The Study On Microbial Pollution Source Tracking For Water In The Pearl River Delta Region

Livestock and poultry feces are one of the main factors leading to water pollution in China.For this reason,accurate source identification is particularly important in pollution control and management.In recent years,MST(Microbial Source Tracking)technology has emerged after Europe and other developed countries carrying out a study on the use of microbes to trace the origin of water feces pollution.This technique provides new ideas for rapid identification of pollution sources,but the presence of specific biomarkers is always single and regional differences is another limitation.In this project,fecal pollution source at Pearl River Delta region(PRD)were investigated.Using the method of Microbial Source Tracking technology,extensive animal stool samples were collected as well as efficient extraction of genomic DNA in these samples.Bacteroides specific primers which has achieved some success in other regions through the literature were identified.Also,Genomic DNA extracted from stool samples in different host were used as templates to test the specificities of these primers in the Pearl River Delta region.Meanwhile,water samples were analyzed to confirm the possibility of Microbial Source Tracking of surface water.Results of 105 stool samples and 8 water samples from Guangzhou Baiyun District,Luogang District,Yuexiu District,Huizhou City and Qingyuan City showed that Bacteroides universal primer Bac32F/Bac708 R,human Bacteroides biomarker specific primers HF134 F /Bac708 R and HF183/Bac708 R,pig Bacteroides biomarker specific primer PF163F/Bac708 R and chicken Bacteroides biomarker specific primer CBR2-42F/ CBR2-42 R have good specificity in the Pearl River Delta region.By using these specific primer pairs to identify and analyze water of known pollution sources,evidence for traceability of microbial contamination of surface water in the Pearl River Delta region could be provided.For sustained attenuation characteristics of biomarkers in the environment,this paper established standard curves for quantitative research aimed to chicken Bacteroides biomarker specific primer qC160F-HU/qBac265R-HU,Bacteroides general biomarker primer GenBac3F/GenBac3 R,bacterial biomarker primer BACT1369F/PROK1541 R and E.coil general biomarker primer EC23S857F/EC23S857 R.It is confirmed that they have good specificity in the PRD region.In this study,a water environmental simulation system was established.By controlling the value of a single variable dissolved oxygen,research on the difference of microbiological and environmental indicators in aerobic and anaerobic environment were engaged.During therunning of water environment simulation system,the turbidity of aerobic environment declined from 6.69 NTU to 3.36 NTU,COD of aerobic environment declined from 38.5mg/L to 15mg/L.However,the turbidity of anaerobic environment rised from 7.18 NTU to 9.23 NTU,COD of anaerobic environment declined from 42mg/L to 40mg/L.The self purification capacity of water in aerobic environment was higher than that of anaerobic environment.Meanwhile,the detection results of microbial indicators in water environment simulation system revealed that the number of Bacteroides was higher than that of E.coli in chicken feces.Not all Bacteroides in chicken feces had the chicken-specific Bacteroides biomarker.By analyzing of environmental indicators and microbial indicators,two stages of survival and death were found from the presence of Bacteroides and E.coli in anaerobic water environment.The decay of biomarkers in different stages of were different.In conclusion,in the study of the biological marker attenuation,the bacterial activity detection technology should be introduced.