DIPLOID STRAIN OF ASPERGILLUS NIGER AS PRODUCER OF CITRIC ACID Russian patent published in 2003 - IPC

FIELD: microbiology, biotechnology. SUBSTANCE: strain can be used as producer of citric acid in fermentation of carbohydrate-containing media by submerged method. Diploid strain Aspergillus niger VKPM F-817 is obtained by selection using polyploidy method. In fermentation with the novel strain the yield of citric acid of sugar added is: in diluted molasses medium with sugar concentration 30 g/g/dm³, 87.0%; in concentrated molasses medium with sugar concentration 130 g/g/dm³, 66% and in sucrose-mineral medium with sugar concentration 150 g/g/dm³, 95.6%. Invention provides preparing the novel diploid strain of Aspergillus niger showing resistance against morphological variability in storage and stably high productivity. EFFECT: valuable properties of strain, increased yield of citric acid. 2 tbl, 3 ex