Abstract: Polyhydroxyalkanoate（PHA）,a kind of high molecular biopolymer,is synthesized by microorganisms and accumulated in microbial cells with the limitation of essential nutrients and excessive carbon source in the medium. PHA products are promising biodegradable materials with excellent physicochemical properties and are expected to be as potential alternatives of traditional plastics for avoiding the pollution of “white plastic waste”. However,the high cost of production limits its industrialization and application in large-scale. Exploring some cheap feedstock as carbon resource of microorganisms to produce the PHA is one of the feasible approaches to reduce the cost. Waste oil as carbon-hydrogen component presents the promising potentials of utilization by microorganisms. Recently,it has become a research hotspot to synthesize biodegradable plastics by microorganisms using waste oil as raw material. This strategy can not only reduce the costs of PHA production,but also achieve the high-value utilization of waste oil. The replacement of traditional fossil fuel plastics by biodegradable plastics conforms to the sustainable development strategy in China. This paper systematically summarizes various types of PHA and its applications,the latest progress in the synthesis of PHA from waste oil by microbes,and the extraction methods of PHA from microbial cells. Finally,some insights and outlooks are provided on the development of PHA production from waste oils.

Key words: polyhydroxyalkanoate, degradable plastics, waste oil, microbial synthesis