真养产碱杆菌ATCC17699生产聚β－羟基丁酸摇瓶发酵条件的研究

FERMENTATION CONDITIONS OF POLY HYDROXYBUTYRIC ACID PRODUCTION WITH ALCALIGENES EUTROPHUS ATCC 17699

在摇瓶条件下，首先对Ａ．ｅｕｔｒｏｐｈｕｓ生产ＰＨＢ的一步法和二步法进行了比较研究，然后探讨了Ａ．ｅｕｔｒｏｐｈｕｓ对不同碳源的利用情况，提出了较佳的ＰＨＢ发酵条件，并分析了ＰＨＢ的发酵过程曲线．研究结果表明，本研究采用的Ａ．ｅｕｔｒｏｐｈｕｓ以一步法生产ＰＨＢ较为适宜，其对３种不同碳源的利用能力为：果糖＞丁酸＞葡萄糖；培养基中的丁酸浓度和ｐＨ值对ＰＨＢ发酵的生产指标和动力学参数有较大影响，其最佳值为１．８％和ｐＨ为０．８；最终发酵过程达到细胞于重ρ＝７．２ｇ·Ｌ－１，胞内ＰＨＢ含量ρ＝５．０ｇ·Ｌ－１，ω（ＰＨＢ）占细胞干重７２．２％．

In shake flasks,one-step and two-step fermentation methods were compared for PHB produchon with A. eutrophus and the utilization of carbon sources by A. eutrophus was investigated.Then,relatively optimal PHB fermentation conditions were put forward and time-coures of PHB fermentation was analyzed. The results indicated that one--step fermentation method was more suitable for PHB production with A. eutrophus and its carbon source utilhation ability was: fructose>butyric acid>glucose. The concentration of butyric acid and pH in the medium greatly affected the kinetic parameters and production criteria of PHB formation,and their optimal values were 1. 8% () and pH 8. 0 respectively. The maximal cell dry weight of ρ=7. 2 g. L-1,intracellular ρ(PHB) = 5. 0 g' L-1 and ω(PHB) = 72. 2% in the cells (based on cell dry weight)could be obtained.