运用试验读者设计方法提高胞外杂合β-葡聚糖酶在重组大肠杆菌中的表达

• 作 者: 卢英华 邓旭 程志敬 李清彪 刘刚
• 机 构: Department of Chemical and Biochemical Engineering,The Key Laboratory for Chemical Biology of Fujian
• 出 处: 中国化学工程学报（英文版）
• 发表日期: 2004年期
• 关键词: β-glucanase recombinant Escherichia coli statistical methodology medium optimiza

A genetically engineered Escherichia coli JM109 harboring pLF3 was used to produce a hybrid extracellular β-glucanase. Starting with enzyme production medium, glycerol and yeast extract combined with NaNO3 were screened to be the most suitable carbon and nitrogen source, respectively. Analysis of six components of the enzyme production medium by employing statistical optimization methods such as Plackett-Burman design and steepest ascent showed that yeast extract was the only significant variable and its best concentration for enzyme production was 12g·L-1. After optimization of the medium, 297.71U·ml-1 of β-glucanase activity in the medium and 352350U·g-1 of β-glucanase selectivity could be obtained, which were 14 and 72 folds higher than those obtained from original medium, respectively. Even higher enzyme activities were achieved by batch cultivations in a conventional stirred bioreactor on the optimized medium.