title: Arsenic resistance and removal by marine and non-marine bacteria.
abstract: Arsenic resistance and removal was evaluated in nine bacterial strains of marine and non-marine origins. Of the strains tested, Marinomonas communis exhibited the second-highest arsenic resistance with median effective concentration (EC(50)) value of 510 mg As l(-1), and was capable of removing arsenic from culture medium amended with arsenate. Arsenic accumulation in cells amounted to 2290 microg As g(-1) (dry weight) when incubated on medium containing 5 mg As l(-1) of arsenate. More than half of the arsenic removed was related to metabolic activity: 45% of the arsenic was incorporated into the cytosol fraction and 10% was found in the lipid-bound fraction of the membrane, with the remaining arsenic considered to be adsorbed onto the cell surface. Potential arsenic resistance and removal were also examined in six marine and non-marine environmental water samples. Of the total bacterial colony counts, 28-100% of bacteria showed arsenic resistance. Some of the bacterial consortia, especially those from seawater enriched with arsenate, exhibited higher accumulated levels of arsenic than M. communis under the same condition. These results showed that arsenic resistant and/or accumulating bacteria are widespread in the aquatic environment, and that arsenic-accumulating bacteria such as M. communis are potential candidates for bioremediation of arsenic contaminated water.
authors.affiliation: Institute for Geo-Resources and Environment, National Institute of Advanced Industrial Science and Technology (AIST), 16-1 Onogawa, Tsukuba, Ibaraki 305-8569, Japan. takeuchi-mio@aist.go.jp
authors.forename: Mio
authors.initials: M
authors.lastname: Takeuchi
authors.forename: Hodaka
authors.initials: H
authors.lastname: Kawahata
authors.forename: Lallan Prasad
authors.initials: LP
authors.lastname: Gupta
authors.forename: Noriko
authors.initials: N
authors.lastname: Kita
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Morishita
authors.forename: Yoshiro
authors.initials: Y
authors.lastname: Ono
authors.forename: Takeshi
authors.initials: T
authors.lastname: Komai
mesh_terms: D001149:Arsenates / Q000378:metabolism* / Q000494:pharmacology; D001673:Biodegradation, Environmental; D001711:Biotransformation / Q000502:physiology; D024881:Drug Resistance, Bacterial / Q000502:physiology*; D053544:Marinomonas / Q000378:metabolism*; D012623:Seawater / Q000382:microbiology; D014871:Water Microbiology; D014874:Water Pollutants, Chemical / Q000378:metabolism* / Q000494:pharmacology
chemical_list: D001149:Arsenates; D014874:Water Pollutants, Chemical; C025657:arsenic acid