Widenfalk Anneli, Bertilsson Stefan, Sundh Ingvar, Goedkoop Willem
Department of Environmental Assessment, Swedish University of Agricultural Sciences, P.O. Box 7050, SE-750 07 Uppsala, Sweden.
Environ Pollut. 2008 Apr;152(3):576-84. doi: 10.1016/j.envpol.2007.07.003. Epub 2007 Sep 5.
A freshwater sediment was exposed to the pesticides captan, glyphosate, isoproturon, and pirimicarb at environmentally relevant and high concentrations. Effects on sediment microorganisms were studied by measuring bacterial activity, fungal and total microbial biomass as community-level endpoints. At the sub-community level, microbial community structure was analysed (PLFA composition and bacterial 16S rRNA genotyping, T-RFLP). Community-level endpoints were not affected by pesticide exposure. At lower levels of microbial community organization, however, molecular methods revealed treatment-induced changes in community composition. Captan and glyphosate exposure caused significant shifts in bacterial community composition (as T-RFLP) at environmentally relevant concentrations. Furthermore, differences in microbial community composition among pesticide treatments were found, indicating that test compounds and exposure concentrations induced multidirectional shifts. Our study showed that community-level end points failed to detect these changes, underpinning the need for application of molecular techniques in aquatic ecotoxicology.
一种淡水沉积物在环境相关浓度和高浓度下暴露于克菌丹、草甘膦、异丙隆和抗蚜威等农药。通过测量细菌活性、真菌和总微生物生物量作为群落水平的终点指标，研究了对沉积物微生物的影响。在亚群落水平上，分析了微生物群落结构（磷脂脂肪酸组成和细菌16S rRNA基因分型，末端限制性片段长度多态性）。群落水平的终点指标不受农药暴露的影响。然而，在较低水平的微生物群落组织中，分子方法揭示了处理引起的群落组成变化。在环境相关浓度下，克菌丹和草甘膦暴露导致细菌群落组成发生显著变化（如末端限制性片段长度多态性所示）。此外，还发现了农药处理之间微生物群落组成的差异，表明测试化合物和暴露浓度引起了多方向的变化。我们的研究表明，群落水平的终点指标未能检测到这些变化，这突出了在水生生态毒理学中应用分子技术的必要性。
