A Novel Mn- and Fe-Oxides-Reducing Bacterium with High Activity to Drive Mobilization and Release of Arsenic from Soils

Since Mn, Fe and As contaminants often coexist in the environment, we hypothesize that presence of multifunctional bacteria is capable reducing Mn oxides promoting mobilization release arsenic. However, such have not been reported yet; moreover, impact with ability to simultaneously reduce on formation high-arsenic groundwater remains unclear. This study aims address this question. Here, found microbial community soils was able efficiently into Mn(II). An analysis structures soil shows it contained Proteobacteria (41.1%), Acidobacteria (10.9%), Actinobacteria (9.5%) other less abundant bacteria. Based observation, successfully isolated a novel bacterium Cellulomonas sp. CM1, which possesses both Mn- Fe-oxide-reducing activities. Under anaerobic conditions, strain CM1 can oxides, resulting production 13 mg/L Mn(II) within span 10 days. Simultaneously, leading generation 9 Fe(II) days when yeast extract used as an electron donor. During these reduction reactions, cells were grown density OD600 0.16 0.09, respectively, suggesting Mn(IV) more beneficial for bacterial growth than Fe(III). Arsenic assays indicate after 108 anoxic incubation, approximately 126.2, 103.2 81.5 μg/L As(V) mobilized released from three samples, plays significant roles driving arsenic soils. These findings shed new light processes lead arsenic-contaminated groundwater.