Garcia-Armisen Tamara, Servais Pierre
Ecologie des Systèmes Aquatiques, Université Libre de Bruxelles, Bruxelles, Belgique.
Water Environ Res. 2009 Jan;81(1):21-8.
Attachment of fecal bacteria to suspended matter in the water column has important implications for its fate in rivers. We examined the part of Escherichia coli (E. coli) associated with suspended matter in natural river water samples, using a combination of 5-microm filtration and beta-D-glucuronidase (GLUase) assay to estimate the E. coli abundance and attachment. We observed that the fraction of particle-associated E. coli was positively correlated with suspended matter concentration. The settling rate of particle-associated E. coli was found to be positively correlated with suspended matter concentration for samples with suspended matter content lower than 50 mg/L. For samples with higher suspended matter concentration, the settling rate was quite constant (0.066 m/h, on average). In batch experiments using river waters, we observed that free E. coli had a decay rate approximately 2 times higher than particle-associated E. coli. This information can be used to improve the models on the fate of E. coli in rivers.
粪便细菌附着于水柱中的悬浮物对其在河流中的归宿具有重要意义。我们结合使用5微米过滤法和β-D-葡萄糖醛酸酶（GLUase）测定法，来估计天然河水样本中与悬浮物相关的大肠杆菌（E. coli）的比例，以此检测大肠杆菌的丰度和附着情况。我们观察到，与颗粒相关的大肠杆菌比例与悬浮物浓度呈正相关。对于悬浮物含量低于50毫克/升的样本，与颗粒相关的大肠杆菌的沉降速率与悬浮物浓度呈正相关。对于悬浮物浓度较高的样本，沉降速率相当恒定（平均为0.066米/小时）。在使用河水的批次实验中，我们观察到游离的大肠杆菌的衰减速率比与颗粒相关的大肠杆菌高出约2倍。这些信息可用于改进大肠杆菌在河流中归宿的模型。
