title: Response of mixed methanotrophic consortia to different methane to oxygen ratios.
abstract: Methane (CH4) and oxygen (air) concentrations affect the CH4oxidation capacity (MOC) and mixed methanotrophic community structures in compost (fresh) and landfill (age old) top cover soils. A change in the mixed methanotrophic community structure in response has implications for landfill CH4bio-filter remediation and possible bio-product outcomes (i.e., fatty acid methyl esters (FAME) content and profiles and polyhydroxybutyrate (PHB) contents). Therefore the study aimed to evaluate the effect of variable CH4to oxygen ratios (10-50% CH4in air) on mixed methanotrophic community structures enriched from landfill top cover (LB) and compost soils (CB) and to quantify flow on impacts on MOC, total FAME contents and profiles, and PHB accumulation. A stable consortium developed achieving average MOCs of 3.0±0.12, 4.1±0.26, 6.9±0.7, 7.6±1.3 and 9.2±1.2mgCH4g-1DWbiomassh-1in LB and 2.9±0.04, 5.05±0.32, 6.7±0.31, 7.9±0.61 and 8.6±0.48mgCH4g-1DWbiomassh-1in CB for a 20day cultivation period at 10, 20, 30, 40 and 50% CH4, respectively. CB at 10% CH4had a maximal FAME content of 40.5±0.8mgFAMEg-1DWbiomass, while maximal PHB contents (25mgg-1DWbiomass) was observed at 40% CH4in LB. Despite variable CH4/O2ratios, the mixed methanotrophic community structures in both LB and CB were relatively stable, dominated by Methylosarcina sp., and Chryseobacterium, suggesting that a resilient consortium had formed which can now be tested in bio-filter operations for CH4mitigations in landfills.
authors.affiliation: College of Science and Engineering, James Cook University, Townsville 4811, Queensland, Australia; Centre for Sustainable Tropical Fisheries and Aquaculture, James Cook University, Townsville 4811, Queensland, Australia.
authors.forename: K
authors.initials: K
authors.lastname: Chidambarampadmavathy
authors.affiliation: College of Science and Engineering, James Cook University, Townsville 4811, Queensland, Australia; Comparative Genomics Centre, James Cook University, Townsville 4811, Queensland, Australia; Centre for Sustainable Tropical Fisheries and Aquaculture, James Cook University, Townsville 4811, Queensland, Australia; Sino-Forest Applied Research Centre for Pearl River Delta Environment (ARCPE), Department of Biology, Hong Kong Baptist University, Kowloon Tong, Hong Kong Special Administrative Region.
authors.forename: O P
authors.initials: OP
authors.lastname: Karthikeyan
authors.affiliation: College of Science and Engineering, James Cook University, Townsville 4811, Queensland, Australia; Comparative Genomics Centre, James Cook University, Townsville 4811, Queensland, Australia; Centre for Sustainable Tropical Fisheries and Aquaculture, James Cook University, Townsville 4811, Queensland, Australia.
authors.forename: R
authors.initials: R
authors.lastname: Huerlimann
authors.affiliation: College of Science and Engineering, James Cook University, Townsville 4811, Queensland, Australia; Comparative Genomics Centre, James Cook University, Townsville 4811, Queensland, Australia; Centre for Sustainable Tropical Fisheries and Aquaculture, James Cook University, Townsville 4811, Queensland, Australia; Center for Human Genetics, Genomics Core, KU Leuven, Herestraat 49, 3000 Leuven, Belgium.
authors.forename: G E
authors.initials: GE
authors.lastname: Maes
authors.affiliation: College of Science and Engineering, James Cook University, Townsville 4811, Queensland, Australia; Comparative Genomics Centre, James Cook University, Townsville 4811, Queensland, Australia; Centre for Sustainable Tropical Fisheries and Aquaculture, James Cook University, Townsville 4811, Queensland, Australia; Centre for Bio-discovery and Molecular Development of Therapeutics, James Cook University, Townsville 4811, Queensland, Australia. Electronic address: kirsten.heimann@jcu.edu.au.
authors.forename: K
authors.initials: K
authors.lastname: Heimann
mesh_terms: D001315:Australia; D045247:Chryseobacterium / Q000235:genetics / Q000378:metabolism; D005227:Fatty Acids / Q000737:chemistry / Q000378:metabolism; D008697:Methane / Q000378:metabolism*; D008772:Methylococcaceae / Q000235:genetics / Q000378:metabolism; D059013:Microbial Consortia / Q000235:genetics / Q000502:physiology*; D010084:Oxidation-Reduction; D010100:Oxygen / Q000378:metabolism*; D011091:Polyesters / Q000378:metabolism; D000091402:Prohibitins; D012336:RNA, Ribosomal, 16S; D012988:Soil Microbiology; D064091:Waste Disposal Facilities
chemical_list: D005227:Fatty Acids; C000717328:PHB protein, human; D011091:Polyesters; D000091402:Prohibitins; D012336:RNA, Ribosomal, 16S; D008697:Methane; D010100:Oxygen
keywords: Biopolymer; Chryseobacterium; Compost soil; Landfill cover soil; Methane; Methylosarcina