Method for recovering biomass including poly-4-hydroxybutyrate

Abstract

The present invention relates to a method for recovering a biomass including poly-4-hydroxybutyrate, the method comprising: (1) a step for forming a product including poly-4-hydroxybutyrate (P4HB) biomass aggregates by introducing a polymer coagulant to a culture medium; (2) a step for separating the P4HB biomass aggregates from the product; (3) a step for coating the separated P4HB biomass aggregates with a flow promoter; and (4) a step for drying the separated P4HB biomass aggregates.

Description

Method for recovering biomass containing poly-4-hydroxybutyrate

[0001] The present invention relates to a method for efficiently recovering biomass containing poly-4-hydroxybutyrate from a culture medium (fermentation culture medium).

[0002] Bioproduction processes utilizing renewable carbon sources are attracting attention as a solution to overcome the limitations of petrochemical-based processes, such as petroleum resource depletion, rising energy prices, and environmental issues. Among the compounds that can be produced through these bioproduction processes, commercially available compounds include gamma-butyrolactone (GBL) and 1,4-butanediol (BDO). GBL is used as a solvent in electronics and lubricant extraction, and as an intermediate for the synthesis of various compounds.

[0003] Meanwhile, US 9,084,467 B2 discloses a method for producing poly-4-hydroxybutyrate (P4HB) from microorganisms using a renewable carbon source, and converting and producing gamma-butyrolactone (GBL) by heating the biomass containing the P4HB with a catalyst. However, US 9,084,467 B2 does not disclose a process for efficiently recovering the biomass containing P4HB from the culture medium.

[0004] As a method of recovering biomass containing P4HB from the above-mentioned culture solution, a method of crushing biomass cells containing P4HB, mechanically separating them, and then filter-pressing the obtained P4HB biomass aggregates through a process of coagulation is applied. However, the P4HB biomass aggregates are very small, on the order of 2 to 15 ㎛ in size, so there is a problem of significant loss of P4HB biomass aggregates during the filter-pressing process. In addition, even if the P4HB biomass aggregates are concentrated, solvent removal is not sufficient, so additional drying equipment is required, and when drying is performed at a high temperature, P4HB, which has a melting temperature of about 75 ℃, melts, which may cause losses and damage to the equipment.

[0005] Therefore, there is a need for a technology that can efficiently recover biomass containing P4HB from culture medium.

[0006] In order to solve the above-mentioned conventional problem, the object of the present invention is to provide a recovery method capable of recovering biomass containing poly-4-hydroxybutyrate (P4HB) at a high yield by improving the recovery process (process) of biomass containing P4HB from a culture solution.

[0007] In addition, another object of the present invention is to provide a biomass containing P4HB obtained from the above recovery method and a method for producing a compound using the biomass.

[0008] In order to achieve the above object, the present invention provides a method for recovering biomass containing poly-4-hydroxybutyrate, comprising the steps of: (1) forming a product containing poly-4-hydroxybutyrate (P4HB) biomass aggregates by adding a polymer flocculant to a culture solution; (2) separating the P4HB biomass aggregates from the product; (3) coating the separated P4HB biomass aggregates with a flow promoter; and (4) drying the coated P4HB biomass aggregates.

[0009] In one embodiment, the polymer coagulant may comprise a cationic polymer coagulant having a molecular weight of 1,000,000 Da or greater.

[0010] According to another embodiment, the content of the cationic polymer coagulant may be 0.01 to 10 wt% based on the total weight of the polymer coagulant.

[0011] According to another embodiment, the cationic polymer coagulant may include at least one selected from the group consisting of acrylamide-based polymers, acryloyl-based polymers, amidine-based polymers, polyvinylamine-based polymers, diallyldimethylammonium chloride (DADMAC)-based polymers, and polyamine-based polymers.

[0012] According to another embodiment, the average particle size of the P4HB biomass aggregates included in the product may be 2 mm or more.

[0013] According to another embodiment, the separation in step (2) may be performed by at least one selected from the group consisting of a press and an electro-osmotic dehydrator.

[0014] According to another embodiment, the step (2) may include the steps of (2-1) introducing the product into a press and first dehydrating to obtain a P4HB biomass aggregate cake; and (2-2) introducing the P4HB biomass aggregate cake into an electroosmotic dehydrator and secondarily dehydrating to obtain the P4HB biomass aggregate.

[0015] According to another embodiment, the operating pressure of the press may be 0.01 to 1 MPa.

[0016] According to another embodiment, the electroosmotic dehydrator may have an operating speed of 0.1 to 4 m / min and an applied voltage of 10 to 150 V.

[0017] In another embodiment, the flow promoter may comprise a metal salt.

[0018] According to another embodiment, the metal salt may include at least one selected from the group consisting of ferric sulfate, ferrous sulfate, ferric chloride, ferric chloride, calcium chloride, calcium carbonate, calcium hydroxide, calcium sulfate, magnesium sulfate, magnesium chloride, and magnesium carbonate.

[0019] According to another embodiment, the coating content of the fluidity accelerator may be 0.1 to 20 wt% based on the total weight of the P4HB biomass aggregate separated in step (2).

