Géosciences Rennes, UMR CNRS-Université de Rennes I, Campus de Beaulieu, batiment 15 bureau 306/2, 35042 Rennes Cedex, France.
Water Res. 2012 Sep 1;46(13):4009-16. doi: 10.1016/j.watres.2012.05.003. Epub 2012 May 18.
Improving the microbiological quality of coastal and river waters relies on the development of reliable markers that are capable of determining sources of fecal pollution. Recently, a principal component analysis (PCA) method based on six stanol compounds (i.e. 5β-cholestan-3β-ol (coprostanol), 5β-cholestan-3α-ol (epicoprostanol), 24-methyl-5α-cholestan-3β-ol (campestanol), 24-ethyl-5α-cholestan-3β-ol (sitostanol), 24-ethyl-5β-cholestan-3β-ol (24-ethylcoprostanol) and 24-ethyl-5β-cholestan-3α-ol (24-ethylepicoprostanol)) was shown to be suitable for distinguishing between porcine and bovine feces. In this study, we tested if this PCA method, using the above six stanols, could be used as a tool in "Microbial Source Tracking (MST)" methods in water from areas of intensive agriculture where diffuse fecal contamination is often marked by the co-existence of human and animal sources. In particular, well-defined and stable clusters were found in PCA score plots clustering samples of "pure" human, bovine and porcine feces along with runoff and diluted waters in which the source of contamination is known. A good consistency was also observed between the source assignments made by the 6-stanol-based PCA method and the microbial markers for river waters contaminated by fecal matter of unknown origin. More generally, the tests conducted in this study argue for the addition of the PCA method based on six stanols in the MST toolbox to help identify fecal contamination sources. The data presented in this study show that this addition would improve the determination of fecal contamination sources when the contamination levels are low to moderate.
提高沿海和河流水质的微生物质量依赖于开发能够确定粪便污染来源的可靠标志物。最近，一种基于六种甾醇化合物（即 5β-胆甾烷-3β-醇（粪甾烷醇）、5β-胆甾烷-3α-醇（胆甾烷醇）、24-甲基-5α-胆甾烷-3β-醇（菜甾烷醇）、24-乙基-5α-胆甾烷-3β-醇（豆甾烷醇）、24-乙基-5β-胆甾烷-3β-醇（24-乙基粪甾烷醇）和 24-乙基-5β-胆甾烷-3α-醇（24-乙基胆甾烷醇））的主成分分析（PCA）方法被证明适合区分猪和牛的粪便。在本研究中，我们测试了这种 PCA 方法，使用上述六种甾醇，是否可以作为“微生物源追踪（MST）”方法的工具，用于农业密集地区的水中，这些地区的粪便污染通常由人类和动物来源的共存所标记。特别是，在 PCA 得分图中，沿着已知污染来源的“纯”人、牛和猪粪便以及径流和稀释水聚类样本时，发现了定义明确且稳定的聚类。基于 6-甾醇的 PCA 方法和用于受未知来源粪便污染的河水的微生物标记物之间的源分配也具有很好的一致性。更一般地，本研究中的测试表明，在 MST 工具包中添加基于六种甾醇的 PCA 方法有助于识别粪便污染来源。本研究中提供的数据表明，当污染水平较低至中等时，这种添加将提高粪便污染来源的确定。
