INTERMITTENT APPLICATION OF REDUCED NITROGEN SOURCES FOR SELECTION OF PHB PRODUCING METHANOTROPHS

摘要

A method of selection of polyhydroxybutyrate (PHB) producing Type II methanotrophs is provided that includes enriching PHB-producing methanotrophic strains, using a bioreactor, where ammonium includes a nitrogen source, where growth of the enriched PHB cells on ammonium selects for a PHB-producing methanotrophic strains by inhibiting survival of Type I organism growth, growing the enriched PHB-producing strains, using the bioreactor, on nitrate or urea to promote rapid and more dense growth of the enriched PHB-producing strains, where production of the PHB occurs when nitrogen is exhausted, and cycling between the enriching PHB-producing methanotrophic strains and growing the enriched PHB-producing strains, using the bioreactor, where a mixed culture of the PHB-producing strains are maintained without reducing growth rates of the methanotrophic strains or PHB production rates in the bioreactor.