[0020] According to another embodiment, the drying in step (4) may be performed using a natural wind dryer.

[0021] According to another embodiment, the natural wind dryer has an air temperature of 30 to 90°C and an air pressure of 0.1 to 10 kgf / cm. 2 , the air flow rate can be 0.1 to 30 L / min, and the belt speed can be 0.05 to 3 m / min.

[0022] According to another embodiment, the method for recovering biomass comprising poly-4-hydroxybutyrate may have a yield of P4HB biomass of 80% or more.

[0023] Meanwhile, the present invention provides a biomass containing poly-4-hydroxybutyrate obtained from a method for recovering biomass containing the poly-4-hydroxybutyrate.

[0024] In addition, the present invention provides a method for producing a compound, which comprises a step of processing biomass containing poly-4-hydroxybutyrate obtained from the above recovery method.

[0025] According to one embodiment, the compound may be a raw material compound comprising at least one of gamma-butyrolactone (GBL), 1,4-butanediol (BDO), tetrahydrofuran (THF), and 2-pyrrolidinone, a derivative of the raw material compound, or a polymer using the raw material compound.

[0026] The method for recovering biomass containing poly-4-hydroxybutyrate (P4HB) according to the present invention is simpler than conventional recovery methods (e.g., a method of crushing P4HB-containing biomass cells, mechanically separating them, and then filter-pressing the obtained P4HB biomass aggregates through a process of coagulation), and thus, biomass containing P4HB can be efficiently recovered from a culture medium. In particular, considering the physical properties of P4HB (e.g., Tm of 75°C), biomass containing P4HB can be recovered stably and with a high yield even without using a high-temperature heat source.

[0027] In addition, by coating the biomass with a flow promoter during the recovery process of biomass containing poly-4-hydroxybutyrate (P4HB), the flow of the biomass inside the reactor can be efficiently achieved during the subsequent process of converting and producing compounds such as gamma-butyrolactone (GBL) by heating the biomass containing P4HB with a catalyst.

[0028] Therefore, the present invention can contribute to efficiently producing useful compounds such as gamma-butyrolactone (GBL) and 1,4-butanediol (BDO) using biomass containing P4HB obtained from the above recovery method.

[0029] Figure 1 is a flow chart showing the process of a method for recovering biomass containing poly-4-hydroxybutyrate according to one embodiment of the present invention.

[0030] Hereinafter, the present invention will be described in detail. However, the present invention is not limited to the contents disclosed below, and may be modified in various forms as long as the gist of the invention is not changed.

[0031] The word "comprising" or "including" in this specification is intended to specify particular features, regions, steps, processes, elements and / or components, and does not exclude the presence or addition of other features, regions, steps, processes, elements and / or components, unless specifically stated to the contrary.

[0032] All numbers and expressions indicating the amounts of components, reaction conditions, etc. described in this specification are to be understood as being modified by the term “about” in all cases unless otherwise specified.

[0033]

[0034] Method for recovering biomass containing poly-4-hydroxybutyrate

[0035] The method for recovering biomass containing poly-4-hydroxybutyrate according to the present invention comprises adding a specific coagulant to a culture medium (fermentation culture medium) to coagulate biomass containing poly-4-hydroxybutyrate (hereinafter referred to as 'P4HB') contained in the culture medium into relatively large particles, and optimizing the process of removing impurities and drying, thereby minimizing loss of biomass during the process of recovering the biomass and achieving process simplification.

[0036] Specifically, the recovery method including P4HB according to the present invention comprises the steps of (1) adding a polymer flocculant to a culture medium to form a product including poly-4-hydroxybutyrate (P4HB) biomass aggregates; (2) separating the P4HB biomass aggregates from the product; (3) coating the separated P4HB biomass aggregates with a flow promoter; and (4) drying the coated P4HB biomass aggregates, which will be described in detail with reference to FIG. 1 as follows.

[0037]

[0038] Step (1): Formation of products containing P4HB biomass aggregates

[0039] According to the present invention, step (1) is a step of forming a product including P4HB biomass aggregates by adding a polymer coagulant to a culture solution.

[0040] The above culture medium includes a biomass containing P4HB. The culture medium may not be particularly limited as long as it is obtained by culturing a microorganism having the ability to produce biomass containing P4HB. For example, the microorganisms include Bacillus subtilis, Cupriavidus necator, Bacillus cereus, Bacillus brevis, Caulobacter cresentus, Bacillus sphaericus, Bacillus coagulans, Bacillus megaterium, Bacilllus circulands, Bacillus licheniformis, Escherichia coli, Microlanatus phosphovorous, Rhizobium meliloti, Rhizobium viciae, Bredyrhizobium japonicum, Burkholderia cepacia, Burkholderia sacchari, Cupriavidus necactor, Neptunamonas Antarctica, Azobacter vinelandii, Pseudomonas putida, Pseudomonas aeruginosa, Aeromonas caviae, Aeromonas hydrophila, Aeromonas punctate, Alcaligenes latus,It may include at least one species selected from the group consisting of Halomonas boliviensis, Lactobacillus rhamnosus, and Firmicutes bacterium, but is not limited thereto. Meanwhile, the culturing is not particularly limited, but may be performed by adjusting the pH of the culture solution containing the microorganism to 2 to 5 and allowing it to stand at a temperature of 30 to 50°C to cause autolysis.

