Polyhydroxyalkanoates production by bacterial enrichments

Polyhydroxyalkanoates (PHAs) is a natural bacterial storage compound, which can be used as carbon and electron source. Their remarkable similarities in physical properties to conventional plastics, such as polypropylene, attract great commercial interest. This thesis focuses on PHAs production by bacterial enrichments. As compared to the current pure culture biotechnology, mixed culture biotechnology is much less dependent on the well defined substrate and sterile process. These properties of mixed culture biotechnology can greatly reduce the price of the final products. The major aims of this thesis are to optimize the process to select bacterial enrichments with superior PHAs-producing capacity and analyze the microbial community compositions in these enrichments. In my PhD studies, the main findings are: (1) both the maximal bacterial PHAs content and biomass specific PHAs productivity have been significantly improved. (2) the new selective pressure to enrich bacterial species with superior PHA producing capacity has been found. (3) several novel bacterial speices have been isolated and characterized. Based on these findings, converting argo-industrial waste to valuable chemical compounds can be achieved. Currently, a demo-scale production reactor is being constructed.BiotechnologyApplied Science