Hasan Diba - M. Sc. Biology Trend in Microbiology, Department of Biology, Science and Research branch, Islamic Azad University, Tehran, Iran
Reza Seifi-Kashani - M. Sc. Environmental engineering Trend in Environmental pollution, Faculty of Environmental Science, Tonecabon branch, Islamic Azad University, Mazandaran, Iran
Shohreh Tavakkoli - M. Sc. Environmental engineering Trend in Environmental pollution, Faculty of Environmental Science, Tonecabon branch, Islamic Azad University, Mazandaran, Iran
Saeid Malek-Mohammadi - M. Sc. Environmental engineering Trend in Environmental pollution, Faculty of Environmental Science, Hamedan branch, Islamic Azad University, Hamedan, Iran

Manufacturing of hard biodegradable petroleum based plastics harmfully affect the environment. Polyhydroxyalkanoates (PHAs) naturally produced as carbon storage polymer by various Monera kingdom microorganisms, resemble synthetic polymers in many chemical and physical properties. Renewable and biodegradable features made attracted much attention to these polyester bond polymers. PHAs extraction studied in many microorganisms made it naturally or engineered, where Poly 3- hydroxybutyric acid (PHB) is the most common. Main enzymes involved in PHB synthesis by Ralstonia eutropha encode by phbCAB gen cluster. Production of polyester particles is induced by excess quantity of carbon sources and nitrogen or some other factors starvation. PHAs production costs are still a drawback to wide usage, the future trend should focus on more efficient and economical processes developing for PHA production.

Bioplastics, Polyhydroxyalkanoates (PHAs), Microorganisms, Pathways