Methods for engineering transgenic organisms that synthesize polyhydroxyalkanoates (PHAs) containing 3-hydroxyhexanoate as comonomer have been developed. These processes are based on genetically engineered bacteria such as Escherichia coli or in plant crops as production systems which include PHA biosynthetic genes from PHA producers. In a preferred embodiment of the method, additional genes are introduced in wild type or transgenic polyhydroxybutyrate (PHB) producers, thereby creating new strains that synthesize 3HH monomers which are incorporated into PHAs. The 3HH monomer preferably is derived in microbial systems using butanol or butyrate as feedstocks, which are precursors of 3-hydroxyhexanoyl-CoA. Pathways for in vivo production of butyrol-CoA specifically encompassing butyryl-CoA dehydrogenase activity are provided.
目前已开发出可合成以 3-hydroxyhexanoate 为单体的聚羟基烷酸酯(PHA)的转
基因生物的工程方法。这些方法以
基因工程细菌(如大肠杆菌)为基础,或以植物作物为生产系统,其中包括来自 PHA 生产者的 PHA
生物合成
基因。在该方法的一个优选实施方案中,在野生型或转
基因聚羟基
丁酸(
PHB)生产者中引入额外的
基因,从而产生合成 3HH 单体的新菌株,这些单体被掺入 PHA 中。3HH 单体最好在以
丁醇或
丁酸为原料的微
生物系统中产生,它们是 3-hydroxyhexanoyl-CoA 的前体。提供了体内生产丁酰-CoA 的途径,特别是包含丁酰-CoA 脱氢酶活性的途径。