Microbial production of unusual biopolyesters

细菌聚羟基烷酸酯（PHAs）是一种细胞内储存材料，可作为生物基塑料使用。最常见的PHA是P（3-羟基丁酸酯），它存在于多种细菌中，产量很高。然而，聚合物的脆性限制了材料的实际应用。本研究通过使用工程聚合物合成系统解决了这一问题，该系统能够合成不寻常的pha。例如，利用工程大肠杆菌有效地生产了等规P（2-羟基丁酸酯）。与化学聚合相比，微生物聚合的优点在于酶促聚合能够从廉价的外消旋前体合成等规聚合物。聚酯具有良好的透明度和柔韧性，不同于传统的pha。乙醇酸基聚酯也是用大肠杆菌生产的。这是细胞内乙醇酸聚合的第一例。

Bacterial polyhydroxyalkanoates (PHAs) are intracellular storage material, which can be used as a biobased plastic. The most common PHA is P(3-hydroxybutyrate), which has been found in a variety of bacteria and produced with good yield. However, the brittleness of the polymer has limited the practical use of the material. This study addressed this problem by using engineered polymer synthetic systems, which are capable synthesizing unusual PHAs. For examples, the isotactic P(2-hydroxybutyrate) was efficiently produced using engineered Escherichia coli. The microbial process had an advantage over the chemical polymerization in that the enzymatic polymerization is capable of synthesizing isotactic polymer from inexpensive racemic precursor. The polyester exhibited excellent transparency and flexibility, which differed from conventional PHAs. The glycolate-based polyester also produced using E. coli. This was the first case for the intracellular polymerization of glycolate.