含血红蛋白基因(VHb)的铜绿假单胞菌重组菌的构建及鼠李糖脂表达条件的研究

Construction of recombinant strain containing vitreoscilla hemoglobin gene(VHb) of Pseudomonas aeruginosa and its rhamnolipid expressing conditions

将RDR（ribonucleotide diphosphate reductase）启动子驱动下的透明颤菌（Vitreoscillasp．）血红蛋白（Vitreoscilla hernoglobin，VHb）基因的表达载体pSETRDR-VHb转入铜绿假单胞（Pseudamanas aeruginosa）s301菌株中。并对其中阳性转化子AY26菌株进行了鼠李糖脂表达条件的研究。正交实验k（4。）优化培养基，最佳组分为：硫酸镁0．075％、硝酸钠0．5％、清油3mUL、酒石酸钠0．4％。在限碳培养条件下，转化子SY26鼠李糖脂产量达到12．9dL，比对照菌株S301（8．4g／L）提高150％，5L发酵罐放大实验验证，重组菌AY26的表面活性剂产量达到33．12g／L。

In order to construct the Tn5 shuttle plasmid containing vitrcoscilla hemoglobin（VHb） with strong expressed promoter RDR in bacteria, the high level biosuffactants producing strain S301 transudated with VHb gene using the technique of conjugation and chromosome transposition was labelled, selected and identified, then a high level biosuffactant expressed transforrnants was obtained. By orthogonal test, the optimized substrate components were 0. 075% of MgSO4 ＂7H2O, 0.5% of sodium nitrate, 0.4% of sodium tartrate, 3 mL/L of bean oil. The result showed that the yield of rhamnolipid produced by SY26 reached 12.9 g/L, higher than that by S301 （8.4 g/L） and the yield of biosuffactant produced by AY26 in 5 L fermenter was as high as 33.12 g/L.