# US 4,391,908 A · Method for producing citric acids > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 4,391,908 A - Document ID: US4391908A - Status: Granted - Kind: A - Application number: 05/916,262 - Filed: 1978-06-16 - Granted: 1983-07-05 - Earliest claimed: 1967-06-07 - Assignees: Takeda Chemical Industries, Ltd. - Inventors: Takeshi Tabuchi; Matazo Abe - Web page: https://patentgrep.com/patent/US4391908A ## CPC - C12P 7/48: Tricarboxylic acids, e.g. citric acid - Y10S 435/921: Candida - Y10S 435/923: Candida lipolytica - Y10S 435/924: Candida tropicalis - 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)} - Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS ## Abstract Citric acids are produced by culturing a citric acids-accumulating and hydrocarbon-assimilating strain of a yeast of the genus Candida in an aqueous medium containing, as main carbon source, at least one normal paraffin with from 9 to 20 carbon atoms, inclusive, in the molecule, at a specific pH, and recovering accumulated citric acids from the culture broth. ## Claims ### Claim 1 A method for producing (+)-isocitric acid which comprises inoculating a (+)-isocitric acid-accumulating and hydrocarbon-assimilating strain of a yeast belonging to the genus Candida in an aqueous culture medium containing at least one normal paraffin containing 9 to 20 carbon atoms in the molecule as the main carbon source; incubating the culture at a pH of from about 4 to about 7.5 until (+)-isocitric acid is substantially accumulated in the culture broth; and separating the so-accumulated (+)-isocitric acid therefrom. ### Claim 2 (depends on 1) A method according to claim 1, wherein the incubation temperature is between 15.degree. and 40.degree. C. ### Claim 3 (depends on 1) A method according to claim 1, wherein the pH of the culture medium is maintained between 5 and 6.5. ### Claim 4 (depends on 1) A method according to claim 1, wherein the yeast is Candida lipolytica. ### Claim 5 (depends on 1) A method according to claim 1, wherein the yeast is Candida tropicalis. ### Claim 6 (depends on 1) A method according to claim 1, wherein the yeast is Candida intermedia. ### Claim 7 (depends on 1) A method according to claim 1, wherein the yeast is Candida parapsilosis. ### Claim 8 (depends on 1) A method according to claim 1, wherein the yeast is Candida quilliermondii. ### Claim 9 (depends on 1) A method according to claim 1, wherein the yeast is Candida brumptii. ### Claim 10 (depends on 1) A method according to claim 1, wherein the yeast is Candida sp. (ATCC 20180). ### Claim 11 (depends on 4) A method according to claim 4, wherein the yeast is Candida lipolytica (ATCC 20114). ### Claim 12 (depends on 4) A method according to claim 4, wherein the yeast is Candida lipolytica (ATCC 20182). ### Claim 13 (depends on 5) A method according to claim 5, wherein the yeast is Candida tropicalis (ATCC 20115). ### Claim 14 (depends on 6) A method according to claim 6, wherein the yeast is Candida intermedia (ATCC 20178). ### Claim 15 (depends on 7) A method according to claim 7, wherein the yeast is Candida parapsilosis (ATCC 20179). ### Claim 16 (depends on 7) A method according to claim 7, wherein the yeast is Candida parapsilosis (ATCC 20181). ### Claim 17 (depends on 8) A method according to claim 8, wherein the yeast is Candida quilliermondii (ATCC 20118). ### Claim 18 (depends on 9) A method according to claim 9, wherein the yeast is Candida brumptii (ATCC 20117). ### Claim 19 (depends on 1) A method according to claim 1, wherein the pH is maintained at from about 4 to about 7.5 during the course of the incubation by the addition of a pH-adjusting agent. ### Claim 20 (depends on 19) A method according to claim 19 wherein said pH-adjusting agent comprises a member of the group of alkalai metal salts, alkaline earth metal salts, ammonium salts, alkali metal hydroxides, alkaline earth metal hydroxides, and ammonium hydroxide. ### Claim 21 (depends on 19) A method according to claim 19, wherein the pH-adjusting agent is calcium carbonate, calcium acetate, sodium hydroxide, calcium hydroxide or aqueous ammonia. ### Claim 22 (depends on 19) A method according to claim 19, wherein the pH is maintained at from about 5 to about 6.5. ### Claim 23 (depends on 1) A method according to claim 1, wherein the culture is incubated in the presence of calcium ions or magnesium ions. ### Claim 24 (depends on 1) A method according to claim 1, wherein said aqueous culture medium also contains a second carbon source. ### Claim 25 (depends on 23) A method according to claim 23, wherein the second carbon source is a carbohydrate. ### Claim 26 A method for producing citric acid and (+)-isocitric acid, which comprises inoculating a citric and (+)-isocitric acids-accumulating and hydrocarbon-assimilating strain of a yeast belonging to the genus Candida, in an aqueous culture medium containing at least one normal paraffin containing 9 to 20 carbon atoms in the molecule as a main carbon source; incubating the culture at a pH of from about 4 to about 7.5 until citric acid and (+)-isocitric acid are substantially accumulated in the culture medium, and separating the so-accumulated citric acid and (+)-isocitric acid therefrom. ### Claim 27 A method for producing (+)-isocitric acid, which comprises inoculating a (+)-isocitric acid-accumulating and hydrocarbon-assimilating strain of a yeast belonging to the genus Candida, in an aqueous culture medium containing at least one normal paraffin containing 9 to 20 carbon atoms in the molecule as a main carbon source; incubating the culture under conditions of pH and temperature such that (+)-isocitric acid is accumulated, for a time until (+)-isocitric acid is substantially accumulated in the culture medium, and separating the so-accumulated (+)-isocitric acid form the culture medium. ### Claim 28 (depends on 27) A method according to claim 27, wherein the pH is maintained at a level at which (+)-isocitric acid is accumulated by the addition of a pH adjusting agent. ### Claim 29 (depends on 27) A method according to claim 27, wherein said pH adjusting agent comprises a member of the group of alkali metal salts, alkaline earth metal salts, ammonium salts, alkali metal hydroxides, alkaline earth metal hydroxides, and ammonium hydroxide. ### Claim 30 (depends on 27) A method according to claim 27, wherein the yeast is Candida lipolytica, Candida tropicalis, Candida intermedia, Candida parapsilosis, or Candida guilliermondii. ### Claim 31 (depends on 27) A method according to claim 27, wherein the yeast is Candida lipolytica. ### Claim 32 (depends on 31) A method according to claim 31, wherein the yeast is Candida lipolytica (ATCC 20114). ### Claim 33 (depends on 31) A method according to claim 31, wherein the yeast is Candida lipolytica (ATCC 20182). ### Claim 34 (depends on 27) A method according to claim 27, wherein the yeast is a citric and (+)-isocitric acids-accumulating and hydrocarbon-assimilating strain of a yeast belonging to the genus Candida, said incubation is conducted until citric acid and (+)-isocitric acids are substantially accumulated in the culture medium, and further comprising separating the so-accumulated citric acid from the culture medium.