| Abstract: | Many bacteria have been found to synthesize a family of polyesters termed polyhydroxyalkanoate, abbreviated asPHA. Some interesting physical properties of PHAs such as piezoelectricity, non-linear optical activity, biocompatibility andbiodegradability offer promising applications in areas such as degradable packaging, tissue engineering and drag delivery.Over 90 PHAs with various structure variations have been reported and the number is still increasing. The mechanicalproperty of PHAs changes from brittle to flexible to elastic, depending on the side-chainlength of PHA. Many attempts havebeen made to produce PHAs as biodegradable plastics using various microorganisms obtained from screening naturalenvironments, genetic engineering and mutation. Due to the high production cost, PHAs still can not compete with the non-degradable plastics, such as polyethylene and polypropylene. Various processes have been developed using low cost rawmaterials for fermentation and an inorganic extraction process tbr PHA purification. However, a super PHA production strainmay play the most critical role for any large-scale PHA production. Our recent study showed that PHA synthesis is acommon phenomenon among bacteria inhabiting various locations, especially oil-contaminated soils. This is very importantfor finding a suitable bacterial strain for PHA production. In fact, PHA production strains capable of rapid growth and rapidPHA synthesis on cheap molasses substrate have been found on molasses contaminated soils. A combination of novelproperties and lower cost will allow easier commercialization of PHA for many applications. |
