Comparison of arsenate reduction and release by three As(V)-reducing bacteria isolated from arsenic-contaminated soil of Inner Mongolia, China

Abstract

h i g h l i g h t sWe isolated three anaerobic As(Ⅴ)-reducing bacterium from soil with high ratio of As(Ⅲ). Strains JQ, DJ-3 and DJ-4 could transform very high concentration of As(Ⅴ) to As(Ⅲ). All the three strains could release goethite-adsorbed As(Ⅴ) into solution. We compared the three strains with other previously isolated strains. The existence of the strains will cause the mobilization and transformation of As in soil. Handling Editor: X. Cao Keywords:As(Ⅴ)-reducing bacteria Arsenate reduction As release Goethite a b s t r a c t Arsenic (As) contamination has become a worldwide environmental problem: arsenite (As(Ⅲ)) especially has posed a major threat to human health. Here, we report the first three isolates of anaerobic As(Ⅴ)-reducing bacterial strains (strains JQ, DJ-3 and DJ-4) from a soil sample containing 48.7% of total As in the form of As(III) collected in Chifeng, Inner Mongolia, China. Strains JQ, DJ-3 and DJ-4 were phylogenetically closely related to Bacillus, Desulfitobacterium and Exiguobacterium, respectively. Among these strains, JQ and DJ-3 have the arsC gene, DJ-4 possesses the arrA gene. The three strains could all resist and reduce high concentrations of As(Ⅴ) under anoxic conditions. The order of resistance to As(Ⅴ) was DJ-3 > JQ > DJ-4. Strain DJ-3 not only possesses the strongest resistance to As(Ⅴ) but could also reduce 53% of the As(Ⅴ) to As(III) in the treatment of 60 mM As(Ⅴ) in 5 d. All three strains could release As from goethite; strain DJ-4 has the highest ability to promote the release of As (90.5%) from goethite. These results suggested that strains JQ, DJ-3 and DJ-4 may play an important role in the mobilization and transformation of As in soil.

Prospective role of indigenousExiguobacterium profundumPT2 in arsenic biotransformation and biosorption by planktonic cultures and biofilms

“…Some other species of this genus have already been reported to resist As (Cai et al . ; Pandey and Bhatt ). The tolerance of As 5+ against E. profundum PT2 in LB and AWWE reported in this study is one of the highest As tolerance levels by any bacterial isolate reported previously (Kaur et al .…”

Recognition of a New Cr(VI)-Reducing Strain and Study of the Potential Capacity for Reduction of Cr(VI) of the Strain

“…Then the mixture was stored at -20°C before PCR amplification. The 16S rRNA genes were amplified with 27F and 1492R [37]. Conditions of PCR amplification were as follows: 5 min at 95°C; then 30 cycles of 30 s at 95°C, 30 s at 55°C, and 90 s at 72°C; then 10 min at 72°C and a hold at 4°C.…”

Impact of Organic Matter on Microbially-Mediated Reduction and Mobilization of Arsenic and Iron in Arsenic(V)-Bearing Ferrihydrite

“…DJ-3 and Exiguobacterium sp. DJ-4, were isolated from the soil of an arsenic-contaminated mine in Inner Mongolia, China . Strains DJ-3 and DJ-4 can utilize Fe­(III) and As­(V) as electron acceptors. , Among these strains, DJ-4 is the first Exiguobacterium strain isolated from soil that is capable of reducing As­(V) …”