Lawrence John R, Swerhone George D W, Topp Edward, Korber Darren R, Neu Thomas R, Wassenaar Leonard I
Environment Canada, Saskatoon, Saskatchewan S7N 3H5.
Environ Toxicol Chem. 2007 Apr;26(4):573-82. doi: 10.1897/06-340r.1.
Diclofenac is a nonsteroidal anti-inflammatory drug (NSAID) that has been detected widely in surface waters in North America and Europe. The impact of diclofenac on river biofilm communities was investigated at exposures of 10 and 100 microg L(-1) of diclofenac or its molar equivalent in carbon and nutrients. Experiments were carried out with river water during spring and summer using rotating annular reactors as model systems. Diclofenac or nutrients at 10 microg L(-1) were observed to have no significant effect on algal, bacterial, and cyanobacterial biomass in spring, whereas in the summer the nutrient equivalent reduced algal biomass and diclofenac reduced cyanobacterial biomass relative to control biofilms (p < 0.05). In contrast, at 100 microg L(-1) diclofenac or nutrients, the result was increased cyanobacterial and bacterial biomass, respectively, relative to control biofilms in spring. In summer, 100 microg L(-1) diclofenac significantly increased bacterial biomass and the nutrient treatment had no significant effect (p < 0.05); both treatments resulted in increased biofilm thickness. The glycoconjugate composition of the exopolysaccharide matrix was influenced differentially by the treatments in both seasons. Biolog assessments of carbon use indicated that 100 microg L(-1) diclofenac or nutrients resulted in significant depressions in the use of carbon sources in summer and significant increases in spring. Impacts on protozoan and micrometazoan populations also were assessed. Denaturing gradient gel electrophoresis analyses of community DNA and fluorescent in situ hybridization studies indicated that diclofenac had significant effects on the nature of the bacterial community in comparison with control and nutrient-treated river biofilm communities.
双氯芬酸是一种非甾体抗炎药（NSAID），在北美和欧洲的地表水中被广泛检测到。在双氯芬酸浓度为10和100微克/升或其碳和营养物摩尔当量的暴露条件下，研究了双氯芬酸对河流生物膜群落的影响。在春季和夏季，使用旋转环形反应器作为模型系统，以河水进行实验。在春季，观察到10微克/升的双氯芬酸或营养物对藻类、细菌和蓝藻生物量没有显著影响，而在夏季，相对于对照生物膜，营养物当量降低了藻类生物量，双氯芬酸降低了蓝藻生物量（p < 0.05）。相比之下，在春季，100微克/升的双氯芬酸或营养物导致蓝藻和细菌生物量相对于对照生物膜分别增加。在夏季，100微克/升的双氯芬酸显著增加了细菌生物量，营养物处理没有显著影响（p < 0.05）；两种处理都导致生物膜厚度增加。在两个季节中，处理对胞外多糖基质的糖缀合物组成有不同的影响。碳利用的Biolog评估表明，100微克/升的双氯芬酸或营养物在夏季导致碳源利用显著下降，在春季则显著增加。还评估了对原生动物和微型后生动物种群的影响。群落DNA的变性梯度凝胶电泳分析和荧光原位杂交研究表明，与对照和营养物处理的河流生物膜群落相比，双氯芬酸对细菌群落的性质有显著影响。
