Effect of Vitreoscilla Hemoglobin Gene（vgb） Expression on Growth and Metabolish of Streptomyces venezuelae var. qinlingensis and Its Effect on Zuelacmycin Valence
摘要委内瑞拉链霉菌秦岭变种(Streptomyces venezuelae var. qinlingensis)是瑞拉菌素(Zuelacmycin)的产生菌，为进一步探讨透明颤菌血红蛋白基因（vgb）表达对秦岭变种以及瑞拉菌素产率的影响，利用红霉素抗性基因启动子在委内瑞拉链霉菌秦岭变种中表达vgb基因，并在5 L发酵罐中研究了工程菌株与原始菌株的生长代谢特性及瑞拉菌素的效价。结果表明：在高溶氧条件下vgb基因表达并未对菌丝体生长和氨基氮的消耗产生明显的影响，但提高了对还原糖的消耗，工程菌株发酵瑞拉菌素的效价比原始菌株降低8%；在低溶氧条件下，vgb基因的表达可促进菌丝体的生长和次级代谢，并提高了还原糖的消耗，工程菌株发酵瑞拉菌素的效价比原始菌株提高45%。本研究首次利用VHb蛋白基因表达提高了委内瑞拉链霉菌秦岭变种对氧的利用率和瑞拉菌素的效价，为进一步推动瑞拉菌素工业化生产提供基础资料。
Abstract：Streptomyces venezuelae var. qinlingensis is a Zuelaemycin producting strain. For studying on effect of Vitreoscilla hemoglobin gene（vgb） expression in Streptomyces venezuelae var. qinlingensis and on Zuelacmycin production, it expressed through promoter of erythromycin resistance gene, characteristics of engineered strain and original strain growth and metabolism and Zuelaemycin valence were studied in 5 L fermenter. The result showed that: In high dissolved oxygen concentrations, the growth rate and ammonia nitrogen expenditure of engineered strain was slightly lower than that of the original strain, but utilization rate of starch was higher than that of the original strain, Zuelaemycin valence of engineered strain was decreased by 8% than that of original strain; in low dissolved oxygen concentrations, espression of hemoglobin enhanced growth, secondary metabolish and utilization rate of starch, and Zuelaemycin valence of engineered strain was more 45% than that of original strain.
