# US 11,440,823 B2 · Method for producing polyhydroxyalkanoic acid > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,440,823 B2 - Document ID: US11440823B2 - Status: Granted - Kind: B2 - Application number: 16/311,536 - Filed: 2017-06-12 - Published: 2019-10-31 - Granted: 2022-09-13 - Earliest claimed: 2016-06-23 - Assignees: Kaneka Corporation - Applicants: Kaneka Corporation - Inventors: Masaki Takita - Web page: https://patentgrep.com/patent/US11440823B2 ## CPC - C02F 3/302: {Nitrification and denitrification treatment (C02F3/308 takes precedence)} - C02F 3/34: characterised by the microorganisms used - C02F 3/305: {characterised by the denitrification} - C02F 3/341: {Consortia of bacteria} - C08G 63/90: Purification; Drying - C12P 7/625: Polyesters of hydroxy carboxylic acids - C02F 3/26: using pure oxygen or oxygen-rich gas - C02F 3/301: {Aerobic and anaerobic treatment in the same reactor} - C02F 2101/16: Nitrogen compounds, e.g. ammonia - C02F 2101/163: {Nitrates} - C02F 2101/34: containing oxygen - C02F 2209/02: Temperature - C02F 2209/06: pH - C02F 2209/22: O2 - C02F: TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE (separation in general B01D; special arrangements on waterborne vessels of installations for treating water, waste water or sewage, e.g. for producing fresh water, B63J; adding materials to water to prevent corrosion C23F; treating radioactively-contaminated liquids G21F9/04; regeneration of reactants for recirculation into processes, see the relevant places for the processes) - C08G: MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS - C12P: FERMENTATION OR ENZYME-USING PROCESSES TO SYNTHESISE A DESIRED CHEMICAL COMPOUND OR COMPOSITION OR TO SEPARATE OPTICAL ISOMERS FROM A RACEMIC MIXTURE {(brewing of beer C12C; producing vinegar C12J; producing specific peptides or proteins C07K; producing enzymes C12N9/00; DNA or RNA concerning genetic engineering, vectors, e.g. plasmids, or their isolation, preparation or purification C12N15/00; measuring or testing processes involving enzymes or microorganisms C12Q; measuring or testing processes involving nucleic acid amplification reactions C12Q1/6844; fermentation processes to form a food composition, A21 or A23; compounds in general, see the relevant compound class, e.g. C01, C07)} ## Abstract An object of the present invention is to provide a method for producing PHA, which is capable of suppressing the cost of overall production equipment including a waste water treatment process in production of PHA using microorganisms. Provided is a method including: a production step of purifying or molding polyhydroxyalkanoic acid biosynthesized in bacterial cells of a microorganism; a discharge step of discharging waste water containing nitrogen-containing impurities from the production step; and a nitrogen removal step of biologically treating the waste water to remove the nitrogen-containing impurities from the waste water. In the method, the residual ratio of the polyhydroxyalkanoic acid in the production step is 99% by weight or less, and the waste water that is biologically treated in the nitrogen removal step contains the polyhydroxyalkanoic acid in addition to the nitrogen-containing impurities. ## Claims ### Claim 1 A method for producing polyhydroxyalkanoic acid, the method comprising: purifying or molding polyhydroxyalkanoic acid biosynthesized in bacterial cells of a microorganism; discharging waste water produced during the purifying or molding, the waste water comprising nitrogen-containing impurities; and biologically treating the waste water to remove the nitrogen-containing impurities from the waste water, wherein a ratio of a weight of the polyhydroxyalkanoic acid obtained by the purifying or the molding to a weight of the polyhydroxyalkanoic acid biosynthesized in the bacterial cells is 99% by weight or less, and the waste water that is biologically treated comprises the polyhydroxyalkanoic acid in addition to the nitrogen-containing impurities. ### Claim 2 (depends on 1) The method according to claim 1, wherein the purifying or molding comprises disrupting the microorganism containing biosynthesized polyhydroxyalkanoic acid by a physical, chemical or biological method and decomposing and/or removing impurities other than the polyhydroxyalkanoic acid to purify the polyhydroxyalkanoic acid. ### Claim 3 (depends on 1) The method according to claim 1, wherein the nitrogen-containing impurities comprise a water-soluble or water-dispersible component formed by decomposing a protein, a lipid or a nucleic acid derived from the microorganism during the purifying. ### Claim 4 (depends on 1) The method according to claim 1, wherein in the discharging, the polyhydroxyalkanoic acid contained in the waste water has a volume average particle size of 5000 μm or less. ### Claim 5 (depends on 1) The method according to claim 1, wherein the waste water that is biologically treated comprises dissolved oxygen in an amount of 1.5 ppm or more. ### Claim 6 (depends on 1) The method according to claim 1, wherein the waste water that is biologically treated has a temperature of 10 degrees Celsius or higher and 60 degrees Celsius or lower. ### Claim 7 (depends on 1) The method according to claim 1, wherein the waste water that is biologically treated has a pH of 3 or more and 10 or less. ### Claim 8 (depends on 1) The method according to claim 1, wherein the ratio of the weight of the polyhydroxyalkanoic acid obtained by the purifying or the molding to the weight of the polyhydroxyalkanoic acid biosynthesized in the bacterial cells is 50 to 98% by weight. ### Claim 9 (depends on 1) The method according to claim 1, wherein the ratio of the weight of the polyhydroxyalkanoic acid obtained by the purifying or the molding to the weight of the polyhydroxyalkanoic acid biosynthesized in the bacterial cells is 60 to 97% by weight. ### Claim 10 (depends on 1) The method according to claim 1, wherein in the discharging, the polyhydroxyalkanoic acid contained in the waste water has a volume average particle size of 100 μm or less. ### Claim 11 (depends on 1) The method according to claim 1, wherein the waste water that is biologically treated comprises dissolved oxygen in an amount of 2 to 4 ppm. ### Claim 12 (depends on 1) The method according to claim 1, wherein the waste water that is biologically treated has a temperature of 15 degrees Celsius or higher and 55 degrees Celsius or lower. ### Claim 13 (depends on 1) The method according to claim 1, wherein the waste water that is biologically treated has a pH of 4 or more and 9 or less. ### Claim 14 (depends on 1) The method according to claim 1, wherein the polyhydroxyalkanoic acid is at least one selected from the group consisting of 3-hydroxybutyrate, 4-hydroxybutyrate, 3-hydroxyhexanonate, 3-hydroxypropionate, 3-hydroxyvalerate, 3-hydroxyhexanoate, 3-hydroxyheptanoate, and 3-hydroxyoctanoate. ### Claim 15 (depends on 1) The method according to claim 1, wherein the biological treating of the waste water comprises contacting the waste water with bacterial cells capable of decomposing biodegradable resin, bacterial cells having a nitrification ability, or bacterial cells having a denitrification ability.