Plastics Completely Synthesized by Bacteria: Polyhydroxyalkanoates

Abstract

Many years of research efforts have led to the large-scale production of poly[(R)-3-hydroxybutyrate], copolymers of (R)-3-hydroxybutyrate and (R)-3- hydroxyvalerate, copolymers of (R)-3-hydroxybutyrate and 4-hydroxybutyrate, as well as copolymers of (R)-3-hydroxybutyrate and (R)-3-hydroxyhexanoate. A small amount of medium-chain-length polyhydroxyalkanoate (PHA) has also been reported to have been produced. Worldwide, 24 companies are known to be engaged in PHA production and applications. Beginning from 2009, more than 10,000 PHA will be available on the market, and new applications are expected to be developed when large amounts of PHA are available for exploitation. In the future, the large scale of PHA applications will be dependent on the production cost. Therefore, it is very urgent to develop low-cost PHA production technology, including those of continuous and nonsterile processes based on mixed cultures and mixed substrates.