Recent Advances in polyhydroxyalkanoates production by mixed cultures

Polyhydroxyalkanoates(PHA) are biodegradable plastics synthesized by microorganism,which can be used as a substitute of chemical plastics. Synthesizing PHA by pure cultures is expensive due to the use of glucose and other high-quality substrates and the requirement of sterilization for the process,seriously restricting the widespread use of PHA; while synthetizing PHA by mixed cultures can use waste as substrate thus significantly reducing cost. The purpose of this paper is to describe the research advances in PHA production by mixed cultures,such as its history,synthesis mechanism,production process,and extraction method. The development of PHA production by mixed cultures is reviewed; two main synthesis mechanisms are described; metabolic pathways of different substrates to synthesize PHA are introduced; a three-stage synthesis process and product extraction are addressed; and recent research trends are summarized. Future research in this area should be focused on increasing concentration of mixed cultures and capacity of using real waste.