title: Response of soil microbial communities to roxarsone pollution along a concentration gradient.
abstract: The extensive use of roxarsone (3-nitro-4-hydroxyphenylarsonic acid) as a feed additive in the broiler poultry industry can lead to environmental arsenic contamination. This study was conducted to reveal the response of soil microbial communities to roxarsone pollution along a concentration gradient. To explore the degradation process and degradation kinetics of roxarsone concentration gradients in soil, the concentration shift of roxarsone at initial concentrations of 0, 50, 100, and 200 mg/kg, as well as that of the arsenic derivatives, was detected. The soil microbial community composition and structure accompanying roxarsone degradation were investigated by high-throughput sequencing. The results showed that roxarsone degradation was inhibited by a biological inhibitor, confirming that soil microbes were absolutely essential to its degradation. Moreover, soil microbes had considerable potential to degrade roxarsone, as a high initial concentration of roxarsone resulted in a substantially increased degradation rate. The concentrations of the degradation products HAPA (3-amino-4-hydroxyphenylarsonic acid), AS(III), and AS(V) in soils were significantly positively correlated. The soil microbial community composition and structure changed significantly across the roxarsone contamination gradient, and the addition of roxarsone decreased the microbial diversity. Some bacteria tended to be inhibited by roxarsone, while Bacillus, Paenibacillus, Arthrobacter, Lysobacter, and Alkaliphilus played important roles in roxarsone degradation. Moreover, HAPA, AS(III), and AS(V) were significantly positively correlated with Symbiobacterium, which dominated soils containing roxarsone, and their abundance increased with increasing initial roxarsone concentration. Accordingly, Symbiobacterium could serve as indicator of arsenic derivatives released by roxarsone as well as the initial roxarsone concentration. This is the first investigation of microbes closely related to roxarsone degradation.
authors.affiliation: a Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences , Shijiazhuang , China.|b Key Laboratory of Groundwater Remediation of Hebei Province and China Geological Survey , Shijiazhuang, Hebei , China.
authors.forename: Yaci
authors.initials: Y
authors.lastname: Liu
authors.affiliation: a Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences , Shijiazhuang , China.
authors.forename: Zhaoji
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: a Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences , Shijiazhuang , China.|c CSIRO Land and Water , Urrbrae , South Australia , Australia.
authors.forename: Yasong
authors.initials: Y
authors.lastname: Li
authors.affiliation: d Department of Water Environmental Planning , Chinese Academy for Environmental Planning , Beijing , China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Wen
authors.affiliation: a Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences , Shijiazhuang , China.
authors.forename: Yuhong
authors.initials: Y
authors.lastname: Fei
mesh_terms: D000818:Animals; D001673:Biodegradation, Environmental; D044822:Biodiversity; D004305:Dose-Response Relationship, Drug; D004784:Environmental Monitoring / Q000379:methods*; D007700:Kinetics; D059013:Microbial Consortia / Q000187:drug effects*; D012406:Roxarsone / Q000737:chemistry / Q000633:toxicity*; D012987:Soil / Q000737:chemistry*; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000737:chemistry / Q000633:toxicity*
chemical_list: D012987:Soil; D012989:Soil Pollutants; D012406:Roxarsone
keywords: Biotransformation; Symbiobacterium; first-order kinetic model; indicator