Nitrate dependent Fe-oxidizing bacterial diversity in subtropical soils of China

Nitrate dependent Fe-oxidizing bacteria (NFeOB) are important to study soil C and N cycle. Although several studies have isolated and identified NFeOB communities in different environments, their diversity in paddy soils and forest soils is still not well studied. Four different soils (rice-fallow rotation and forest soil, from Qianjiang, referred as QR and QF soil, respectively, and rice-fallow rotation and forest soil, from Xianning, referred as XR and XF soil, respectively) were used to study NFeOB diversity. The anaerobic enrichment incubations were conducted three times. The dominant groups of four soils among NFeOB were Proteobacteria, Firmicutes, Actinobacteria and Bacteroidetes. At the genus level, the compositions of the NFeOB communities in four soils were Bacillus, Magnetospirillum, Clostridium, Massilia, Paucimonas, Cellulomonas and Kluyvera. The diversity of NFeOB communities was highly influenced by land use and soil properties, such as pH, parent material, SOM, CEC and Fe. The results demonstrated that NFeOB are key mediators in C and N cycling under anaerobic environments.