Korean Minjok Leadership Academy, 600 Bongwha-ro, Anheung-myeon, Hoengseong-gun, Gangwon-do 225-823, Republic of Korea.
Microb Cell Fact. 2013 May 28;12:54. doi: 10.1186/1475-2859-12-54.
Numerous microorganisms accumulate polyesters classified as polyhydroxyalkanoates (PHAs) as carbon and energy storage material when the growth condition is unfavorable in the presence of excess carbon source. Natural PHAs typically consist of various (R)-hydroxycarboxylic acids, and exhibit different material properties depending on the monomer composition. Such diversity comes from different metabolic pathways operating in the cell, and thus generating different monomers. Even more diverse PHAs can be produced by metabolically engineered microorganisms, which leads to the biosynthesis of non-natural polyesters containing lactate as a monomer. In order to make PHAs as useful polymers in our daily life, their production cost should be significantly lowered and material properties should be compatible with those produced by petrochemical industries. Metabolic engineering can address these issues by developing microbial strains capable of producing PHAs of desired material properties with high productivity and yield from inexpensive carbon sources. This commentary aims at peeking into the future of PHAs, focusing on the possible metabolic engineering strategies to be taken to achieve these goals.
当生长条件不利且存在过量碳源时，许多微生物会积累被归类为聚羟基烷酸酯 (PHA) 的聚酯，将其作为碳和能量储存物质。天然 PHA 通常由各种 (R)-羟基羧酸组成，并且根据单体组成表现出不同的材料性能。这种多样性来自于在细胞中运作的不同代谢途径，从而产生不同的单体。通过代谢工程微生物还可以生产出更多样化的 PHA，从而导致含有乳酸作为单体的非天然聚酯的生物合成。为了使 PHA 成为我们日常生活中有用的聚合物，其生产成本应大幅降低，并且其材料性能应与石化工业生产的产品相兼容。代谢工程可以通过开发能够从廉价碳源以高产率和高得率生产具有所需材料性能的 PHA 的微生物菌株来解决这些问题。本评论旨在展望 PHA 的未来，重点关注为实现这些目标可能采取的代谢工程策略。
