title: Arsenic speciation transformation and arsenite influx and efflux across the cell membrane of fungi investigated using HPLC-HG-AFS and in-situ XANES.
abstract: Microorganisms dominated speciation of arsenic (As) play an important role in the biogeochemical cycling of As. In the study, species transformation of arsenite [As(III)] and As(III) influx and efflux across the cell membranes of Trichoderma asperellum SM-12F1, Penicillium janthinellum SM-12F4, and Fusarium oxysporum CZ-8F1 cells were studied using a cellular lysis plus chromatographic separation method and further the in-situ X-ray absorption near edge structure (XANES) analysis. The results indicated that As(III) can enter into fungal cells and that a portion of the As(III) can be exuded out of cells. For both As sequestrated into fungal cytoplasm and As adsorbtion onto cell walls, As(III) was found to be the dominated form of As. XANES analysis showed that As(III) accounted for 58.4%, 59.5%, and 73.0% of the total As in the cells of T. asperellum SM-12F1, P. janthinellum SM-12F4, and F. oxysporum CZ-8F1, respectively. Among these fungal strains, however, there were obvious differences in the relative proportions of arsenate [As(V)], monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA). For T. asperellum SM-12F1, the proportion (%) of MMA was 31.1%, and no As(V) or DMA was detected. For F. oxysporum CZ-8F1, the proportions of As(V) and MMA were 15.8% and 8.8%, respectively, but no DMA was observed. As(V), MMA, and DMA accounted for 4.2%, 29.5%, and 8.1%, respectively, of the P. janthinellum SM-12F4 cells. Some of the intracellular As(III) can be oxidated and methylated by these fungal strains and yield As(V), MMA, and DMA as products.
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: 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: 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: Xiurong
authors.initials: X
authors.lastname: Wang
authors.affiliation: College of Resource and Environment, Hunan Agricultural University, Changsha, Hunan Province, PR China.
authors.forename: Yangzhu
authors.initials: Y
authors.lastname: Zhang
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: Lianfang
authors.initials: L
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: Yanan
authors.initials: Y
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: Lingyu
authors.initials: L
authors.lastname: Bai
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
mesh_terms: D001149:Arsenates / Q000378:metabolism; D001151:Arsenic / Q000737:chemistry* / Q000378:metabolism; D001152:Arsenicals / Q000378:metabolism; D018053:Arsenites / Q000378:metabolism*; D001692:Biological Transport / Q000502:physiology; D002101:Cacodylic Acid / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D005670:Fusarium / Q000378:metabolism*; D010084:Oxidation-Reduction; D010407:Penicillium / Q000378:metabolism*; D014242:Trichoderma / Q000378:metabolism*; D056928:X-Ray Absorption Spectroscopy
chemical_list: D001149:Arsenates; D001152:Arsenicals; D018053:Arsenites; D002101:Cacodylic Acid; C020300:monomethylarsonic acid; C015001:arsenite; D001151:Arsenic; C025657:arsenic acid
keywords: Arsenite; De-toxicity; Fungi; Speciation transformation; XANES