budR表达水平对克雷伯氏菌甘油代谢的影响

Influence of expression level of budR on glycerol metabolism of Klebsiella peneumoniae

通过过量表达和反义RNA抑制改变budR表达水平,考察budR表达水平对克雷伯氏菌甘油代谢的影响。过表达budR使得Bud B和Bud C的酶活提高了48.7%和69.7%,1,3-丙二醇产量降低了12.6%,2,3-丁二醇含量增加了73.3%,同时乙酸含量显著降低。反义RNA抑制budR表达后,Bud B和Bud C酶活分别降低了56%和78%,重组菌的生物量、2,3-丁二醇(BDO)、乙酸、乳酸等均表现为略有降低,1,3-丙二醇含量达到23.4g/L,提高约10%。上述结果进一步丰富了budR基因在调控bud操纵子的表达水平、2,3-丁二醇合成及克雷伯氏菌甘油代谢中的作用,为后续代谢改造克雷伯氏菌合成1,3-丙二醇提供了新的思路。

In this study,the expression level of budR was enhanced and repressed by overexpression and synthetic antisense RNA,respectively. The Bud B and Bud C activities were increased by 48. 7% and 69. 7%,respectively,by overexpression of budR. The titer of 1,3-propanediol was reduced by 12. 6%. The concentration of 2,3-butanediol was increased by 73. 3%. Meanwhile,the concentration of acetate was significantly increased. The Bud B and Bud C activities were repressed by 56% and 78%,respectively,after introduction of antisense RNA of budR. The 1,3-propanediol titer reached 23. 4 g / L with the improvement by 10%. However,there were no significant changes of the concentrations of 2,3-butanediol and other byproducts after the introduction of the antisense RNA of budR. The results reported here provided new information about the effect of budR on the regulation of bud operon,2,3-butanediol synthesis and glycerol metabolism of Klebsiella peneumoniae.