title: Community structure and soil pH determine chemoautotrophic carbon dioxide fixation in drained paddy soils.
abstract: Previous studies suggested that microbial photosynthesis plays a potential role in paddy fields, but little is known about chemoautotrophic carbon fixers in drained paddy soils. We conducted a microcosm study using soil samples from five paddy fields to determine the environmental factors and quantify key functional microbial taxa involved in chemoautotrophic carbon fixation. We used stable isotope probing in combination with phospholipid fatty acid (PLFA) and molecular approaches. The amount of microbial (13)CO2 fixation was determined by quantification of (13)C-enriched fatty acid methyl esters and ranged from 21.28 to 72.48 ng of (13)C (g of dry soil)(-1), and the corresponding ratio (labeled PLFA-C:total PLFA-C) ranged from 0.06 to 0.49%. The amount of incorporationof (13)CO2 into PLFAs significantly increased with soil pH except at pH 7.8. PLFA and high-throughput sequencing results indicated a dominant role of Gram-negative bacteria or proteobacteria in (13)CO2 fixation. Correlation analysis indicated a significant association between microbial community structure and carbon fixation. We provide direct evidence of chemoautotrophic C fixation in soils with statistical evidence of microbial community structure regulation of inorganic carbon fixation in the paddy soil ecosystem.
authors.affiliation: †Institute of Urban Environment, Chinese Academy of Sciences, No. 1799 Jimei Road, Xiamen 361021, China.|‡Ningbo Urban Environment Observation and Research Station-NUEORS, Chinese Academy of Sciences, No. 88 Zhong Ke Road, Ningbo 315830, China.
authors.forename: Xi-En
authors.initials: XE
authors.lastname: Long
authors.affiliation: †Institute of Urban Environment, Chinese Academy of Sciences, No. 1799 Jimei Road, Xiamen 361021, China.|‡Ningbo Urban Environment Observation and Research Station-NUEORS, Chinese Academy of Sciences, No. 88 Zhong Ke Road, Ningbo 315830, China.
authors.forename: Huaiying
authors.initials: H
authors.lastname: Yao
authors.affiliation: †Institute of Urban Environment, Chinese Academy of Sciences, No. 1799 Jimei Road, Xiamen 361021, China.|‡Ningbo Urban Environment Observation and Research Station-NUEORS, Chinese Academy of Sciences, No. 88 Zhong Ke Road, Ningbo 315830, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Wang
authors.affiliation: †Institute of Urban Environment, Chinese Academy of Sciences, No. 1799 Jimei Road, Xiamen 361021, China.|‡Ningbo Urban Environment Observation and Research Station-NUEORS, Chinese Academy of Sciences, No. 88 Zhong Ke Road, Ningbo 315830, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Huang
authors.affiliation: §Hawkesbury Institute for the Environment, University of Western Sydney, Penrith South DC, NSW 2751, Australia.
authors.forename: Brajesh K
authors.initials: BK
authors.lastname: Singh
authors.affiliation: †Institute of Urban Environment, Chinese Academy of Sciences, No. 1799 Jimei Road, Xiamen 361021, China.
authors.forename: Yong-Guan
authors.initials: YG
authors.lastname: Zhu
mesh_terms: D001419:Bacteria / Q000145:classification / Q000378:metabolism*; D057486:Carbon Cycle / Q000235:genetics; D002245:Carbon Dioxide / Q000032:analysis*; D002247:Carbon Isotopes; D052837:Chemoautotrophic Growth; D004247:DNA / Q000378:metabolism; D058645:Denaturing Gradient Gel Electrophoresis; D005227:Fatty Acids / Q000032:analysis; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D012275:Oryza; D010743:Phospholipids / Q000032:analysis; D010802:Phylogeny; D025341:Principal Component Analysis; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012987:Soil / Q000737:chemistry*; D012988:Soil Microbiology
chemical_list: D002247:Carbon Isotopes; D005227:Fatty Acids; D010743:Phospholipids; D012336:RNA, Ribosomal, 16S; D012987:Soil; D002245:Carbon Dioxide; D004247:DNA