[0041] The culture solution obtained through the above cultivation may undergo a dilution process before the polymer aggregate is added. Specifically, the culture solution may be diluted by adding a solvent such as purified water to the culture solution and stirring it. The dilution ratio of the culture solution is not particularly limited, but may be 2 to 10 times, 2 to 8 times, 2 to 6 times, or 2 to 4 times. When the culture solution is diluted in this way, the culture solution has a concentration suitable for mixing with the polymer aggregate, thereby improving the uniformity of mixing with the polymer aggregate.

[0042] The concentration of biomass containing P4HB included in the culture medium is not particularly limited, but considering the yield of the final recovered biomass, it may be 100 to 250 g / L, 120 to 230 g / L, 140 to 220 g / L, 160 to 210 g / L, or 170 to 200 g / L.

[0043] In addition, the content of the P4HB contained in the biomass is not particularly limited, but may be 65 wt% or more, 70 wt% or more, 75 wt% or more, 80 wt% or more, 85 wt% or more, or 90 wt% or more (e.g., 65 to 95 wt%, 68 to 93 wt%, 70 to 90 wt%, or 70 to 85 wt%) based on the total weight of the biomass containing P4HB.

[0044] The polymer coagulant may not be particularly limited as long as it is a polymer material capable of coagulating biomass containing poly-4-hydroxybutyrate (P4HB) contained in the culture medium. Specifically, the polymer coagulant may include a cationic polymer coagulant having a molecular weight of 1,000,000 Da or more (e.g., 1,000,000 to 10,000,000 Da, 1,000,000 to 5,000,000 Da, 1,300,000 to 4,500,000 Da, 1,500,000 to 4,000,000 Da, 2,000,000 to 3,500,000 Da, 2,300,000 to 3,000,000 Da, or 2,500,000 to 3,000,000 Da). For example, the polymer coagulant may be a polymer coagulant solution in which the cationic polymer coagulant is dissolved or dispersed in a solvent. Since the polymer coagulant includes the cationic polymer coagulant, the coagulation efficiency of biomass containing anionic P4HB can be significantly increased.

[0045] The content of the cationic polymer coagulant may be 0.01 to 10 wt% based on the total weight of the polymer coagulant (e.g., polymer coagulant). Specifically, the content of the cationic polymer coagulant may be 0.03 to 9 wt%, 0.05 to 8 wt%, 0.07 to 7 wt%, 0.08 to 6 wt%, 0.09 to 5 wt%, 0.1 to 3 wt%, 0.1 to 2 wt%, 0.15 to 1.55 wt%, 0.15 to 1.5 wt%, 0.2 to 0.45 wt%, 0.2 to 0.4 wt%, 0.25 to 0.35 wt%, 0.2 to 0.3 wt%, or 0.3 to 0.4 wt% based on the total weight of the polymer coagulant, but is not limited thereto. As the content of the cationic polymer coagulant is within the above range, the coagulation efficiency of the biomass containing P4HB included in the culture solution can be increased.

[0046] The cationic polymer coagulant is not particularly limited as long as it is a polymer material having cationic properties, but may specifically include at least one selected from the group consisting of acrylamide-based polymers, acryloyl-based polymers, amidine-based polymers, polyvinylamine-based polymers, diallyldimethylammonium chloride (DADMAC)-based polymers, and polyamine-based polymers. For example, the cationic polymer coagulant may be a coagulant having a cationicity of 40 mol% and a molecular weight of 3,000,000 Da or more, such as SNF FO4800, Basf Zetag 8185, and Kolon Life Science K912C and K6691.

[0047] When the polymer flocculant is added to the culture medium, the biomass containing P4HB contained in the culture medium and the polymer flocculant are combined to form a product containing P4HB biomass aggregates. At this time, the amount of the polymer flocculant added to the culture medium is not particularly limited, but considering the production efficiency of the product containing the P4HB biomass aggregates, 5 to 80 g (e.g., 5 to 60 g, 10 to 50 g, 10 to 45 g, 15 to 40 g, 20 to 35 g, or 20 to 30 g) of the polymer flocculant may be added per 100 g of the culture medium.

[0048] The average particle size of the P4HB biomass aggregates included in the above product may be 2 mm or more. Specifically, the average particle size of the P4HB biomass aggregates may be, but is not limited to, 3 mm or more, 5 mm or more, 10 mm or more, 20 mm or more, 50 mm or more, 80 mm or more, 100 mm or more, 150 mm or more, 200 mm or more, 250 mm or more, 300 mm or more, 350 mm or more, 400 mm or more, 450 mm or more, or 500 mm or more (e.g., 2 to 500 mm, 5 to 300 mm, 10 to 200 mm, 15 to 100 mm, or 20 to 50 mm). As the average particle size of the above P4HB biomass aggregate is within the above range, the compressibility is improved while minimizing the loss of the P4HB biomass aggregate, and the dehydration by compression is also secured during the drying process described below, so that the biomass containing P4HB can be recovered at a high yield.

