title: Characterization of a thermophilic sulfur oxidizing enrichment culture dominated by a Sulfolobus sp. obtained from an underground hot spring for use in extreme bioleaching conditions.
abstract: A thermoacidophilic elemental sulfur and chalcopyrite oxidizing enrichment culture VS2 was obtained from hot spring run-off sediments of an underground mine. It contained only archaeal species, namely a Sulfolobus metallicus-related organism (96% similarity in partial 16S rRNA gene) and Thermoplasma acidophilum (98% similarity in partial 16S rRNA gene). The VS2 culture grew in a temperature range of 35-76 degrees C. Sulfur oxidation by VS2 was optimal at 70 degrees C, with the highest oxidation rate being 99 mg S(0 )l(-1 )day(-1). At 50 degrees C, the highest sulfur oxidation rate was 89 mg l(-1 )day(-1 )(in the presence of 5 g Cl(-) l(-1)). Sulfur oxidation was not significantly affected by 0.02-0.1 g l(-1) yeast extract or saline water (total salinity of 0.6 M) that simulated mine water at field application sites with availability of only saline water. Chloride ions at a concentration above 10 g l(-1) inhibited sulfur oxidation. Both granular and powdered forms of sulfur were bioavailable, but the oxidation rate of granular sulfur was less than 50% of the powdered form. Chalcopyrite concentrate oxidation (1% w/v) by the VS2 resulted in a 90% Cu yield in 30 days.
authors.affiliation: Institute of Environmental Engineering and Biotechnology, Tampere University of Technology, 33101 Tampere, Finland. salov@hotmail.com
authors.forename: Virpi L A
authors.initials: VL
authors.lastname: Salo-Zieman
authors.forename: Tarja
authors.initials: T
authors.lastname: Sivonen
authors.forename: Jason J
authors.initials: JJ
authors.lastname: Plumb
authors.forename: Christina M
authors.initials: CM
authors.lastname: Haddad
authors.forename: Katja
authors.initials: K
authors.lastname: Laukkanen
authors.forename: Päivi H M
authors.initials: PH
authors.lastname: Kinnunen
authors.forename: Anna H
authors.initials: AH
authors.lastname: Kaksonen
authors.forename: Peter D
authors.initials: PD
authors.lastname: Franzmann
authors.forename: Jaakko A
authors.initials: JA
authors.lastname: Puhakka
mesh_terms: D018929:Cell Culture Techniques; D002478:Cells, Cultured; D003300:Copper / Q000378:metabolism; D015870:Gene Expression; D045482:Hot Springs / Q000382:microbiology; D006358:Hot Temperature; D010084:Oxidation-Reduction; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D016944:Sulfolobus / Q000145:classification / Q000254:growth & development* / Q000302:isolation & purification; D013455:Sulfur / Q000378:metabolism*; D015003:Yeasts / Q000737:chemistry
chemical_list: D012336:RNA, Ribosomal, 16S; C012819:chalcopyrite; D013455:Sulfur; D003300:Copper