Manganese(Ⅱ)-oxidizing bacteria in the aquatic environment have been comprehensively investigated.However, little information is available about the distribution and biogeochemical significance of these bacteria in terrestrial soil environments.In this study, stratified soils were examined to investigate the community structure and diversity of Mn(Ⅱ)-oxidizing bacteria as well as the properties of the manganese (Mn) oxide aggregates that these bacteria formed.Phylogenetically diverse bacteria with Mn(Ⅱ)-oxidizing activities were isolated from all substrata.The relatively dominant high Mn(Ⅱ)-oxidizing isolates were identified as the species of phyla Actinobacteria, Firmicutes, and Proteobacteria.The diversity of soil bacterial community was significantly increased after the combined enrichment of culture medium by Mn(Ⅱ) and carbon-rich complex.The enriched bacteria represented by predominant denaturing gradient gel electrophoresis bands were apparently tolerant to Mn(Ⅱ) at a certain level and belonged to the similar phylogenetic classifications with those of culturable Mn(Ⅱ)-oxidizing bacteria.Under prolonged Mn(Ⅱ) and carbon-rich medium enrichment, those isolates with high Mn(Ⅱ)-oxidizing activity were closely packed with their Mn oxides and formed regular microspherical aggregates.