title: Long-term field fertilization alters the diversity of autotrophic bacteria based on the ribulose-1,5-biphosphate carboxylase/oxygenase (RubisCO) large-subunit genes in paddy soil.
abstract: Carbon dioxide (CO(2)) assimilation by autotrophic bacteria is an important process in the soil carbon cycle with major environmental implications. The long-term impact of fertilizer on CO(2) assimilation in the bacterial community of paddy soils remains poorly understood. To narrow this knowledge gap, the composition and abundance of CO(2)-assimilating bacteria were investigated using terminal restriction fragment length polymorphism and quantitative PCR of the cbbL gene [that encodes ribulose-1,5-biphosphate carboxylase/oxygenase (RubisCO)] in paddy soils. Soils from three stations in subtropical China were used. Each station is part of a long-term fertilization experiment with three treatments: no fertilizer (CK), chemical fertilizers (NPK), and NPK combined with rice straw (NPKM). At all of the stations, the cbbL-containing bacterial communities were dominated by facultative autotrophic bacteria such as Rhodopseudomonas palustris, Bradyrhizobium japonicum, and Ralstonia eutropha. The community composition in the fertilized soil (NPK and NPKM) was distinct from that in unfertilized soil (CK). The bacterial cbbL abundance (3-8 × 10(8) copies g soil(-1)) and RubisCO activity (0.40-1.76 nmol CO(2) g soil(-1) min(-1)) in paddy soils were significantly positively correlated, and both increased with the addition of fertilizer. Among the measured soil parameters, soil organic carbon and pH were the most significant factors influencing the community composition, abundance, and activity of the cbbL-containing bacteria. These results suggest that long-term fertilization has a strong impact on the activity and community of cbbL-containing bacterial populations in paddy soils, especially when straw is combined with chemical fertilizers.
authors.affiliation: Key Laboratory of Agro-ecological Processes in Subtropical Regions, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, Hunan, China.
authors.forename: Hongzhao
authors.initials: H
authors.lastname: Yuan
authors.forename: Tida
authors.initials: T
authors.lastname: Ge
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Wu
authors.forename: Shoulong
authors.initials: S
authors.lastname: Liu
authors.forename: Chengli
authors.initials: C
authors.lastname: Tong
authors.forename: Hongling
authors.initials: H
authors.lastname: Qin
authors.forename: Minna
authors.initials: M
authors.lastname: Wu
authors.forename: Wenxue
authors.initials: W
authors.lastname: Wei
authors.forename: Jinshui
authors.initials: J
authors.lastname: Wu
mesh_terms: D001419:Bacteria / Q000145:classification / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D003001:Cloning, Molecular; D005308:Fertilizers; D005798:Genes, Bacterial; D006863:Hydrogen-Ion Concentration; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D012273:Ribulose-Bisphosphate Carboxylase / Q000378:metabolism*; D012988:Soil Microbiology
chemical_list: D005308:Fertilizers; D012273:Ribulose-Bisphosphate Carboxylase