Lee D M, Guckert J B, Ventullo R M, Davidson D H, Belanger S E
Biology Department, University of Dayton, Ohio 45469, USA.
Ecotoxicol Environ Saf. 1997 Apr;36(3):288-96. doi: 10.1006/eesa.1996.1518.
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.
在一项为期8周的溪流中宇宙研究中，测定了连续暴露于C12 - 烷基硫酸盐对附生微生物群落的影响。C12 - 烷基硫酸盐浓度范围从与环境相关的（<10 - 20微克/升）到不切实际的高浓度（>1500微克/升）。评估的终点包括周转率、细菌细胞密度、异养混合氨基酸摄取以及脂肪酸谱评估。预先投加的周丛生物对C12 - 烷基硫酸盐的平均周转率为0.08/小时。在为期8周的投药期内，在投加≥61微克C12 - 烷基硫酸盐/升的溪流中，尽管溪流温度下降了10摄氏度，但平均周转率仍显著增加。还观察到周转率与C12 - 烷基硫酸盐浓度之间存在显著相关性。虽然在研究期间细菌细胞密度增加，但确定对C12 - 烷基硫酸盐的生物降解适应并非生物量特异性的。同样，细菌活性在整个研究过程中总体上有所增加，但它与生物降解或细菌细胞密度均无相关性。最后，磷脂脂肪酸谱表明，与对照溪流相比，高剂量溪流中的微生物群落发生了转变。这项研究表明，C12 - 烷基硫酸盐在与环境相关的浓度下会迅速降解并诱导生物降解适应反应。
