Recent advances in polyhydroxyalkanoate production by bacterial fermentation: mini-review

Poly(3-hydroxybutyrate) [P(3HB)] and other polyhydroxyalkanoates (PHAs) hav e been drawing much attention as biodegradable substitutes for conventional nondegradable plastics. For the economical production of P(3HB), various b acterial strains, either wild-type or recombinant, and new fermentation str ategies were developed for the production of P(3HB) with high concentration and productivity. To reduce the cost of carbon substrate, several processe s for P(3HB) production from cheap carbon sources were also developed. P(3H B) can now be produced to a content of 80% of cell dry weight with the prod uctivity greater than 4 g/l per h. Fermentation strategy was also developed for the efficient production of medium chain length PHA by high cell densi ty culture. With all these advances, P(3HB) and PHAs can be produced by bac terial fermentation at a cost (ca. $2/kg) similar to that of other biodegra dable polymers under development. (C) 1999 Elsevier Science B.V. All rights reserved.