[0049]

[0050] Step (2): Separation of P4HB biomass aggregates

[0051] According to the present invention, step (2) is a step of separating the P4HB biomass aggregates from the product formed in step (1). This step (2) can be performed using a specific device so that the P4HB biomass aggregates can be separated at a high content while lowering the moisture content of the product to a desired level.

[0052] The separation in the above step (2) can be performed by at least one selected from the group consisting of a press and an electroosmotic dehydrator. Specifically, the separation in the above step (2) can be performed using a press, an electroosmotic dehydrator, or both. In particular, since the average particle size of the P4HB biomass aggregates is in the order of mm as described above, and the particle size is relatively large (for example, compared to P4HB biomass aggregates having a size of 2 to 15 μm obtained by crushing conventional P4HB-containing biomass cells and then mechanically separating and coagulating them), dehydration using the press can be easily performed.

[0053] More specifically, the step (2) may include a step of (2-1) feeding the product into a press and dehydrating it for the first time to obtain a P4HB biomass aggregate cake; and a step of (2-2) feeding the P4HB biomass aggregate cake into an electroosmotic dehydrator and dehydrating it for the second time to obtain the P4HB biomass aggregate.

[0054] Alternatively, the step (2) may include (2-1) 'a step of putting the product into an electroosmotic dehydrator and performing a first dehydration to obtain a P4HB biomass aggregate; and (2-2)' a step of putting the P4HB biomass aggregate into a press and performing a second dehydration to obtain the P4HB biomass aggregate cake.

[0055] The above step (2-1) is a step of introducing a product including the P4HB biomass aggregate formed in the above step (1) into a press and first dehydrating it to initially lower the moisture content of the product. The press is not particularly limited as long as it is a commonly known press, and specifically, it may be a screw press, a wedge press, a hydraulic press, etc.

[0056] The operating pressure of the press (e.g., the operating pressure of the pressing plate provided in the press) is not particularly limited, but may be 0.01 to 1 MPa. Specifically, the operating pressure of the press may be 0.03 to 0.9 MPa, 0.05 to 0.7 MPa, 0.1 to 0.6 MPa, 0.2 to 0.5 MPa, or 0.3 to 0.4 MPa, but is not limited thereto. When the operating pressure of the press is within the above range, the primary dehydration of the product can be maximized while preventing damage to the P4HB biomass aggregates included in the product.

[0057] By performing primary dehydration through the above press, a P4HB biomass aggregate cake having a moisture content (A) controlled to 60% or less can be obtained. Specifically, the moisture content (A) of the P4HB biomass aggregate cake may be 58% or less, 55% or less, 53% or less, 52% or less, or 51% or less (e.g., 50 to 60%, 50 to 54%, or 51 to 52%). The moisture content (A) may refer to the weight ratio of moisture in the total weight of the P4HB biomass aggregate cake.

[0058] The above step (2-2) is a step of putting the P4HB biomass aggregate cake obtained in the above step (2-1) into an electroosmotic dehydrator and dehydrating it for a second time to secondarily lower the moisture content of the P4HB biomass aggregate cake while removing impurities (e.g., water-soluble impurities). The electroosmotic dehydrator may not be particularly limited as long as it is a dehydrator that uses the electrophoresis principle. By using such an electroosmotic dehydrator, the cell membrane of the P4HB biomass cells is destroyed, so that moisture and impurities within the cells can be efficiently discharged and removed. In addition, dehydration of pore water and surface water present in the P4HB biomass aggregate cake obtained through the press may also be possible.

[0059] The operating conditions of the electroosmotic dehydrator are not particularly limited, but the operating speed may be 0.1 to 4 m / min, and the applied voltage may be 10 to 150 V. Specifically, the operating speed of the electroosmotic dehydrator may be 0.5 to 3.5 m / min, 0.7 to 3 m / min, 0.9 to 2.5 m / min, 1 to 2 m / min, or 1.1 to 1.5 m / min, and the applied voltage of the electroosmotic dehydrator may be, but is not limited to, 12 to 130 V, 13 to 100 V, 15 to 50 V, 17 to 30 V, or 19 to 25 V. When the operating conditions of the electroosmotic dehydrator are within the above range, the secondary dehydration and impurity removal of the P4HB biomass aggregate cake can be maximized.

[0060] By performing secondary dehydration through the above-described electroosmotic dehydrator, a P4HB biomass aggregate with a moisture content (B) controlled to 30% or less can be obtained. Specifically, the moisture content (B) of the P4HB biomass aggregate may be 28% or less, 26% or less, 25% or less, 24% or less, or 23% or less (e.g., 20 to 30%, 21 to 27%, or 22 to 25%). The moisture content (B) may refer to the ratio of the weight of moisture in the total weight of the P4HB biomass aggregate.

