Microbial ferric iron reduction, with organic carbon or hydrogen as the electron donor, is one of the most important biogeochemical processes in anoxic paddy soils; however, the diversity and community structure of hy...Microbial ferric iron reduction, with organic carbon or hydrogen as the electron donor, is one of the most important biogeochemical processes in anoxic paddy soils; however, the diversity and community structure of hydrogen-dependent dissimilatory iron-reducers remain unknown. Potential H2-dependent Fe（III）-reducing bacteria in paddy soils were explored using enrichment cultures with ferrihydrite or goethite as the electron acceptor and hydrogen as the electron donor. Terminal restriction fragment length polymorphism （T-RFLP） analysis and cloning/sequencing were conducted to reveal bacterial community structure. Results showed that Geobacter and Clost^dium were the dominant bacteria in the enrichment cultures. Fe（III） oxide mineral phases showed a strong effect on the community structure; Geobaeter and Clostridium were dominant in the ferrihydrite treatment, while Glostridium spp. were dominant in the goethite treatment. These suggested that H2-dependent Fe（lII）-redueing bacteria might be widely distributed in paddy soils and that besides Geobacter, Clostmdium spp. might also be an important group of H2-dependent Fe（III）-reducing microorganisms.展开更多
基金Supported by the National Natural Science Foundation of China (No.41090282)
文摘Microbial ferric iron reduction, with organic carbon or hydrogen as the electron donor, is one of the most important biogeochemical processes in anoxic paddy soils; however, the diversity and community structure of hydrogen-dependent dissimilatory iron-reducers remain unknown. Potential H2-dependent Fe（III）-reducing bacteria in paddy soils were explored using enrichment cultures with ferrihydrite or goethite as the electron acceptor and hydrogen as the electron donor. Terminal restriction fragment length polymorphism （T-RFLP） analysis and cloning/sequencing were conducted to reveal bacterial community structure. Results showed that Geobacter and Clost^dium were the dominant bacteria in the enrichment cultures. Fe（III） oxide mineral phases showed a strong effect on the community structure; Geobaeter and Clostridium were dominant in the ferrihydrite treatment, while Glostridium spp. were dominant in the goethite treatment. These suggested that H2-dependent Fe（lII）-redueing bacteria might be widely distributed in paddy soils and that besides Geobacter, Clostmdium spp. might also be an important group of H2-dependent Fe（III）-reducing microorganisms.
