title: Demethylation of arsenic limits its volatilization in fungi.
abstract: Arsenic (As) biomethylation is increasingly being regarded as a promising method to volatize As from the environment; however, the As volatilization efficiency of most microorganisms is low. Here, the speciation transformation of dimethylarsinic acid (DMA) as an important methylation intermediate in the cells of Fusarium oxysporum CZ-8F1, Penicillium janthinellum SM-12F4, and Trichoderma asperellum SM-12F1 were investigated. These fungal strains have been certified to volatilize As from As-loaded environment. In situ X-ray absorption near edge structure (XANES) indicated that demethylation of DMA with methylarsonic acid (MMA), arsenate [As(V)], and arsenite [As(III)] as intermediates or products occurred in fungal cells after exposure to DMA for 15 days. 36.7-55.7% of the original DMA could lose one or two methyl groups and be changed into MMA or inorganic As. Chromatographic separation of the cell lysates also supported these findings. Thus it comes that demethylation might be a remarkable internal factor limiting As volatilization efficiency.
authors.affiliation: Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences/Key Laboratory of Agro-Environment, Ministry of Agriculture, Beijing, PR China. Electronic address: sushiming@caas.cn.
authors.forename: Shiming
authors.initials: S
authors.lastname: Su
authors.affiliation: Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences/Key Laboratory of Agro-Environment, Ministry of Agriculture, Beijing, PR China. Electronic address: zengxibai@caas.cn.
authors.forename: Xibai
authors.initials: X
authors.lastname: Zeng
authors.affiliation: College of Resource and Environment, Hunan Agricultural University, Changsha, Hunan Province, PR China.
authors.forename: Qiufen
authors.initials: Q
authors.lastname: Feng
authors.affiliation: Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences/Key Laboratory of Agro-Environment, Ministry of Agriculture, Beijing, PR China.
authors.forename: Lingyu
authors.initials: L
authors.lastname: Bai
authors.affiliation: Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai, PR China.
authors.forename: Lili
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai, PR China.
authors.forename: Sheng
authors.initials: S
authors.lastname: Jiang
authors.affiliation: Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai, PR China.
authors.forename: Aiguo
authors.initials: A
authors.lastname: Li
authors.affiliation: Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences/Key Laboratory of Agro-Environment, Ministry of Agriculture, Beijing, PR China.
authors.forename: Ran
authors.initials: R
authors.lastname: Duan
authors.affiliation: Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences/Key Laboratory of Agro-Environment, Ministry of Agriculture, Beijing, PR China.
authors.forename: Xiurong
authors.initials: X
authors.lastname: Wang
authors.affiliation: Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences/Key Laboratory of Agro-Environment, Ministry of Agriculture, Beijing, PR China.
authors.forename: Cuixia
authors.initials: C
authors.lastname: Wu
authors.affiliation: Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences/Key Laboratory of Agro-Environment, Ministry of Agriculture, Beijing, PR China.
authors.forename: Yanan
authors.initials: Y
authors.lastname: Wang
mesh_terms: D001151:Arsenic / Q000737:chemistry* / Q000378:metabolism; D005670:Fusarium / Q000378:metabolism*; D008745:Methylation; D010407:Penicillium / Q000378:metabolism*; D014242:Trichoderma / Q000378:metabolism*; D014835:Volatilization
chemical_list: D001151:Arsenic
keywords: Arsenic; DMA; Demethylation; Fungi; XAS