title: Sulfolane degradation by mixed cultures and a bacterial isolate identified as a Variovorax sp.
abstract: Sulfolane (tetrahydrothiophene-1,1-dioxide) is used in the Sulfinol process for natural gas sweetening. At many sour-gas processing plants spills, landfills and leakage from unlined surface storage ponds have contaminated groundwaters with sulfolane. Due to its high water solubility and mobility in aquifers, sulfolane poses a risk for off-site contamination. This study investigated the aerobic biodegradation of sulfolane by two mixed microbial enrichment cultures and by three bacterial isolates. Sulfolane served as the sole C, S and energy source for these cultures. In the two mixed cultures, 60% and 80% of the sulfolane C was recovered as CO2, whereas in cultures of the three isolates only 40-42% of the substrate C was recovered as CO,. In the mixed cultures, 81% and 97% of the sulfolane S was converted to sulfate, and in the pure isolates, 55-90% of the substrate S was converted to sulfate. Thus, the mixed cultures were capable of greater mineralization than the pure isolates. One isolate, strain WP1, was identified using a combination of 16S rRNA gene sequencing, physiological traits and cell morphology. WP1 was determined to be most similar to Varioivorax paradoxus.
authors.affiliation: Department of Biological Sciences, University of Alberta, Edmonton, Canada.
authors.forename: E A
authors.initials: EA
authors.lastname: Greene
authors.forename: P H
authors.initials: PH
authors.lastname: Beatty
authors.forename: P M
authors.initials: PM
authors.lastname: Fedorak
mesh_terms: D000332:Aerobiosis; D001483:Base Sequence; D020562:Betaproteobacteria / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D001673:Biodegradation, Environmental; D017931:DNA Primers / Q000235:genetics; D005579:Fossil Fuels; D005798:Genes, Bacterial; D012329:RNA, Bacterial / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D013447:Sulfites / Q000378:metabolism; D013876:Thiophenes / Q000378:metabolism*; D014871:Water Microbiology; D014874:Water Pollutants, Chemical / Q000378:metabolism*
chemical_list: D017931:DNA Primers; D005579:Fossil Fuels; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S; D013447:Sulfites; D013876:Thiophenes; D014874:Water Pollutants, Chemical; C013693:sulfolane