Popis: |
Citric and isocitric acid production were measured in strain A-101 of Yarrowia lipolytica . Product yield on n-hexadecane, including substrate used for cell growth, was in the range of 1·08–1·44 g total acid/g n-hexadecane. The citric acid fraction of total acids synthesized by a particular subculture was in the range 54–64%. Mutants of Y. lipolytica incapable of growth on citrate were isolated at low frequency and were extremely unstable. The difficulty was due to ploidy of our strain as confirmed by determination of nuclear DNA content, average cell diameter, and UV inactivation kinetics. Some mutants were also isolated that excreted predominantly isocitric acid when grown on n-hexadecane. |