title: Production and Release of Selenomethionine and Related Organic Selenium Species by Microorganisms in Natural and Industrial Waters.
abstract: Laboratory algal cultures exposed to selenate were shown to produce and release selenomethionine, selenomethionine oxide, and several other organic selenium metabolites. Released discrete organic selenium species accounted for 1.6-13.1% of the selenium remaining in the media after culture death, with 1.3-6.1% of the added selenate recovered as organic metabolites. Analysis of water from an industrially impacted river collected immediately after the death of massive annual algal blooms showed that no selenomethionine or selenomethionine oxide was present. However, other discrete organic selenium species, including a cyclic oxidation product of selenomethionine, were observed, indicating the previous presence of selenomethionine. Industrial biological treatment systems designed for remediation of selenium-contaminated waters were shown to increase both the concentration of organic selenium species in the effluent, relative to influent water, and the fraction of organic selenium to up to 8.7% of the total selenium in the effluent, from less than 1.1% in the influent. Production and emission of selenomethionine, selenomethionine oxide, and other discrete organic selenium species were observed. These findings are discussed in the context of potentially increased selenium bioavailability caused by microbial activity in aquatic environments and biological treatment systems, despite overall reductions in total selenium concentration.
authors.affiliation: Environmental and Life Sciences Graduate Program, ‡Water Quality Centre, Environmental and Resource Science Program, and Department of Chemistry, Trent University , 1600 West Bank Drive, Peterborough, Ontario Canada K9J 7B8.
authors.forename: Kelly L
authors.initials: KL
authors.lastname: LeBlanc
authors.affiliation: Environmental and Life Sciences Graduate Program, ‡Water Quality Centre, Environmental and Resource Science Program, and Department of Chemistry, Trent University , 1600 West Bank Drive, Peterborough, Ontario Canada K9J 7B8.
authors.forename: Dirk
authors.initials: D
authors.lastname: Wallschläger
mesh_terms: D064586:Selenic Acid; D012643:Selenium; D018036:Selenium Compounds / Q000378:metabolism; D012645:Selenomethionine; D014867:Water
chemical_list: D018036:Selenium Compounds; D014867:Water; D012645:Selenomethionine; D012643:Selenium; D064586:Selenic Acid