A METHOD FOR THE PRODUCTION OF CARBOXYLIC ACIDS UNDER UNSTERILE CONDITIONS

• US 20200131543A1
• Filed: 06/23/2017
• Published: 04/30/2020
• Est. Priority Date: 06/23/2017
• Status: Active Grant

• Current Assignee: Helmholtz-Zentrum FüR Umweltforschung GmbH - UFZ (Bundesrepublik Deutschland)
• Original Assignee: Helmholtz-Zentrum FüR Umweltforschung GmbH - UFZ (Bundesrepublik Deutschland)
• Inventors: AURICH, Andreas, HUNGER, Steffi, BECKER, Mi-Yong, KOHLHEB, Norbert, MULLER, Roland Arno
• Granted Patent: US 11,597,952 B2
• Time in Patent Office: Days
• CPC Class Codes: C12N 1/16 Yeasts; Culture media therefor
• CPC Class Codes: C12N 2500/60 Buffer, e.g. pH regulation, osmotic pressure
• CPC Class Codes: C12N 2500/70 Undefined extracts conditioned medium C12N2502/00
• CPC Class Codes: C12P 7/40 containing a carboxyl group including Peroxycarboxylic acids
• CPC Class Codes: C12P 7/42 Hydroxy-carboxylic acids
• CPC Class Codes: C12P 7/44 Polycarboxylic acids
• CPC Class Codes: C12P 7/48 Tricarboxylic acids, e.g. citric acid

Abstract

The aim of the invention is to provide a method for biotechnological production of carboxylic acids, in which the acid-forming micro-organisms are cultured in an unsterile manner in a submerged phase containing waste water containing all carbon and nutrient medium components necessary for the production of the carboxylic acid, which method avoids the disadvantages of known methods and enables high product concentrations and productivity while at the same time the resources of water and power are being conserved. This aim is achieved, according to the invention, in that micro-organisms are used that are cultured under unsterile conditions in a culture medium containing waste water with the addition of carbon-rich compounds.

Claims

1-16. -16. (canceled)

17. A method for the biotechnological production of carboxylic acids, in which micro-organisms are used that are cultured under unsterile conditions in a culture medium containing waste water, which contains carbon-rich compounds and/or to which carbon-rich compounds are added, characterized in that as micro-organisms strains of the yeast type Yarrowia lipolytica, yeasts of the genuses Candida oder filamentous fungi are used.

18. The method according to claim 17, characterized in that the strain Yarrowia lipolytica H181 (DSM 7806) is used.

19. The method according to claim 17, characterized in that the carboxylic acids to be produced are aconitic, malic, succinic, citric, fumaric, isocitric, a-ketoglutaric, oxaloacetic and pyruvic and/or itaconic acid, preferably citric acid.

20. The method according to claim 17, characterized in that the waste water used is a water that is contaminated through use and consumption, preferably, the waste water is a grey water, industrial wastewater from the food industry, the chemical, pharmaceutical and biotechnology industry, vegetable oil processing, natural gas and crude oil extraction and processing industry, and/municipal waste water and/or waste water from the cleaning stages of a kitchen and catering operation, discharges from commercial oil/fat separators and/or from the pre-clarification stage of waste water treatment plants for communal waste waters.

21. The method according to claim 17, characterized in that the waste water is fed to a reaction vessel in a volume proportion of 5-100% of the entire culture medium;

preferably with a proportion of 90-100%.

22. The method according to claim 17, characterized in that as carbon-rich compounds (carbon source), substances from mono-, di-, triglycerides, fatty acids, fatty acid methyl or ethyl esters, ethanol, methanol, glycerol, glucose, fructose, galactose, lactose, lactic acid, saccharose, xylose, arabinose and/or n-alkanes (n-paraffin) or waste products from used vegetable and/or animal fats and/or oils, preferably from old deep-frying oil, are used, or that mixtures of the above carbon-rich compounds (carbon source) are used.

23. The method according to claim 17, characterized in that the cultivation is conducted in an unsterile manner and no measures and devices are provided for the production and maintenance of a germ-free and sterile state and for the prevention of the penetration of external germs into the culture medium.

24. The method according to claim 17, characterized in that the cultivation is conducted in a reaction facility, which is present in an open or closed structure or construction, preferably in reaction vessels that are stirrer reactors, airlift reactors, bubble columns or waste water reactors such as aeration tanks or sequencing batch reactors.

25. The method according to claim 17, characterized in that providing and cultivating biomasses, namely all necessary pre-cultivation steps for producing the inoculation biomasses (inoculum) are produced in a sterile and/or unsterile manner.

26. The method according to claim 17, characterized in that the cultivation is conducted with a ph value of 2.0 to 8.0, preferably at ph 3.5 to 5.5.

27. The method according to claim 17, characterized in that the cultivation is conducted at a temperature of 5 to 45°

C., preferably at 26 to 33°

C.

28. The method according to claim 17, characterized in that CaCO3, Ca(OH)2, KOH, NaOH, Na2CO3, NaHCO3, preferably NaOH, is used as a neutralisation agent.

29. The method according to claim 17, characterized in that the dissolved oxygen concentration is set at a range of pO2≤

51% to 100%, preferably pO2≤

20%, during cultivation.

30. The method according to claim 17, characterized in that the cultivation is conducted as a batch, fedbatch, repeated fedbatch (semi-continuous) or continuous process, preferably as a fedbatch or repeated fedbatch method.

31. The method according to claim 17, characterized in that the cultivation takes place without prior immobilisation of the micro-organisms.