(Project concluded on November 30, 2020)

Polyhydroxybutyrate (PHB) is an attractive substitute for petroleum based plastic due to its similar properties, biocompatibility, and biodegradability. Among cheap substrates which are used for reducing total cost of PHB production, some C1 carbon sources, e.g., methane, methanol, and CO2 have received a great deal of attention due to their serious role in environmental problems. Recently, many authors have been reported the isolation and cultivation of methanotrophic bacteria able to produce PHB from methane and the feasibility of growing methanotrophic biomass in a fed batch reactor at ambient temperature and non-sterile conditions. Based on these findings, CH4 could be utilized as the carbon source of mixed culture to grow and produce PHB in a brief non-sterile process. These results will be very important to scale-up an industrial process, where sterility could represent a problem. In this context, biotechnological process could be used to transform CH4 into value-added products. The challenge in this research is the establishment of optimal conditions for a high yield of product by methanotrophic bacteria in non-sterile conditions.