ABSTRACT
Plastics have unquestionably been the miracle materials and attained an inimitable place in contemporary material technology. The exploration for such degradable polymers has focused for the introduction of three categories of degradable plastic materials: semi-biodegradable, photodegradable, and completely biodegradable. Biodegradable plastics are polylactides, polyhydroxyalkanoates (PHAs), polysaccharides, aliphatic polyesters, co-polymers and/or blends of the above. Of all these, the microbially-synthesized PHAs offer ample potential. PHAs are a group macromolecules accumulated as water insoluble storage compounds in the cytoplasm of microbial cells. In photoautotrophic host system, synthesis of PHAs in agricultural crops has been regarded as a promising alternative. PHA polymers have gained substantial interest as a result of rising environmental concerns over conventional plastics. Despite the basic attractiveness as an alternate for petroleum-derived polymers, the foremost obstacle facing triumphant commercialization of PHAs is the high price of bacterial fermentation, which brought photoautotrophic hosts and alternate inexpensive substrates into focus for low-cost PHAs production.
