title: [Competitive Microbial Oxidation and Reduction of Arsenic].
abstract: Filters are widely applied in drinking water treatment plants. Our previous study, which explored the asenic redox in a filter of drinking water plant treating underground water, found that As3+ could be oxidized to As5+ by biogenic manganese oxides, while As5+ could be reduced to As3+ by some microbial arsenic reductases in the biofilter system. This microbial competition could influence the system stability and treatment efficiency. To explore its mechanism, this study selected a manganese-oxidizing bacterial strain (Pseudomonas sp. QJX-1) and a arsenic-reducing strain (Brevibacterium sp. LSJ-9) to investigate their competitive relationship in nutrient acquisition and arsenic redox in the presence of Mn2+, As3+ or As5+ The results revealed that the concentration and valence of Mn and As varied with different reaction time; biological manganese oxides dominated the arsenic redox by rapidly oxidizing the As3+ in the existing system and the As3+ generated by arsenic reductase into As. PCR and RT-PCR results indicated that the arsenic reductase (arsC) was inhibited by the manganese oxidase (cumA). The expression of 16S rRNA in QJX-1 was two orders of magnitude higher than that in LSJ-9, which implied QJX-1 was dominant in the bacterial growth. Our data revealed that hydraulic retention time was critical to the valence of arsenic in the effluent of filter in drinking water treatment plant.
authors.forename: Ting-ting
authors.initials: TT
authors.lastname: Yang
authors.forename: Yao-hui
authors.initials: YH
authors.lastname: Bai
authors.forename: Jin-song
authors.initials: JS
authors.lastname: Liang
authors.forename: Yang
authors.initials: Y
authors.lastname: Huo
authors.forename: Ming-xing
authors.initials: MX
authors.lastname: Wang
authors.forename: Lin-ijang
authors.initials: LI
authors.lastname: Yuan
mesh_terms: D001151:Arsenic / Q000737:chemistry*; D001673:Biodegradation, Environmental; D001951:Brevibacterium / Q000378:metabolism*; D060766:Drinking Water / Q000737:chemistry; D060587:Groundwater / Q000737:chemistry; D017895:Manganese Compounds / Q000737:chemistry*; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry*; D010088:Oxidoreductases / Q000378:metabolism; D011549:Pseudomonas / Q000378:metabolism*; D012336:RNA, Ribosomal, 16S; D018508:Water Purification / Q000379:methods*
chemical_list: D060766:Drinking Water; D017895:Manganese Compounds; D010087:Oxides; D012336:RNA, Ribosomal, 16S; C027424:manganese oxide; D010088:Oxidoreductases; D001151:Arsenic