Polyhydroxyalkanoates (PHA) have found widespread medical applications due to their biocompatibility and biodegradability, while further chemical modification requires functional groups on PHA. Halomonas bluephagenesis, a non-model halophilic bacterium serving as a chassis for the Next Generation Industrial Biotechnology (NGIB), was successfully engineered to express heterologous PHA synthase (PhaC) and enoyl coenzyme-A hydratase (PhaJ) from Aeromonas hydrophila 4AK4, along with a deletion of its native phaC gene to synthesize the short chain-co-medium chain-length PHA copolymers, namely poly(3-hydroxybutyrate-co-3-hydroxyhexanoate), poly(3-hydroxybutyrate-co-3-hydroxyhex-5-enoate) and poly(3-hydroxybutyrate-co-3-hydroxyhexanoate-co-3-hydroxyhex-5-enoate). After optimizations of the expression cassette and ribosomal binding site combined with introduction of endogenous acyl-CoA synthetase (fadD), the resulting recombinant strain H. bluephagenesis TDR4 achieved a remarkably high 3-hydroxyhexenoate (3HHxE) molar ratio of 35% when grown on glucose and 5-hexenoic acid as co-substrates. The total ratio of side chain consisting of 3HHx and 3HHxE monomers in the terpolymer can approach 44 mol%. H. bluephagenesis TDR4 was grown to a cell dry mass (CDM) of 30 g/L containing approximately 20% poly(3-hydroxybutyrate-co-22.75 mol% 3-hydroxy-5-hexenoate) in a 48-h of open and unsterile fermentation with a 5-hexenoic acid conversion efficiency of 91%. The resulted functional PHA containing 12.5 mol% 3-hydroxy-5-hexenoate exhibits more than 1000% elongation at break. The engineered H. bluephagenesis TDR4 can be used as an experimental platform to produce functional PHA.

聚羟基链烷酸酯（PHA）由于其生物相容性和生物降解性而在医学上得到了广泛应用，而进一步的化学修饰则需要PHA上的官能团。Halomonas bluephagenesis是一种无模型的嗜盐细菌，是下一代工业生物技术（NGIB）的底盘，已成功工程改造以表达嗜水气单胞菌4AK4的异源PHA合酶（PhaC）和烯酰辅酶A水合酶（PhaJ），以及其天然的缺失的phaC基因合成短链-共-medium链长的PHA共聚物，即聚（3-羟基丁酸酯共-3-羟基己酸酯），聚（3-羟基丁酸酯共-3-羟基己-5-烯酸甲酯）和聚（3-羟基丁酸酯共-3- hydroxyhexanoate-共-3-羟基己-5-烯酸乙酯）。之后的表达盒和核糖体结合位点与引入内源性酰基-CoA合成酶（的组合的优化的fadD），将得到的重组菌株H. bluephagenesis在葡萄糖上生长时TDR4取得了显着高的3- hydroxyhexenoate（3HHxE）的35％的摩尔比和5-己酸作为共底物。三元共聚物中由3HHx和3HHxE单体组成的侧链的总比例可接近44 mol％。蓝生H.bluephagenesis TDR4生长到细胞干重（CDM）为30 g / L，其中包含约20％的聚（3-羟基丁酸酯-co在48小时的开放式和非无菌发酵中，其-22.75 mol％3-羟基-5-己酸（5-羟基5-己酸）的5-己酸转化率为91％。所得的含有12.5mol％的3-羟基-5-己烯酸酯的功能性PHA表现出超过1000％的断裂伸长率。经工程改造的蓝球菌TDR4可用作生产功能性PHA的实验平台。