【摘要】 为解决聚 β-羟基丁酸酯 (PHB)生产过程中的高成本问题 ,构建了具有高溶氧利用能力及可自动裂解破壁的PHB高产基因工程菌 VG1(p TU14)。对该重组菌的葡萄糖耐受能力、乙酸的辅助同化作用及较廉价的淀粉水解液替代葡萄糖的可行性等进行了研究。该重组菌可以在初糖浓度2 0 0 g/ L 的培养基中良好生长 ;无机氮源乙酸铵可同时提供乙酸作为辅助碳源 ;采用淀粉水解液可以完全替代葡萄糖 ,发酵结束时菌体生长和 PHB积累均提高 ,还原糖利用率也可达到 99%以上。更多还原

【Abstract】 To reduce the high cost of poly β hydroxybutyrate (PHB) production, Vitreoscilla hemoglobin gene (vgb), lytic genes with the S amber mutation of the phage lambda (S RRz) and PHB biosynthetic genes (phbCAB) were introduced into the same cell of E.coli JM105 by cloning. A novel recombinant multi functional strain VG1 (pTU14) was constructed which had high oxygen uptake, inducible autolysis and high PHB accumulation. The novel strain could even grow in broth with a high initial glucose concentration of 200g/L. Ammonium acetate, which was the inorganic nitrogen in the medium, was also a carbon source, co promoting the PHB accumulation in the novel strain. In addition, the less expensive starch hydrolysate could be substituted for glucose, with increased cell growth, PHB accumulation and 99% of the consuming yield of the reduced dextrose in the starch hydrolysate.更多还原