Naturally degradable bioplastic polyhydroxyalkanoate (PHA) is a promising biopolymer and its physical properties could be changed by introducing of different monomers such as 3-hydroxybutyrate (3HB), 3-hydroxyvalerate (3HV), and 3-hydroxyhexanoate (3HHx). To produce poly(3-hydroxybutyrate-co-3-hydroxyvalerate) P(3HB-co-3HV)) including a high fraction of hydroxyvalerate, we introduced ctfAB into engineered Escherichia coli YJ200 possessing a pLW487 vector containing bktB, phaB, and phaC under control of the trc promoter. To enhance the HV fraction of P(3HB-co-3HV), the optimal concentrations of propionate, which acts as a precursor of 3HV and isopropyl β-D-1-thiogalactopyranoside, were determined and found to be 0.1 mM and 0.3%, respectively. Under the optimized conditions, E. coli, YJ201 produced P(3HB-co-3HV) containing a large amount of 3HV. Comparison with other CoA transferases showed that CtfAB produced relatively lower molecular weight copolymers. This demonstrates the necessity of identifying additional different CoA transferases, because CoA transferase can affect both the monomer fraction and molecular weight of polymers.

天然可降解生物塑料聚羟基链烷酸酯（PHA）是一种很有前途的生物聚合物，可通过引入不同的单体（例如3-羟基丁酸酯（3HB），3-羟基戊酸酯（3HV）和3-羟基己酸酯（3HHx））来改变其物理性质。以产生聚（3-羟基丁酸酯共-3-羟基戊酸酯）P（3HB-共包括羟基戊酸的高分数-3HV）），我们介绍ctfAB成改造的大肠杆菌YJ200具有含有pLW487矢量bktB，PHAB，和的phaC下控制trc启动子。增强P（3HB- co确定作为3HV和异丙基β-D-1-硫代吡喃半乳糖吡喃糖苷前体的丙酸酯的最佳浓度为-3HV），分别为0.1 mM和0.3％。在最佳条件下，大肠杆菌YJ201产生了含有大量3HV的P（3HB- co -3HV）。与其他CoA转移酶的比较表明，CtfAB产生相对较低分子量的共聚物。这证明了鉴定另外的不同CoA转移酶的必要性，因为CoA转移酶可以影响单体部分和聚合物的分子量。