title: Stream periphytic biodegradation of the anionic surfactant C12-alkyl sulfate at environmentally relevant concentrations.
abstract: The effects of continuous exposure to C12-alkyl sulfate on a periphytic microbial community were determined in an 8-week stream mesocosm study. C12-alkyl sulfate concentrations ranged from environmentally relevant (< 10-20 micrograms/liter) to unrealistically high concentrations (> 1500 micrograms/liter). Endpoints evaluated included turnover rates, bacterial cell density, heterotrophic mixed amino acid uptake, and fatty acid profile evaluations. Predosed periphyton demonstrated a mean turnover rate for C12-alkyl sulfate of 0.08/hr. During the 8-week dosing period, a significant increase in mean turnover rates was observed in streams dosed with > or = 61 micrograms C12-alkyl sulfate/liter, despite a 10 degrees C drop in stream temperature. A significant correlation between turnover rate and C12-alkyl sulfate concentration was also observed. While bacterial cell density increased during the study, it was determined that the biodegradation acclimation to C12-alkyl sulfate was not biomass-specific. Likewise, bacterial activity generally increased over the study, but it did not correlate with either biodegradation or bacterial cell density. Lastly, phospholipid fatty acid profiles indicate that a shift in the microbial community occurred in the high-dose stream as opposed to the control stream. This study demonstrates that C12-alkyl sulfate is rapidly degraded and induces a biodegradative acclimation response at environmentally relevant concentrations.
authors.affiliation: Biology Department, University of Dayton, Ohio 45469, USA. leedm1@pg.com
authors.forename: D M
authors.initials: DM
authors.lastname: Lee
authors.forename: J B
authors.initials: JB
authors.lastname: Guckert
authors.forename: R M
authors.initials: RM
authors.lastname: Ventullo
authors.forename: D H
authors.initials: DH
authors.lastname: Davidson
authors.forename: S E
authors.initials: SE
authors.lastname: Belanger
mesh_terms: D000596:Amino Acids / Q000378:metabolism; D001419:Bacteria / Q000254:growth & development; D001673:Biodegradation, Environmental; D018533:Biomass; D005227:Fatty Acids / Q000032:analysis / Q000378:metabolism; D010743:Phospholipids / Q000032:analysis / Q000378:metabolism; D010944:Plants / Q000378:metabolism*; D012967:Sodium Dodecyl Sulfate / Q000378:metabolism*; D013501:Surface-Active Agents / Q000378:metabolism*; D013696:Temperature; D014871:Water Microbiology
chemical_list: D000596:Amino Acids; D005227:Fatty Acids; D010743:Phospholipids; D013501:Surface-Active Agents; D012967:Sodium Dodecyl Sulfate