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›› 2008, Vol. 8 ›› Issue (1): 109-114.

• 生化工程专栏 • 上一篇    下一篇

Bacillus macorous合成g-CGT酶过程中阻遏效应与指数流加发酵

王峰,堵国成,顾正彪,陈坚   

  1. 江南大学化学与材料工程学院
  • 出版日期:2008-02-20 发布日期:2008-02-20

Application of Exponential Fed-batch Model for Reducing Repression during g-CGTase Production by Bacillus macorous

WANG Feng,DU Guo-cheng,GU Zheng-biao,CHEN Jian   

  1. School of Chemical and Material engineering, Southern Yangtze University
  • Online:2008-02-20 Published:2008-02-20

摘要: 考察了不同搅拌转速、pH值和温度条件下,细胞生长、g-CGT酶产量与培养液中直链麦芽低聚糖积累的关系. 细胞的最大比生长速率为0.2 h-1是g-CGT酶产量从增长到下降的拐点. 发酵液中直链麦芽低聚糖的存在能促进细胞生长并引起胞内的FDP, ATP和G6P含量增加,而对产酶显示出分解代谢阻遏效应. 指数流加结果显示,通过限制细胞的比生长速率,可将阻遏作用控制在较低水平,酶产量得到了大幅度提高,是分批发酵酶产量的7.9倍,达到2565 U/mL.

关键词: g-CGT酶, 直链麦芽低聚糖, 分解代谢阻遏, 最大比生长速率, 指数流加

Abstract: The Influences of agitation speed, temperature and pH-controlling strategy on cell growth, linear maltooligosaccharides accumulation in broth and g-CGTase yield were investigated in the batch culture of Bacillus macorous. When the maximal value of specific growth rate was higher than 0.2 h-1, the g-CGTase yield decreased. The linear maltooligosaccharides generated during fermentation can promote the cell growth and elevate the intracellular contents of FDP, ATP and G6P, which demonstrated a repression effect on the production of g-CGTase. Hence, the exponential feeding mode of nutrients was carried out to control the catabolite repression by limiting the specific cell growth rate. The highest yield of g-CGTase obtained in fed-batch was 2565 U/mL, which was 7.9 times of that in batch fermentation.

Key words: g-CGTase, linear maltooligosacchaeides, catabolite repression, maximal specific growth rate, exponential feeding