 of bioactive screen. In Table 4, the “Significant Measurements” column indicates number or replicates with p-value < 0.1.

[0155] The 6 high-ODyso and 7 I0W-OD750 hits selected from round 2 were subsequently tested over a narrow concentration gradient (1.667 .M, 3.333 .M, 5 iM and 6.667 .M). This gradient provided additional replication and preliminary insight into dose-dependence of observed growth effects (see Figures 9E and 9F). High-ODyso candidate compounds were selected if at least 3 treatments showed higher OD750 values than the negative control. Based on the results, all high- ODyso candidate compounds were selected for further characterization with the exception of methyl 7-deshydroxypyrogallin-4-carboxylate. Cyanocidal compounds may have application in the mitigation of harmful algal blooms in the aquaculture industry and environmental settings. Although the identification of cyanocidal compounds was not the primary objective of this screen of the fourth example case, gentian violet and disulfiram were selected for further characterization. Gentian violet and disulfiram showed the most significant response at the lowest tested concentration of 1.667 .M, outside of organomercury compounds thimerosal and phenylmercuric acid. Both thimerosal and phenylmercuric acid contain a covalently bound atom of mercury (Hg). These compounds were not selected because, at tested concentrations of 1.667 .M, this results in a Hg concentration of 0.334 mg / L, which is, for example, 334 times the maximum acceptable concentration in drinking water according to the Government of Canada. Although gentian violet has been shown to persist in certain environments, it is amenable to bioremediation by some species of bacteria, fungi and algae. Less is known about the environmental stability of disulfiram, which is a drug used to treat alcohol dependence and has been proposed as a narrow-spectrum antibiotic. However, other compounds containing disulfide bonds may be cleaved in reductive environments, such as freshwater and marine sediments, indicating a possible bioremediation route. The resulting set of 7 candidate compounds were sourced in larger quantities for additional testing. Each compound was tested at 12 concentrations, from 0.1 iM to 15 piM, with 8 to 12 replicates at each concentration. Both gentian violet and disulfiram significantly decreased growth at concentrations of 2 iM and above (see Figure 9G). However, only gossypetin among the high-ODyso candidates resulted in a significant growth phenotype (see Figure 9G).

[0156] In the fourth example case, the impact of gossypetin on growth was further explored up to 100 iM in microplate format, with 12 replicates at each concentration. Results indicated a significant increase in OD750 above 6 .M (p < 0.05), with a maximum increase in OD750 between 20 iM to 50 .M. A 1.4-fold median increase was observed at 20 iM gossypetin (see Figures 9H and 9I). A distinctive phenotype observed when treating S. elongatus LITEX 2973 with gossypetin was a visible colour change of the culture from green to near-black, despite gossypetin having a yellow colour when dissolved in DMSO. This colour change was observed in BG-11 medium, as well as the S. elongatus LITEX 2973 culture, but not in distilled water, and is likely the result of iron- mediated oxidation and complexation resulting in colour changes in other flavonoids. An absorbance scan indicated that gossypetin treatment leads to an absorbance peak at 370 nm in BG-11 medium, S. elongatus LITEX 2973 culture, and dH2O, with an increase in absorption across the visible spectrum observed only in BG-11 medium and S. elongatus LITEX 2973 culture. A slight increase in absorbance was also observed at OD750, but this is insufficient to explain the increase in measured OD750 during the time course of the growth experiment.

[0157] Gossypetin is a flavonol from a class of flavonoids that was initially isolated from Hibiscus sabdariffa. Flavonoids are widespread in plants and plant products, and are often considered antioxidants with the potential to scavenge reactive oxygen species (ROS) and protect from ROS-induced DNA damage and cellular stress. Gossypetin has been shown to reduce X- radiation induced DNA damage, as well as display anti-atherosclerotic effects and anti-cancer effects, as well as lead to the induction of Ap plaque phagocytosis, in the context of Alzheimer’s disease. Interestingly, gossypetin and related flavonols have also been observed to have antimicrobial effects. However, gram-negative prokaryotes, such as cyanobacteria, may be less susceptible to this class of compounds. Another flavonoid, naringenin, has also been reported to increase growth rate, chlorophyll production and membrane permeability in several cyanobacterial. The observed absorbance peak of gossypetin-treated cultures and medium in the LIV range suggests a photoprotective mechanism of action, in addition to possible antioxidant effects, and impacts on membrane permeability. A 50 mL flask-based cultivation experiment was used to determine whether the impact of gossypetin on Synechococcus elongatus LITEX 2973 growth could scale to larger culture volumes. Cultures were inoculated in Erlenmeyer flasks in triplicate, in standard BG-11 medium, with 10 iM and 20 iM gossypetin treatments and untreated. OD750 values and absorbance scans were collected at days 1, 3, and 7, and biomass dry weight was collected at day 7 to evaluate final impact of gossypetin on biomass accumulation. These results (see Figure 9J) indicated a 16.5% and 68.0% increase in total biomass accumulation over 7 days of cultivation at 10 iM and 20 iM gossypetin, respectively, consistent with microplate results. It will be appreciated by those skilled in the art that changes could be made to the various aspects of the subject application described above without departing from the inventive concept thereof. It is to be understood, therefore, that this subject application is not limited to the particular aspects disclosed, but it is intended to cover modifications as defined by the appended claims.

