POLYHYDROXYALKANOATES: BIOSYNTHESIS TO COMMERCIAL PRODUCTION- A REVIEW

Abstract

The global increase in petroleum prices and the growing concern about the harmful effects of petroleum based plastics has led to a shift from a petroleum based economy to a natural feedstock based economy. One of the major outcomes of this economy shift is the global acceptance of biobased plastics such as Polyhydroxyalkanoates (PHAs) as a replacement for traditional plastics. Even though PHAs have been described as useful polymers due to their intrinsic biodegradability and biocompatibility, the high price has limited their application significantly. The raw material cost has been known to contribute significantly to the manufacturing cost of PHA. Production of PHAs using agro-industrial residues offers an alternative use of low-cost feedstock to produce materials with appropriate physicochemical properties to be used in a broad range of applications. Therefore, much research has been carried out using renewable cheap raw materials such as molasses, lignocellulosic wastes, sewage, industrial by-products, whey etc. to replace the expensive commercial medium, which should reduce the overall production cost. This review highlights various microorganisms, substrates and fermentation strategies used for economical production of PHA.