中国东北条子河中微生物群落变化与锌砷污染的关系研究

研究目的：通过研究河流微生物与污染物的互作关系，为河流污染治理等相关研究提供新途径。创新要点：研究选择的目标河流是报道较少的辽河二级支流，该研究对于了解支流污染特别是东北地区河流污染有重要的意义。将分子生态学技术应用于分析不同污染程度的河流底泥微生物变化，建立微生物种群变化和污染物的互作关系。研究方法：选取沿条子河的8个代表性区段，分析河水和底泥中重金属和污染物的变化情况。通过变性梯度凝胶电泳（DGGE）技术分析不同河流区段内真核和原核微生物种群变化，解析河流中污染物对底泥微生物的影响，建立微生物种群变化和重金属污染的互作关系。重要结论：重金属污染物的存在能抑制底泥中微生物生长，仅少量具有较强抗性的微生物存活（见图4）；有机污染物的增加使对重金属有较强抗性的Limnodrilus hoffmeisteri 大量繁殖（见图2~4），从而大量消耗溶解氧，导致好氧微生物死亡和河水自净能力退化，最终引起水质恶化。由此可见，微生物对环境污染物的变化有很敏感的响应，通过对环境中微生物的监测有助于进一步分析环境污染的变化。

Diversity change of microbial communities responding to zinc and arsenic pollution in a river of northeastern China

Pollution discharge disturbs the natural functions of water systems. The environmental microbial com-munity composition and diversity are sensitive key indicators to the impact of water pol utant on the microbial ecology system over time. It is meaningful to develop a way to identify the microbial diversity related to heavy metal effects in evaluating river pol ution. Water and sediment samples were col ected from eight sections along the Tiaozi River where wastewater and sewage were discharged from Siping City in northeastern China. The main pollutants contents and microbial communities were analyzed. As the primary metal pol utants, zinc （Zn） and arsenic （As） were recorded at the maximum concentrations of 420 and 5.72 μg/L in the water, and 1704 and 1.92 mg/kg in the sediment, re-spectively. These pollutants posed a threat to the microbial community diversity as only a few species of bacteria and eukaryotes with strong resistance were detected through denaturing gradient gel electrophoresis （DGGE）. Acineto-bacter johnsoni , Clostridium cel ulovorans, and Trichococcus pasteuri were the dominant bacteria in the severely pol uted areas. The massive reproduction of Limnodrilus hoffmeisteri almost depleted the dissolved oxygen （DO） and resulted in the decline of the aerobic bacteria. It was noted that the pollution reduced the microbial diversity but the L. hoffmeisteri mass increased as the dominant community, which led to the overconsuming of DO and anaerobic stinking water bodies. Water quality, concentrations of heavy metals, and the spatial distribution of microbial popula-tions have obvious consistencies, which mean that the heavy metals in the river pose a serious stress on the microorganisms.