title: Arsenic mineral dissolution and possible mobilization in mineral-microbe-groundwater environment.
abstract: Arsenic (As) is widely distributed in the nature as ores or minerals. It has been attracted much attention for the global public health issue, especially for groundwater As contamination. The aim of this study was to elucidate the characteristics of microbes in groundwater where As-minerals were dissolved. An ex situ experiment was conducted with 7 standard As-minerals in bacteria-free groundwater and stored in experimental vessels for 1 year without supplementary nutrients. The pH (6.7-8.4) and EhS.H.E. (24-548 mV) changed between initial (0 day) and final stages (365 days) of experiment. The dissolution of As was detected higher from arsenolite (4240 ± 8.69 mg/L) and native arsenic (4538 ± 9.02 mg/L), whereas moderately dissolved from orpiment (653 ± 3.56 mg/L) and realgar (319 ± 2.56 mg/L) in compare to arsenopyrite (85 ± 1.25mg/L) and tennantite (3 ± 0.06 mg/L). Optical microscopic, scanning electron microscopic observations and flurometric enumeration revealed the abundance of As-resistant bacillus, coccus and filamentous types of microorganisms on the surface of most of As-mineral. 4'-6-Diamidino-2-phenylindole (DAPI)-stained epifluorescence micrograph confirmed the presence of DNA and carboxyfluorescein diacetate (CFDA) staining method revealed the enzymatically active bacteria on the surface of As-minerals such as in realgar (As4S4). Therefore, the microbes enable to survive and mobilize the As in groundwater by dissolution/bioweathering of As-minerals.
authors.affiliation: Department of Human Ecology, School of International Health, Graduate School of Medicine, The University of Tokyo,7-3-1, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan; ITO Public Nuisance Research Institute, 1-26-8, Omori Kita, Otaku, Tokyo 142-0016, Japan. Electronic address: uttambangla@yahoo.com.
authors.forename: A B M R
authors.initials: AB
authors.lastname: Islam
authors.forename: Jyoti Prakash
authors.initials: JP
authors.lastname: Maity
authors.forename: Jochen
authors.initials: J
authors.lastname: Bundschuh
authors.forename: Chien-Yen
authors.initials: CY
authors.lastname: Chen
authors.forename: Bejon Kumar
authors.initials: BK
authors.lastname: Bhowmik
authors.forename: Kazue
authors.initials: K
authors.lastname: Tazaki
mesh_terms: D001151:Arsenic / Q000737:chemistry*; D001152:Arsenicals / Q000737:chemistry; D001419:Bacteria / Q000378:metabolism*; D004247:DNA / Q000737:chemistry; D004784:Environmental Monitoring; D004785:Environmental Pollutants; D005470:Fluorometry; D060587:Groundwater / Q000382:microbiology*; D006863:Hydrogen-Ion Concentration; D008855:Microscopy, Electron, Scanning; D008856:Microscopy, Fluorescence; D010100:Oxygen / Q000737:chemistry; D012995:Solubility; D013440:Sulfides / Q000737:chemistry; D013696:Temperature; D014871:Water Microbiology; D014874:Water Pollutants, Chemical / Q000737:chemistry; D014961:X-Ray Diffraction
chemical_list: D001152:Arsenicals; D004785:Environmental Pollutants; D013440:Sulfides; D014874:Water Pollutants, Chemical; C045816:arsenic trisulfide; C058317:arsenic disulfide; D004247:DNA; D001151:Arsenic; D010100:Oxygen