dhaBCE基因与yqhD基因串联表达载体的构建及其生物转化甘油

将来自于肺炎克雷伯氏杆菌的甘油脱水酶基因插入到质粒pET28(a+) -yqhD的上游，并用SD序列隔开，串联构建重组质粒pET28(a+)dhaBCE-yqhD，转化到大肠杆菌E.coli novablue中进行共表达。结果显示：含有pET28(a+) dhaBCE-yqhD的重组菌在28℃条件下，IPTG诱导16h后，甘油脱水酶和yqhD氧化还原酶的酶活力分别达到35 U/ mg和 82 U/ mg ，而对照组检测不到甘油脱水酶酶活；当甘油浓度为55g/L，产物1,3-PD的产量可达39g/L；甘油浓度过量不利于产物合成，且产物1，3-丙二醇对合成反应具有一定的抑制作用。

Construction of dhaBCE and yqhD co-expression vector and its biotransformation of glycerol

DhaBCE from Klebsiella.pneumoniae was inserted into the yqhD upriver in the plasmid pET28(a+)-yqhD. The recombinant plasmid pET28(a+)dhaBCE-yqhD harboring the genes encoding dhaBCE and yqhD with a Shine-Dalgarno (SD) sequence was transformed into E. coli novablue to be co-expression. The results showed that after 16 hours calculated following the addition of inducer IPTG at induce temperature 28℃, the enzyme activity of glycerol dehydratase and yqhD. oxidoreductase in recombined strain could arrive 35 U/ mg and 82 U/ mg, individually, higher than the wild type. The yield of 1, 3-PD arrived at 39g/L when 55g/L of substrate glycerol was added in the fermentation culture. Excessive glycerol badly influence produce formation and inhibition of product on 1, 3-propenediol biotransformation existed.