[0061]

[0062] Step (3): Fluid accelerator coating

[0063] According to the present invention, step (3) is a step of coating the P4HB biomass aggregate separated in step (2) with a fluidity promoter. By coating the P4HB biomass aggregate with the fluidity promoter, fluidity is secured when producing various compounds using P4HB biomass as a starting material (e.g., fluidity of P4HB biomass is secured in a GBL conversion process), thereby increasing the productivity of the various compounds.

[0064] The above fluidity accelerator is not particularly limited, but may include a metal salt when considering the coating property for the P4HB biomass aggregate, the fluidity of the P4HB biomass, etc. The metal salt is not particularly limited, but may include a divalent metal that forms a divalent metal cation and a divalent anion in an aqueous solution. Specifically, the metal salt may include at least one selected from the group consisting of ferric sulfate, iron sulfate, iron chloride, ferric chloride, calcium chloride, calcium carbonate, calcium hydroxide, calcium sulfate, magnesium sulfate, magnesium chloride, and magnesium carbonate, but is not limited thereto.

[0065] The coating content of the fluidity promoter may be 0.1 to 20 wt% based on the total weight of the P4HB biomass aggregate separated in the step (2). Specifically, the coating content of the fluidity promoter may be 0.5 to 18 wt%, 1 to 15 wt%, 2 to 13 wt%, 3 to 12 wt%, 5 to 10 wt%, or 6 to 9 wt% based on the total weight of the P4HB biomass aggregate. When the coating content of the fluidity promoter is within the above range, the coating property for the P4HB biomass aggregate and the fluidity of the P4HB biomass can be optimized.

[0066]

[0067] Step (4): Drying of P4HB biomass aggregates

[0068] According to the present invention, step (4) is a step of drying the P4HB biomass aggregate coated with the fluidity accelerator in step (3) to obtain P4HB biomass. The drying of the P4HB biomass aggregate is not particularly limited, but may be performed using a natural wind dryer. As the drying is performed using the natural wind dryer, the conventional problem of solidifying or sticking of P4HB having a melting temperature of about 75°C due to drying at a high temperature to equipment can be improved, and P4HB biomass with a controlled moisture content at a desired level can be obtained.

[0069] The operating conditions of the above natural wind dryer are not particularly limited, but the air temperature is 30 to 90 ℃ and the air pressure is 0.1 to 10 kgf / cm 2 , and the air flow rate may be 0.1 to 30 L / min, and the belt speed may be 0.05 to 3 m / min. Specifically, the air temperature of the natural wind dryer may be 40 to 85 ℃, 45 to 80 ℃, 50 to 75 ℃, or 55 to 70 ℃, and the air pressure of the natural wind dryer may be 1 to 9 kgf / cm2 , 2 to 8 kgf / cm 2 , 3 to 7 kgf / cm 2 , or 4 to 6 kgf / cm 2 The air flow rate of the natural wind dryer may be, but is not limited to, 0.5 to 20 L / min, 0.8 to 10 L / min, 1 to 5 L / min, or 1.5 to 3 L / min. In addition, the belt speed of the natural wind dryer may be, but is not limited to, 0.08 to 2.5 m / min, 0.1 to 2 m / min, 0.15 to 1 m / min, or 0.2 to 0.5 m / min.

[0070] By performing drying through the above natural wind dryer, P4HB biomass can be obtained with a moisture content (C) controlled to 10% or less. Specifically, the moisture content (C) of the P4HB biomass may be 8% or less, 7% or less, 6% or less, 5% or less, 4% or less, or 3% or less (e.g., 3 to 10%, 4 to 9%, or 5 to 8%). The moisture content (C) may refer to the ratio of the weight of moisture in the total weight of the P4HB biomass.

[0071]

[0072] Thereafter, the P4HB biomass obtained through drying in the above step (4) can be used as a starting material for producing various compounds after undergoing a commonly known purification process, etc.

[0073]

[0074] In this way, the method for recovering biomass containing P4HB according to the present invention can recover P4HB biomass at a high yield even through a simplified process compared to the conventional one. Specifically, the method for recovering biomass according to the present invention can have a yield (recovery rate) of P4HB biomass of 80% or more, 85% or more, 90% or more, 92% or more, 94% or more, 95% or more, 96% or more, 97% or more, or 99% or more (e.g., 85 to 99%, 90 to 98%, or 95 to 97%).

