[Progress on the biosynthesis of medium-chain-length polyhydroxyalkanoates by microorganisms]

Polyhydroxylkanoates(PHAs) are a class of polyesters produced as reserve materials by a large number of microorganisms under metabolic stress. The most fascinating feature of PHAs is its degradability, and which is supposed to take place of the traditional plastics made from petroleum in the future. PHAs are divided into two classes: short-chain-length PHAs(scl-PHAs) and medium-chain-length PHAs. mcl-PHAs is more welcome owing to its more wide crystallinity and higher extension to break than scl-PHAs, especially when some kind of new functional groups were incorporated into the side chain of the polyester. Since Psedumonas oleovorans is the most typical microorganism to produce mcl-PHAs, here the author summarized how P. oleovorans synthesize the mcl-PHAs and the production of mcl-PHAs by fermentation and give some of the idea about the future research of this field.