Microbial and Enzymatic Technology Group, Bioprocess Center, Biotechnology Research Institute, National Research Council Canada, 6100 Royalmount Avenue, Montreal, Quebec, H4P 2R2, Canada.
Front Biosci (Landmark Ed). 2010 Jan 1;15(1):93-121. doi: 10.2741/3609.
Polyhydroxyalkanoates (PHAs) serve numerous bacteria as storage compounds. It is generally believed that under unbalanced growth conditions, n-hydroxyalkanoates are synthesized inside the bacterial cells, polymerized to polyesters, and densely packed in granules. In the absence of extracellular carbon, the internally stored PHAs are depolymerized and consequently metabolized to enable cell maintenance and reproduction. However, some bacteria exhibit growth associated production and degradation of PHAs as part of the cell sustainment. This natural production and degradation cycle indicates that PHAs possess biodegradability and may have biocompatibility properties. Since the discovery that some bacteria can incorporate 3-hydroxyalkanoates bearing functional groups from related substrates, research has led to structural diversification of PHAs by biosynthesis and chemical modifications. A commonly applied route for tailoring PHAs is their in situ functionalization by biosynthetically producing side chains with terminal double bonds followed by chemistry. Non-functionalized PHAs can also be activated by surface modification techniques. The resulting tailor-made structural and material properties have positioned polyhydroxyalkanoates well to contribute to the manufacturing of second and third generation biomaterials.
聚羟基烷酸酯（PHAs）是许多细菌的储存化合物。一般认为，在不平衡的生长条件下，n-羟烷酸在细菌细胞内合成，聚合形成聚酯，并在颗粒中紧密堆积。在没有细胞外碳源的情况下，内部储存的 PHAs 被解聚，并因此代谢以维持细胞的维持和繁殖。然而，一些细菌表现出与生长相关的 PHAs 的产生和降解，作为细胞维持的一部分。这种自然的生产和降解循环表明 PHAs 具有生物降解性，并可能具有生物相容性。自从发现一些细菌可以将含有来自相关底物的官能团的 3-羟基烷酸掺入其中以来，通过生物合成和化学修饰，研究已经导致 PHAs 的结构多样化。一种常用的定制 PHAs 的方法是通过生物合成产生带有末端双键的侧链，然后进行化学修饰。非官能化的 PHAs 也可以通过表面改性技术进行激活。由此产生的定制结构和材料性能使聚羟基烷酸酯在制造第二代和第三代生物材料方面具有很好的地位。
