Application Of Bacteroidales 16S RRNA Gene In Tracking The Drinking Water Pollution

Microbial source tracking (MST) is based on the differences of indicator (bacteria or special band ) between environment samples and potential production source, which provides access to track the sources of fecal pollution. Traditional MST methods are complex and time-consuming. In order to explore a quick an easier method, PCR-DGGE based on specific gene 16S rRNA was used to analyze the differences of Bacteroidales communities . Meanwhile, the comparative study of this method and another reported PCR-DGGE method based on Escherichia coli specific gene was conducted.The microbial indicators of the water samples collected for three times from demonstration sites were measured, the, results showed that the number of E.Coli exceeded standard.The drinking water in demonstration sites was contaminated by feces, as for E.Coli was one of fecal pollution indicator organisms.After experiments were repeated, DGGE analysis based on Bacteroidales communities was carried out in the process of experimental conditions ; the concentration of 8% of the gel, denaturing gradient of 35%-65%. The electrophoresis was carried out for 12 hours in the voltage of 60 V.Microbial source tracking method based on the specific gene of Bacteroidales communities was established through research.Microbe was collected by filter membranes, and then the filter membranes were grinded in liquid nitrogen and DNA extracted by CTAB.method Bacteroidales specific DNA amplications were separated by the primer Bac32F/Bac708R, the group differences between the different samples were detected by a nest-PCR based on V3 area of 16S rRNA. which suggested the similarity among different samples. Then the method was applied to ananlyze the samples collected at different times, which also verified the method, the results were consistant with the actual situation.In this study Bacteroidales specific primers were used in PCR-DGGE method to trace the difference Bacteroidales among different water samples. The source of water pollution could be determined by this method effectively and reliably. Comparing with another method based on E. coli specific genes, this method was more value in the application of MST methods.As one of fecal pollution indicators, the presence of Bacteroidales illustrated that the water samples were contaminated by feces. The results by microbial source tracking showed that the drinking water was polluted by the pond around, for Bacteroidales community characteristics of drinking water and the pond water were similar. Well water is a typical source of drinking water in rural areas in South China. This kind of drinking water was suffering from the pollution of pond water, water remediation should be taken effectively and timely.