Recent advances in the knowledge of the metabolism of bacterial polyhydroxyalkanoic acids and potential impacts on the production of biodegradable thermoplastics

Bacteria are able to synthesize a wide variety of different thermoplastic polyhydroxyalkanoic acids (PHA). The physiology of PHA metabolism has been studied in most detail in the aerobic hydrogen bacterium Alcaligenes eutrophus . Strains of this bacterium are already used for the production of biodegradable polyesters on a technological scale. The current knowledge on the pathways for PHA synthesis, on the genes essential for PHA biosynthesis and on genes affecting the accumulation of PHA in this bacterium will be reviewed.