Microbial production of biopolyesters-polyhydroxyalkanoates

Polyhydroxyalkanoate, abbreviated to PHA, is a family of polyesters produce d by a variety of microorganisms. Over 90 PHA with various structure variat ions have been reported and the number is still increasing. Some interestin g physical properties of PHA such as piezoelectricity, nonlinear optical ac tivity and biocompatibility, offer promising applications in areas such as tissue engineering and drug delivery. Worldwide there have been many attemp ts to produce PHA as biodegradable plastics using various microorganisms ob tained from screening natural environments, genetic engineering and mutatio n methods. It has been found that PHA synthesis is a common phenomenon of b acteria inhabiting in various locations, especially oil-contaminated soils. Bacterial strains capable of synthesizing PHA with various monomers have b een identified from oil-contaminated soils, and PHA production strains capa ble of rapid growth and rapid PHA synthesis on molasses substrate have also been found on molasses contaminated soil. It seems that the combination of novel properties and lower cost will allow easier commercialization of PHA .