野油菜黄单胞菌中gumD基因的过表达对产黄原胶的影响

Effect of by overexpressing gumD in Xanthomonas campestris on the xanthan gum

目的在野油菜黄单胞菌58(Xc58)中过量表达产胶基因gumD,提高黄原胶发酵产量和质量。方法通过PCR扩增、重组质粒构建、三亲本接合等方法,将重组质粒pBBR-gumD转入原始菌Xc58。结果工程菌与原始菌相比,黄原胶产量提高11.19%,黏度提高6.31%,重均分子质量提高20.21%,乙酰基含量提高77.07%,丙酮酸含量下降6.34%。结论改造后的菌株的黄原胶发酵产量和质量都较原始菌株有所提高。

Purpose To improve the yield and quality of xanthan gum by overexpressing gumD in Xanthomonas campestris 58（Xc58）.MethodsBy PCR amplification,plasmid construction,triparental conjugation and other methods,pBBR-gumD was transformed into the original strain Xc58.ResultsCompared with Xc58,the recombinant strain Xc58-D has increased by 11.19% in the yield of xanthan gum,by 6.31% increased in viscosity,by 20.21 % increased in molecular weight,and by 77.07% increased in acetyl content,but 6.34% decreased in pyruvate content.ConclusionThe recombinant strain has a higher yield and improves the quality of xanthan gum.