[0075]

[0076] Biomass containing poly-4-hydroxybutyrate

[0077] The biomass containing poly-4-hydroxybutyrate according to the present invention is obtained by the above-described method for recovering biomass containing poly-4-hydroxybutyrate. Since the biomass containing poly-4-hydroxybutyrate according to the present invention is obtained through the above-described recovery method, it can have high purity and contain a high content of poly-4-hydroxybutyrate. Specifically, the content of poly-4-hydroxybutyrate contained in the biomass obtained through the above-described recovery method may be 65 wt% or more, 70 wt% or more, 75 wt% or more, 80 wt% or more, 85 wt% or more, or 90 wt% or more (e.g., 65 to 95 wt%, 70 to 90 wt%, or 70 to 85 wt%), based on the total weight of the biomass containing poly-4-hydroxybutyrate (P4HB biomass). The biomass comprising the above poly-4-hydroxybutyrate may comprise poly-4-hydroxybutyrate alone, or may comprise another polymer together with poly-4-hydroxybutyrate, or may comprise a copolymer in which one or more monomers different from 4-hydroxybutyrate (e.g., 3-hydroxybutyrate, 3-hydroxypropionate, 3-hydroxyhexanoate, 3-hydroxyvalerate, 4-hydroxyvalerate, 5-hydroxyvalerate, 6-hydroxyhexanoate, etc.) are polymerized with 4-hydroxybutyrate. The biomass comprising poly-4-hydroxybutyrate according to the present invention can be usefully used as a starting material (initial raw material) for the production (manufacture) of various compounds.

[0078]

[0079] Method for preparing a compound

[0080] The method for producing a compound according to the present invention relates to a method for producing a compound using biomass containing the above-described poly-4-hydroxybutyrate. Specifically, the method for producing the compound comprises a step of processing the biomass containing the above-described poly-4-hydroxybutyrate. The processing may include, but is not limited to, a pyrolysis reaction, a hydrogenation reaction, a microbial reaction, an enzymatic reaction, or a polymerization reaction.

[0081] For example, the method for producing the compound comprises the steps of (a) recovering biomass from a method for recovering biomass containing poly-4-hydroxybutyrate; and (b) processing the recovered biomass.

[0082] According to the present invention, step (a) is a step of recovering biomass using the above-described method for recovering biomass containing poly-4-hydroxybutyrate. By recovering biomass using the above-described recovery method, biomass containing a high content of poly-4-hydroxybutyrate with high purity can be recovered.

[0083] According to the present invention, step (b) is a step of processing the recovered biomass. The processing may include, but is not limited to, a pyrolysis reaction, a hydrogenation reaction, a microbial reaction, an enzymatic reaction, or a polymerization reaction.

[0084] The compound obtained through such processing may be, but is not limited to, a raw material compound including at least one of gamma-butyrolactone (GBL), 1,4-butanediol (BDO), tetrahydrofuran (THF), and 2-pyrrolidinone; a derivative of the raw material compound (e.g., methylpyrrolidone (NMP), ethylpyrrolidone (NEP), etc.); or a polymer using the raw material compound (e.g., polybutylene terephthalate (PBT), polypyrrolidone, etc.).

[0085] The compound according to the present invention can be effectively applied as a solvent in the electronic / electrical field, the chemical field, etc., or as an intermediate compound for the synthesis of other compounds.

[0086] The present invention is described in more detail through the following examples. However, the following examples are intended only to illustrate the present invention and are not intended to limit the scope of the present invention.

[0087]

[0088] [Example]

[0089] Step (1): Formation of a product containing P4HB biomass aggregates

[0090] A culture medium (fermentation medium) with a P4HB biomass concentration of 180 g / L was prepared. At this time, the content of P4HB contained within the P4HB biomass was approximately 70 to 85 wt%. Next, purified water was added to the prepared culture medium to dilute the culture medium by 2 times so that the culture medium could be uniformly mixed with the polymer coagulant below.

[0091] Next, a cationic polymer coagulant (SNF, FO4800) having a molecular weight of 3,000,000 Da or more was added to water and stirred for 1 hour to prepare a polymer coagulant in which the cationic polymer coagulant was dissolved (specifically, a polymer coagulant solution (diluted solution) in which the cationic polymer coagulant content (concentration) was 0.3 wt%).

[0092] Next, the polymer flocculant was added to the diluted culture solution at an amount of 20 g per 100 g of the diluted culture solution and mixed to form a clear product containing P4HB biomass flocs having a particle size of 2 mm or more.

[0093] Step (2): Separation of P4HB biomass flocs from the product

[0094] - Step (2-1): Primary dehydration of the product through a press

[0095] The product formed in the above step (1) was placed in a press (Screw press dehydrator SP-30, Hwain Co., Ltd.) with the differential rpm of the outer cylinder and screw set to 0.46 and the pressure of the pressure plate set to 0.3 MPa at 500 m 2 / hr and was dehydrated (pressed) for the first time to obtain a P4HB biomass aggregate cake with a moisture content of 51.42%.

[0096] - Step (2-2): Secondary dehydration of P4HB biomass aggregate cake using an electroosmotic dehydrator.

[0097] The P4HB biomass aggregate cake obtained in the above step (2-1) was put into an electroosmotic dehydrator (EOD-500S, Hwain Co., Ltd.) set at an operating speed of 1.2 m / min and an applied voltage of 20 V, and dehydrated a second time to obtain a P4HB biomass aggregate with a moisture content of 23.13%.

[0098] Step (3): Coating of P4HB biomass aggregates

[0099] The P4HB biomass aggregates obtained in the above step (2-2) were sprayed with 40% concentration of ferric sulfate (Nextech Co., Ltd.) using a sprayer to coat the P4HB biomass aggregates with ferric sulfate. At this time, the coating ratio was adjusted so that 8 wt% of the total weight of the P4HB biomass aggregates was coated with the ferric sulfate.

