title: Diversity and activity of methanotrophs in landfill cover soils with and without landfill gas recovery systems.
abstract: Aerobic CH4 oxidation plays an important role in mitigating CH4 release from landfills to the atmosphere. Therefore, in this study, oxidation activity and community of methanotrophs were investigated in a subtropical landfill. Among the three sites investigated, the highest CH4 concentration was detected in the landfill cover soil of the site (A) without a landfill gas (LFG) recovery system, although the refuse in the site had been deposited for a longer time (∼14-15 years) compared to the other two sites (∼6-11 years) where a LFG recovery system was applied. In April and September, the higher CH4 flux was detected in site A with 72.4 and 51.7gm(-2)d(-1), respectively, compared to the other sites. The abundance of methanotrophs assessed by quantification of pmoA varied with location and season. A linear relationship was observed between the abundance of methanotrophs and CH4 concentrations in the landfill cover soils (R=0.827, P<0.001). The key factors influencing the methanotrophic diversity in the landfill cover soils were pH, the water content and the CH4 concentration in the soil, of which pH was the most important factor. Type I methanotrophs, including Methylococcus, Methylosarcina, Methylomicrobium and Methylobacter, and type II methanotrophs (Methylocystis) were all detected in the landfill cover soils, with Methylocystis and Methylosarcina being the dominant genera. Methylocystis was abundant in the slightly acidic landfill cover soil, especially in September, and represented more than 89% of the total terminal-restriction fragment abundance. These findings indicated that the LFG recovery system, as well as physical and chemical parameters, affected the diversity and activity of methanotrophs in landfill cover soils.
authors: Department of Environmental Engineering, Zhejiang University, Hangzhou 310058, China.
authors: Yao
authors: Y
authors: Su
authors: Department of Environmental Engineering, Zhejiang University, Hangzhou 310058, China.
authors: Xuan
authors: X
authors: Zhang
authors: Department of Environmental Engineering, Zhejiang University, Hangzhou 310058, China.
authors: Fang-Fang
authors: FF
authors: Xia
authors: Department of Environmental Engineering, Zhejiang University, Hangzhou 310058, China.
authors: Qi-Qi
authors: QQ
authors: Zhang
authors: Department of Environmental Engineering, Zhejiang University, Hangzhou 310058, China.
authors: Jiao-Yan
authors: JY
authors: Kong
authors: Department of Environmental Engineering, Zhejiang University, Hangzhou 310058, China.
authors: Jing
authors: J
authors: Wang
authors: Department of Environmental Engineering, Zhejiang University, Hangzhou 310058, China. Electronic address: heruo@zju.edu.cn.
authors: Ruo
authors: R
authors: He
mesh_terms: D000332:Aerobiosis; D044822:Biodiversity; D005740:Gases / Q000378:metabolism; D008697:Methane / Q000378:metabolism*; D008772:Methylococcaceae / Q000145:classification / Q000302:isolation & purification* / Q000378:metabolism*; D042083:Methylocystaceae / Q000145:classification / Q000302:isolation & purification* / Q000378:metabolism*; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D012621:Seasons; D017422:Sequence Analysis, DNA; D012988:Soil Microbiology; D064091:Waste Disposal Facilities
chemical_list: D005740:Gases; D008697:Methane
keywords: CH(4) oxidation activity; Landfill cover soil; Methanotrophs; pmoA