中国生物工程杂志

The influence of dissolved oxygen (DO) concentration, varied from10% (of air saturation) to 60%, on glycerol production by Candida glycerinogenes in the batch fermentation was investigated by using the chemically defined medium. The results showed that it was suitable for glycerol production by C. glycerinogenes at DO concentration of 30%, the glycerol concentration, yield and productivity were 120.7 g/L, 0.575 g/g and 1.69 g/(L•h), respectively, while the glycolytic by-products formation was the least. At DO concentration of 10%, the “Pasteur effect” arose during the whole fermentation process, so the glycolytic by-products could be kept a high level. During the rapid growth phase, the cells of C. glycerinogenes could gradually transit their anaerobic fermentation to aerobic metabolism and reduce the formation of glycolytic by-products when the DO concentration increased from 10 % to 60 %. However, the oxygen consumption of cells decreased sharply during the steady growth stage. With increasing DO concentration, the amounts of ethanol and acetic acid were gradually decreased. Logistic equation, Luedeking-Piret equation and Luedeking-Piret-Like equation were successfully applied to estimate the kinetics of cell growth, glycerol production and glucose consumption, respectively, under diverse DO concentrations.