title: Removal of inorganic and organic mercurials by immobilized bacteria having mer-ppk fusion plasmids.
abstract: Feasibility of biological mercury removal from wastewater was examined by using alginate-immobilized cells of Escherichia coli carrying mer-ppk fusion plasmid pMKB18. Immobilized cells engineered to express mercury-transport system, organomercurial lyase and polyphosphate efficiently removed organic and inorganic mercury from contaminated wastewater over a wide concentration range of mercurials, probably via intracellular accumulation mediated by ppk-specified polyphosphate. Bioaccumulation of mercury was selective compared to other metals such as Cd(2+), Pb(2+) and Cr(6+). The immobilized cells could be used repeatedly (at least three times) without large loss of mercury removal activity. From these results, it is concluded that the mer-ppk fusion plasmid and the immobilized cells are useful for simultaneous removal of organic and inorganic mercury from contaminated wastewater.
authors.affiliation: Faculty of Pharmaceutical Sciences, Setsunan University, 45-1 Nagaotoge-cho, Hirakata, 573-0101, Osaka, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Kiyono
authors.forename: H
authors.initials: H
authors.lastname: Omura
authors.forename: T
authors.initials: T
authors.lastname: Omura
authors.forename: S
authors.initials: S
authors.lastname: Murata
authors.forename: H
authors.initials: H
authors.lastname: Pan-Hou
mesh_terms: D019677:Artificial Gene Fusion; D018914:Cells, Immobilized; D021902:Enterobacter aerogenes / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism*; D005798:Genes, Bacterial; D017669:Mercury Compounds / Q000302:isolation & purification* / Q000378:metabolism; D008954:Models, Biological; D009941:Organomercury Compounds / Q000302:isolation & purification* / Q000378:metabolism; D017856:Phosphotransferases (Phosphate Group Acceptor) / Q000235:genetics / Q000378:metabolism; D010957:Plasmids / Q000235:genetics; D011549:Pseudomonas / Q000235:genetics; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000302:isolation & purification* / Q000378:metabolism
chemical_list: D017669:Mercury Compounds; D009941:Organomercury Compounds; D011994:Recombinant Proteins; D014874:Water Pollutants, Chemical; D017856:Phosphotransferases (Phosphate Group Acceptor); C022424:polyphosphate kinase