[0100] Step (4): Drying of P4HB biomass aggregates

[0101] In the above step (3), the P4HB biomass aggregate coated with ferric sulfate was heated at an air temperature of 60°C and an air pressure of 5 kgf / cm. 2 P4HB biomass was obtained by placing it in a natural wind dryer (Hwain Co., Ltd., model-1000D) set to an air flow rate of 2 L / min and a belt speed of 0.3 m / min and drying it.

[0102]

[0103] [Comparative example]

[0104] Step 1: Disruption of P4HB biomass cells

[0105] A culture solution was prepared with a P4HB biomass concentration of 180 g / L. At this time, the content of P4HB contained within the P4HB biomass was approximately 70-85 wt%. Subsequently, purified water was added to the culture solution to dilute the culture solution so that the P4HB biomass concentration became 110 g / L. Next, the culture solution was added to a high pressure homogenizer (HPH) (Gear) set to 500 bar to perform P4HB biomass cell disruption.

[0106] Step 2: Removal of impurities and cells through mechanical separator (M / S) treatment

[0107] In the above step 1, the culture solution in which cells were disrupted was treated with a mechanical separator (Alfa Laval, Clara) to remove water-soluble impurities (amino acids, organic acids, ions, etc.) and cells contained in the culture solution. At this time, before the M / S treatment, purified water was added to the culture solution in which cells were disrupted to dilute the culture solution so that the concentration of P4HB biomass became 40 g / L. In addition, the M / S treatment was performed at 7400 rpm, an interval time of 75 seconds, and a feeding flow rate of 900 L / hr. Thereafter, a P4HB biomass concentrate having a moisture content of 82.1% was obtained through the M / S treatment.

[0108] Step 3: Coagulation of P4HB biomass concentrate

[0109] The P4HB biomass concentrate obtained in the above step 2 was diluted twice by adding purified water. Next, CaCl2·2H2O (Daejung Chemical Co., Ltd.) corresponding to 2.3 wt% of the total weight of the diluted P4HB biomass concentrate was added to the P4HB biomass concentrate, and the temperature was raised to 60°C while stirring and maintained for 1 hour.

[0110] Next, the P4HB biomass concentrate containing CaCl2·2H2O was cooled to 40°C, and then 40% concentration of ferric sulfate (Nextech Co., Ltd.) was added and stirred at high speed to coagulate the P4HB biomass concentrate. At this time, the ferric sulfate was added at 10 wt% of the total weight of the P4HB biomass concentrate.

[0111] Step 4: Filter press (F / P) of P4HB biomass coagulant

[0112] The P4HB biomass aggregate obtained in the above step 3 was filtered at a permeability of 20 cc / cm 2 A P4HB biomass cake with a moisture content of 44.0% was obtained by filter pressing using a filter cloth (Jeongdo Enterprise Co., Ltd.) with a flow rate of 100 / min. At this time, the filter press was performed by blowing high-pressure air of 3 to 6 bar for 1 hour after feeding was completed.

[0113] Step 5: Drying of P4HB biomass cake

[0114] The P4HB biomass cake obtained in the above step 4 was first dried with a fan at room temperature to reduce the moisture content to 25%. Next, the P4HB biomass cake with a moisture content of 25% was fed into a pin mill and ground to obtain fine P4HB biomass powder. Then, the supply air volume was 65°C and 1050 m 3P4HB biomass powder was fed into a fluidized bed dryer (Daesung Machinery Industry Co., Ltd.) set to / h, internal temperature 45 ℃, and coil temperature 48 ℃, and dried for a second time to obtain P4HB biomass.

[0115]

[0116] [Example 1]

[0117] In each of the examples and comparative examples, the moisture content of the obtained product at each step was calculated using Equation 1 below, and the results are shown in Table 1 below.

[0118] [Formula 1]

[0119] Moisture content (%) = 100 (%) - Sample solids content (%)

[0120] Sample solids content (%) =

[0121]

[0122] [Example 2]

[0123] The yield of the P4HB biomass finally obtained in each of the examples and comparative examples was calculated using Equation 2 below, and the results are shown in Table 1 below.

[0124] [Formula 2]

[0125] Yield (%) =

[0126] In the above equation 2,

[0127] P1 is the amount of P4HB contained in the initially supplied process liquid before the recovery process,

[0128] P2 is the amount of P4HB contained in the process liquid obtained after the recovery process.

[0129]

[0130] [Example 3]

[0131] In each of the examples and comparative examples, the loss rate (loss, %) of P4HB biomass occurring at each step was calculated using Equation 3 below, and the results are shown in Table 1 below.

