Polyhydroxyalkanoates: Safe Biodegradable Plastics for Environment

There are deep concerns about increasing amount of non-degradable plastic in theenvironment. polyhydroxyalkanoates (PHAs) as polyester macromolecule that are naturallyproduced by many species of microorganisms are being considered as a replacement forconventional plastics. While petroleum-derived plastics that take long time to degrade,PHAs can be completely bio-degraded within a year by various microorganisms. Besides,PHA biodegradation results in carbon dioxide and water production that return to theenvironment. Promising genetic engineering methods in microorganisms and plants fieldshave tried to introduce new strategies of PHAs production. This challenge requires severalgenes expression in the host in order to optimize the PHAs synthesis. Although there hasbeen significant progress in recombinant hosts development, some impediments to yieldhigh quantity of PHAs in low cost has been remained. On the other side, PHA synthesis inagricultural crops seems to recieve enough economic interest that makes it a realistic goalto achieve in the future. This paper introduces the characteristics of these biodegradableplastics and also reviews improvement of PHAs synthesis in transgenic plants as well ascurrent barriers in this strategy progress.