YEAST STRAIN YARROWIA LIPOLYTICA - PRODUCER OF CITRIC ACID AND METHOD OF CITRIC ACID PRODUCTION Russian patent published in 1997 - IPC

FIELD: biotechnology. SUBSTANCE: Invention proposes yeast strain Yarrowia lipolytica VKM Y-2785D. Method involves culturing yeast Y. lipolytica on nutrient medium containing ethanol as a single carbon source and zinc and iron ions as trace elements at deficit of nitrogen under aeration conditions. Ethanol is added to nutrient medium continuously and its concentration is maintained at level 0.1-30.0 g/l; at its discrete feeding ethanol concentration is maintained at the following levels: 2.0-2.5 g/l at start of process, 1.0-2.0 g/l at biomass growth and 2.0-5.0 g/l at the stage of citric acid biosynthesis. Concentration of citric acid in cultural medium - up to 130 g/l, its yield is 90-100% (of ethanol). EFFECT: yeast strain indicated above, increased yield of product. 9 cl, 5 tbl