Characterization of Microbial Communities, Identification of Cr(VI) Reducing Bacteria in Constructed Wetland and Cr(VI) Removal Ability of Bacillus cereus

Abstract

In this study, the contribution of substrates microorganisms in three different constructed wetlands (CWs) to Cr(VI) purification was discussed. In addition, the microbial communities in the substrate of different CWs were characterized, and rhizosphere Cr(VI) reducing bacteria was also identified. The results showed that microorganisms could improved Cr(VI) removal to 76.5%, and result in that more Cr(VI) was reduced to Cr(III). The dominant strains in the substrates of different CWs were Sphingomonas sp., Cystobacter sp., Acidobacteria bacterium, Sporotrichum and Pellicularia species. The Cr(VI) reducing bacteria from Leersia hexandra Swartz rhizosphere was identified as Bacillus cereus. Furthermore, under suitable conditions, the removal rate of Cr(VI) by Bacillus cereus was close to 100%.