1,3-丙二醇(1,3-PD)是一种重要的化工原料,其最重要的用途是作为合成聚酯PTT的单体.由于微生物发酵法生产1,3-PD具有操作简单,不易产生有毒副产物等特点,已得到广泛关注.本研究在前期工作的基础上,分别获得了来源于肺炎克雷伯氏菌的甘油脱水酶编码基因dhaB和来源于大肠杆菌的1,3-PD氧化还原酶同工酶编码基因yqhD,利用温控表达载体pBV220串联构建了重组质粒pBV220-yqhD-dhaB,将其转化大肠杆菌得到产1,3-丙二醇温控重组大肠杆菌JM109(pBV220-yqhD-dhaB).该重组菌在LB培养基中,30℃好氧培养12h至对数生长中期,再经42℃好氧诱导发酵4h,测得胞内甘油脱水酶和1,3-丙二醇氧化还原酶同工酶的酶活力分别达到260U/mg蛋白和140U/mg蛋白;在含甘油40g/L的发酵培养基中,30oC好氧培养12h至对数生长中期,再经42℃好氧诱导发酵4h,测得发酵液中1,3-PD含量为8.5g/L.这将为进一步构建基因工程菌生产1,3.PD打下坚实的基础.图6表1参18
1,3-propanediol is one of the most important industrial chemicals for its properties. 1,3-PD production has attracted attention as an important monomer to synthesize a new type of polyester, polytrimethyleneterephthalate(PTT). Microbial conversion of glycerol to 1,3-PD is particularly attractive in that the process is relatively easy and does not generate toxic byproducts. In our previous study, gene dhaB encoding for glycerol dehydratase from KlebsieUa pneumoniae and gene yqhD encoding for 1,3-propanediol oxidoreductase isoenzyme from Escherichia coli were cloned, respectively. In this study, gene dhaB and gene yqhD were transferred into temperature control expression vector pBV220 to construct a temperature control recombinant E. coli JM109 (pBV220-yqhD-dhaB). The recombinant E. coli was incubated at 30℃ for 12 h, and then incubated at 42℃ for 4 h under aerobic conditions, the specific enzymatic activities of glycerol dehydratase and 1,3-propanediol oxidoreductase isoenzyme were found reaching 260 u/mg protein and 140 u/mg protein, and the yield of 1,3-propanediol from the fermentation broth with 40 g/L glycerol by the recombinant E. coli could reached 8.5 g/L. This study will provide the basis for further construtting recombinant strains capable of producing 1,3-PD. Fig 6, Tab 1, Ref 18