Microbial production of biopolyesters-polyhydroxyalkanoates

Polyhydroxyalkanoate, abbreviated to PHA, is a family of polyesters produced by a variety of microorganisms. Over 90 PHA with various structure variations have been reported and the number is still increasing. Some interesting physical properties of PHA such as piezoelectricity, nonlinear optical activity and biocompatibility, offer promising applications in areas such as tissue engineering and drug delivery. Worldwide there have been many attempts to produce PHA as biodegradable plastics using various microorganisms obtained from screening natural environments, genetic engineering and mutation methods. It has been found that PHA synthesis is a common phenomenon of bacteria inhabiting in various locations, especially oil-contaminated soils. Bacterial strains capable of synthesizing PHA with various monomers have been identified from oil-contaminated soils, and PHA production strains capable 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.