利用大肠杆菌工程菌廉价高效生产聚羟基丁酸酯

Efficient polyhydroxybutyrate production from cheap resources by recombinant Escherichia coli

摘要:

利用大肠杆菌生产聚羟基脂肪酸酯是近来国际上生物可降解塑料的研究热点，本研究通过对适宜于聚羟基脂肪酸酯生产的大肠杆菌菌株的选择和碳源利用试验，初步确立了大肠杆菌代谢工程改造生产聚羟基脂肪酸酯的基础。并在此基础上，通过对大肠杆菌磷酸烯醇式丙酮酸葡萄糖转移酶系统的改造和工程菌环境诱导系统的应用，解决了大肠杆菌工程菌无法同时利用多种碳源合成聚羟基脂肪酸酯的难题。发酵试验证明，工程化改造的大肠杆菌利用廉价底物在5 L 发酵罐中分批培养32 h后，菌体终浓度能够达到8.24 g/L，聚羟基脂肪酸酯占细胞干重的84.6

Abstract:

Based on the fermentation analysis of Escherichia coli strains and cheap renewable resources suitable for polyhydroxybutyrate (PHB) production, we constructed a ptsG mutant of Escherichia coli DH5α. Application of E. coli DH5α mutant together with stress-induced system, we could produce PHB efficiently from cheap renewable sugar mixture by the simultaneous consumption of different sugars. Batch fermentation at lab scale (5 liter) showed that E. coli DH5α ΔptsG/pQKZ103 produced PHB from sugar mixture up to 84.6% of cell dry weight in 32 hours; meanwhile, the cell dry weight reached 8.24 g/L.