Induction and Citric Acid Productivity of Fluoroacetate-sensitive Mutant Strains of Candida lipolytica |
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Authors: | Shun-ichi Akiyama Takashi Suzuki Yasuhiro Sumino Yoshio Nakao Hideo Fukuda |
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Institution: | Microbiological Research Laboratories, Central Research Division, Takeda Chemical Industries, Ltd., Osaka |
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Abstract: | To establish a novel process for the economical production of citric acid from n-paraffins by yeast, attempts were made to obtain some mutant strains capable of producing citric acid in higher yield without (+)-isocitric acid.From among the mutant strains derived from Candida lipolytica ATCC 20114, which produced citric acid and (+)-isocitric acid in the ratio of about 60:40 from n-paraffins, a citrate non-utilizing mutant strain, K-20, and a fluoroacetate-sensitive mutant strain , S-22, were selected on the basis of high citric acid and low (+)-isocitric acid productivity.The mutant strain S-22 showed extremely poor growth in a medium containing sodium citrate as the sole carbon source and extremely high sensitivity to fluoroacetate. The production ratio of citric acid and (+)-isocitric acid by the mutant strain was changed to 97:3, and the yield of the citric acid from n-paraffins, charged to the fermentation medium, reached 145%(w/w). |
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Keywords: | Candida utilis ploidy Cre-loxP system gene disruption uracil auxotroph |
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