[0158] When introducing elements of the present invention or the embodiments thereof, the articles “a,” “an,” “the,” and “said” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed element.

Claims

CLAIMS:

1. A lighting system for illuminating a plurality of microplates, the lighting system comprising: a plurality of light sources, each light source of the plurality of light sources operable to illuminate a corresponding microplate of the plurality of microplates, the plurality of light sources alternatingly stackable with the plurality of microplates.

2. The lighting system of claim 1 , wherein each light source of the plurality of light sources is operable to simultaneously illuminate the corresponding microplate of the plurality of microplates.

3. The lighting system of claim 1 or 2, wherein each light source of the plurality of light sources is operable to consistently illuminate the corresponding microplate of the plurality of microplates.

4. The lighting system of claim 3, wherein each light source of the plurality of light sources is operable to emit light of equal intensity.

5. The lighting system of claim 3 or 4, wherein each light source of the plurality of light sources is operable to emit an equal spectrum of light.

6. The lighting system of any one of claims 1 to 5, wherein each light source of the plurality of light sources comprises: a substrate; and a plurality of light emitters supported by the substrate.

7. The lighting system of claim 6, wherein the plurality of light emitters are arranged on the substrate in a grid comprising a plurality of rows and a plurality of columns.

8. The lighting system of claim 6 or 7, wherein a spacing between adjacent ones of the plurality of light emitters is equal.

9. The lighting system of any one of claims 6 to 8, wherein each of the plurality of light emitters is the same.

10. The lighting system of any one of claims 6 to 9, wherein each light emitter of the plurality of light emitters is individually controllable.

11. The lighting system of any one of claims 6 to 10, wherein a wavelength of light emitted by each light emitter of the plurality of light emitters is variable.

12. The lighting system of any one of claims 6 to 11, wherein an intensity of light emitted by each light emitter of the plurality of light emitters is variable.

13. The lighting system of any one of claims 6 to 12, wherein the plurality of light emitters comprises a plurality of light emitting diodes (LEDs).

14. The lighting system of any one of claims 6 to 13, wherein the plurality of light emitters emit light having a wavelength in a range from about 400 nm to about 750 nm.

15. The lighting system of any one of claims 6 to 14, wherein the plurality of light emitters comprises at least 384 light emitters.

16. The lighting system of any one of claims 6 to 15, wherein the substrate distributes heat across the substrate and away from the plurality of light emitters.

17. The lighting system of any one of claims 6 to 16, wherein the substrate distributes heat evenly across the substrate.

18. The lighting system of any one of claims 6 to 17, wherein the substrate comprises a superconducting aluminum plate.

19. The lighting system of any one of claims 1 to 18, wherein each light source of the plurality of light sources has a height that is less than 2 mm.

20. The lighting system of any one of claims 1 to 19, wherein the plurality of light sources comprises at least 50 light sources.

21. The lighting system of any one of claims 1 to 20, further comprising a plurality of supporting frames, each supporting frame configured to support a corresponding light source of the plurality of light sources.

22. The lighting system of claim 21 , wherein the plurality of supporting frames is alternatingly stackable with the plurality of microplates.

23. A method for illuminating microorganisms in a plurality of microplates, the method comprising: alternatingly stacking a plurality of light sources and the plurality of microplates; and illuminating each microplate of the plurality of microplates with a corresponding light source of the plurality of light sources.

24. The method of claim 23, wherein alternatingly stacking the plurality of light sources and the plurality of microplates comprises positioning each microplate of the plurality of microplates above the corresponding light source of the plurality of light sources.

25. The method of claim 23, wherein alternatingly stacking the plurality of light sources and the plurality of microplates comprises positioning each microplate of the plurality of microplates below the corresponding light source of the plurality of light sources.

26. The method of any one of claims 23 to 25, wherein illuminating each microplate of the plurality of microplates comprises illuminating each microplate of the plurality of microplates with light of equal intensity.

27. The method of any one of claims 23 to 26, wherein illuminating each microplate of the plurality of microplates comprises illuminating each microplate of the plurality of microplates with an equal spectrum of light.

28. The method of any one of claims 23 to 27, further comprising supporting each of the light sources of the plurality of light sources with a corresponding supporting frame to position eachlight source of the plurality of light sources closer to the corresponding microplate of the plurality of microplates.

29. The method of any one of claims 23 to 28, further comprising simultaneously varying an intensity of light emitted by each light source of the plurality of light sources.

30. The method of any one of claims 23 to 29, further comprising simultaneously varying a spectrum of light emitted by each light source of the plurality of light sources.

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