Physiology and molecular genetics of poly(β‐hydroxyalkanoic acid) synthesis in Alcaligenes eutrophus

SummaryThe Alcaligenes eutrophus genes for β‐ketothiolase, NADPH‐dependent acetoacetyl‐CoA reductase and poly(β‐hydroxybutyric acid) synthase (PHB synthase) which comprise the three‐step PHB‐biosynthetic pathway, were cloned. Molecular studies revealed that these genes are organized in a single operon. The A. eutrophus PHB‐biosynthetic genes are readily expressed in other bacteria, and DNA fragments harbouring the operon can be used as a cartridge to confer to other bacteria the ability to synthesize PHB from acetyl‐CoA. The biochemical and physiological capabilities of A. eutrophus for the synthesis of a wide variety of polyhydroxyalkanoates are discussed.