A flexible microbial co-culture platform for simultaneous utilization of methane and carbon dioxide from gas feedstocks

Abstract A new co-cultivation technology is presented that converts greenhouse gasses, CH 4 and CO 2 , into microbial biomass. The methanotrophic bacterium, Methylomicrobium alcaliphilum 20z, was coupled to a cyanobacterium, Synechococcus PCC 7002 via oxygenic photosynthesis. The system exhibited robust growth on diverse gas mixtures ranging from biogas to those representative of a natural gas feedstock. A continuous processes was developed on a synthetic natural gas feed that achieved steady-state by imposing coupled light and O 2 limitations on the cyanobacterium and methanotroph, respectively. Continuous co-cultivation resulted in an O 2 depleted reactor and does not require CH 4 /O 2 mixtures to be fed into the system, thereby enhancing process safety considerations over traditional methanotroph mono-culture platforms. This co-culture technology is scalable with respect to its ability to utilize different gas streams and its biological components constructed from model bacteria that can be metabolically customized to produce a range of biofuels and bioproducts.