科研之友
微信
新浪微博
Facebook
分享链接
摘要
Sustained oscillations have been observed in cell growth and glycerol metabolism by Klebsiella pneumoniae during long-term continuous cultivations under anaerobic conditions. However, the oscillation behavior of glucose-glycerol co-fermentation under micro-aerobic conditions has yet not been studied. In this study, the unclear mechanism of oscillation was investigated by using different substrates including glycerol, glucose, and mixtures of glycerol and glucose. A large perturbation of substrate concentration was operated to study the dynamic behavior of continuous fermentation by K. pneumoniae DSM 2026 under micro-aerobic conditions. Oscillations occurred when 80 g of glycerol l(-1) was used as single carbon source or co-substrate with 35 g of glucose l(-1), whereas no oscillation was observed when glucose was used alone. During the oscillation phases, parameters periodically passed maxima and minima at a relatively constant time interval, and the period of oscillation was 10-16 h. The comparison between glycerol and glucose metabolism revealed that a potential mechanism of oscillation lies in the accumulation of 3-hydroxypropionaldehyde, which is toxic to cell growth.
