title: Co-occurrence of nitrite-dependent anaerobic ammonium and methane oxidation processes in subtropical acidic forest soils.
abstract: Anaerobic ammonium oxidation (anammox) and nitrite-dependent anaerobic methane oxidation (n-damo) are two new processes of recent discoveries linking the microbial nitrogen and carbon cycles. In this study, 16S ribosomal RNA (rRNA) gene of anammox bacteria and pmoA gene of n-damo bacteria were used to investigate their distribution and diversity in natural acidic and re-vegetated forest soils. The 16S rRNA gene sequences retrieved featured at least three species in two genera known anammox bacteria, namely Candidatus Brocadia anammoxidans, Candidatus Brocadia fulgida, and Candidatus Kuenenia stuttgartiensis while the pmoA gene amplified was affiliated with two species of known n-damo bacteria Candidatus Methylomirabilis oxyfera and a newly established Candidatus Methylomirabilis sp. According to the results, the diversity of anammox bacteria in natural forests was lower than in re-vegetated forests, but no significant difference was observed in n-damo community between them. Quantitative real-time PCR showed that both anammox and n-damo bacteria were more abundant in the lower layer (10-20 cm) than the surface layer (0-5 cm). The abundance of anammox bacteria varied from 2.21 × 10(5) to 3.90 × 10(6) gene copies per gram dry soil, and n-damo bacteria quantities were between 1.69 × 10(5) and 5.07 × 10(6) gene copies per gram dry soil in the two different layers. Both anammox and n-damo bacteria are reported for the first time to co-occur in acidic forest soil in this study, providing a more comprehensive information on more defined microbial processes contributing to C and N cycles in the ecosystems.
authors.affiliation: Laboratory of Environmental Microbiology and Toxicology, School of Biological Sciences, Faculty of Science, The University of Hong Kong, Pokfulam Road, Hong Kong, SAR, People's Republic of China.
authors.forename: Han
authors.initials: H
authors.lastname: Meng
authors.affiliation: Guangdong Provincial Key Laboratory of Bio-control for the Forest Disease and Pest, Guangdong Academy of Forestry, No. 233, Guangshan 1st Road, Guangzhou, People's Republic of China.|Laboratory of Microbial Ecology and Toxicology, Guangdong Academy of Forestry, No. 233, Guangshan 1st Road, Guangzhou, People's Republic of China.
authors.forename: Yong-Feng
authors.initials: YF
authors.lastname: Wang
authors.affiliation: Laboratory of Environmental Microbiology and Toxicology, School of Biological Sciences, Faculty of Science, The University of Hong Kong, Pokfulam Road, Hong Kong, SAR, People's Republic of China.
authors.forename: Ho-Wang
authors.initials: HW
authors.lastname: Chan
authors.affiliation: Laboratory of Environmental Microbiology and Toxicology, School of Biological Sciences, Faculty of Science, The University of Hong Kong, Pokfulam Road, Hong Kong, SAR, People's Republic of China.
authors.forename: Ruo-Nan
authors.initials: RN
authors.lastname: Wu
authors.affiliation: Laboratory of Environmental Microbiology and Toxicology, School of Biological Sciences, Faculty of Science, The University of Hong Kong, Pokfulam Road, Hong Kong, SAR, People's Republic of China. jdgu@hku.hk.
authors.forename: Ji-Dong
authors.initials: JD
authors.lastname: Gu
mesh_terms: D064751:Ammonium Compounds / Q000378:metabolism*; D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D065928:Forests; D008697:Methane / Q000378:metabolism*; D009573:Nitrites / Q000378:metabolism*; D010084:Oxidation-Reduction; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012988:Soil Microbiology
chemical_list: D064751:Ammonium Compounds; D009573:Nitrites; D012336:RNA, Ribosomal, 16S; D008697:Methane
keywords: Anammox bacteria; Carbon cycle; Forest soil; N-damo bacteria; Nitrogen cycle; pmoA gene