[0132] [Formula 3]

[0133] Loss rate (loss, %) = 100(%) - yield (%)

[0134]

[0135] Example Recovery process Fermentation liquid aggregate production Pressing Electro-osmosis Dehydration Coating and natural wind drying P4HB Biomass moisture content 80 % 90 % 51.42 % 23.13 % 6.56 % - Loss rate - 1~2 % 1~2 % 0.5~1 % - Yield----- 97 % Comparative example Recovery process Fermentation liquid Cell crushing M / S treatment Aggregation F / P Primary drying Secondary drying P4HB Biomass moisture content 80 % 87 % 82.1 % 90 % 44.0 % 25 % 2.8 % - Loss rate - 13 % - 4 % - 5 % - Yield------- 79 %

[0136] Referring to Table 1 above, it can be confirmed that the example of recovering P4HB biomass using the recovery method according to the present invention has a significantly higher yield of P4HB biomass compared to the comparative example, which is a conventional recovery method. In particular, the present invention can recover P4HB biomass at a high yield even if steps such as cell crushing and M / S treatment included in the conventional recovery method are omitted, thereby achieving process simplification, improved productivity, and reduced investment costs.

[0137] In addition, in the embodiment of recovering P4HB biomass using the recovery method according to the present invention, unlike the comparative example in which the dilution process is performed in multiple stages such as cell crushing, M / S treatment, and coagulation, the dilution process is performed only in the stage of forming a product including P4HB biomass aggregates, so that the amount of wastewater generated during the dilution process can also be reduced.

Claims

1. (1) A step of forming a product including poly-4-hydroxybutyrate (P4HB) biomass aggregates by adding a polymer coagulant to a culture solution; (2) A step of separating the P4HB biomass aggregate from the product; (3) a step of coating the separated P4HB biomass aggregate with a flow promoter; and (4) A method for recovering biomass containing poly-4-hydroxybutyrate, comprising a step of drying the coated P4HB biomass aggregate.

2. In paragraph 1, A method for recovering biomass, wherein the polymer coagulant comprises a cationic polymer coagulant having a molecular weight of 1,000,000 Da or more.

3. In paragraph 2, A method for recovering biomass, wherein the content of the cationic polymer coagulant is 0.01 to 10 wt% based on the total weight of the polymer coagulant.

4. In paragraph 2, A method for recovering biomass, wherein the cationic polymer coagulant comprises at least one selected from the group consisting of acrylamide-based polymers, acryloyl-based polymers, amidine-based polymers, polyvinylamine-based polymers, diallyldimethylammonium chloride (DADMAC)-based polymers, and polyamine-based polymers.

5. In paragraph 1, A method for recovering biomass, wherein the average particle size of P4HB biomass aggregates included in the above product is 2 mm or more.

6. In paragraph 1, A method for recovering biomass, wherein the separation in the above step (2) is performed by at least one selected from the group consisting of a press and an electroosmotic dehydrator.

7. In paragraph 1, The above step (2) (2-1) A step of putting the above product into a press and performing a first dehydration to obtain a P4HB biomass aggregate cake; and (2-2) A method for recovering biomass, comprising the step of introducing the above P4HB biomass aggregate cake into an electroosmotic dehydrator and performing secondary dehydration to obtain the above P4HB biomass aggregate.

8. In paragraph 7, A method for recovering biomass, wherein the operating pressure of the press is 0.01 to 1 MPa.

9. In paragraph 7, A method for recovering biomass, wherein the above-mentioned electroosmotic dehydrator has an operating speed of 0.1 to 4 m / min and an applied voltage of 10 to 150 V.

10. In paragraph 1, A method for recovering biomass, wherein the above-mentioned fluidizing promoter comprises a metal salt.

11. In paragraph 10, A method for recovering biomass, wherein the metal salt comprises at least one selected from the group consisting of ferric sulfate, iron sulfate, iron chloride, ferric chloride, calcium chloride, calcium carbonate, calcium hydroxide, calcium sulfate, magnesium sulfate, magnesium chloride, and magnesium carbonate.

12. In paragraph 1, A method for recovering biomass, wherein the coating content of the above-mentioned fluidizing promoter is 0.1 to 20 wt% based on the total weight of the P4HB biomass aggregate separated in the above-mentioned step (2).

13. In paragraph 1, A method for recovering biomass, wherein the drying in the above step (4) is performed using a natural wind dryer.

14. In paragraph 13, The above natural wind dryer has an air temperature of 30 to 90 ℃ and an air pressure of 0.1 to 10 kgf / cm 2 A method for recovering biomass, wherein the air flow rate is 0.1 to 30 L / min and the belt speed is 0.05 to 3 m / min.

15. In paragraph 1, A method for recovering biomass, wherein the yield of P4HB biomass is 80% or more.

16. Biomass containing poly-4-hydroxybutyrate obtained from a method for recovering biomass containing poly-4-hydroxybutyrate according to paragraph 1.

17. A method for producing a compound, comprising the step of processing biomass containing poly-4-hydroxybutyrate according to claim 16.

18. In paragraph 17, A method for producing a compound, wherein the compound is a raw material compound comprising at least one of gamma-butyrolactone (GBL), 1,4-butanediol (BDO), tetrahydrofuran (THF), and 2-pyrrolidinone, a derivative of the raw material compound, or a polymer using the raw material compound.

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