Establishment of the all biosynthetic system for new monomers-contained biopolymers as a basis for enzyme evolutionary engineering

建立了高性能乳酸（LA）聚合物的微生物生产体系。这种新的微生物工厂可以由可再生生物质资源驱动。该系统的一个突破是“la聚合酶（LPE）”的发现。LPE是通过对微生物聚合物PHA合成酶的工程研究而产生的。以葡萄糖为原料，引入LPE基因，在大肠杆菌中一锅法合成了la基聚合物。通过代谢工程和酶工程的结合，将聚合物中的LA组分从6%富集到47%。此外，la基聚合物与对应的均聚物PLA和PHB具有不同的性能。

Microbial production system for lactate (LA) polymers with high performances has been established. This new microbial factory can be driven by renewable biomass resources. A break-through of this system was a discovery of "LA-Polymerizing Enzyme (LPE)". LPE was created through the study on the engineering of microbial polymer PHA synthase. LA-based polymer was synthesized as an one-pot manner in Escherichia coli by introduction of the LPE gene from glucose. Also, LA fraction in the polymer has been enriched up to 47% from 6% by combination of metabolic and enzyme engineering. Furthermore, LA-based polymers exhibited distinguishable properties from the counterpart homopolymers, PLA and PHB.