Analysis Of Microbes Community's Structure Spatial Changes In Contaminated River

Using microbes in situ existing in environment to treat and restore contaminated water is not only economic but also a kind of green technology which could avoid secondary pollution. Therefore to fully understand the absolute quantification and the community structure of those microbes in contaminated rivers , not only can determine the impact of pollutants on water environment, but also plays a important part in contaminated river treatment and improving the efficiency of self-purification by the participation of human to change environmental conditions. In recent years, with the increasing maturation of molecular biology technique and its application in detection and analysis of the environmental microbes, the determination of natural microbes population in water environment and their absolute quantity in situ has come true.This research took one contaminated section of Second Songhua River through Jilin City as the study object. First of all, SS and COD of collected water samples are determined immediately as the samples are sent to the laboratory, and then extract 16S rRNA which is from those water samples and attached biofilms samples and is highly conservative and maintains a high degree of "family-specific" sequence or structure for microbes in long-term evolution. Subsequently we amplified them by conventional PCR and also purified those DNA samples. After purification, we determine absolute concentrations of these DNA samples by four steps of Real-time PCR. We used cloning to identify microorganisms'species after DNA purification and determined them in NCBI GeneBank, and established 16S rRNA Gene Library subsequently. Through detection of the absolute quantification of microbes, identification of microorganisms'species and conventional tests for contaminated river water quality, we discussed the relations between microbes and water quality spatial changes and got another perspective to reveal the role played by microbes in water self-purification.The results showed that the attached microorganisms were mainly Melosira varians which could stand low temperature and love nutrition enriched environment. This result showed that the composition of microbes in the study section was a little single. While in upstream which was used as background, we detected Aeromonas which is a kind of pathogenic bacteria and instructed that the upstream has been polluted. Planktonic and attached microbes reproduced in large during 50-100m along the river and 20-90m in horizontal direction. And the amount of attached microbes reached a peak at 100m downstream, which was 46.2μg/μl.