Microbial production of unusual biopolyesters

细菌聚羟基脂肪酸酯（PHAs）是一种细胞内储存物质，可用作生物基塑料。最常见的PHA是P（3-羟基丁酸酯），其已在多种细菌中发现并以良好的产率产生。然而，聚合物的脆性限制了材料的实际应用。这项研究通过使用工程聚合物合成系统解决了这个问题，该系统能够合成不寻常的PHA。例如，全同立构P（2-羟基丁酸酯）使用工程化大肠杆菌有效地产生。微生物法与化学聚合法相比，酶促聚合法能够从廉价的外消旋前体合成全同立构聚合物。该聚酯表现出优异的透明度和柔韧性，这不同于传统的PHA。乙醇酸酯基聚酯也使用E.杆菌这是乙醇酸盐在细胞内聚合的第一例。

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.