浑河底泥微生物群落的季节性变化特征

为了解河流底泥微生物群落结构的季节性变化,利用PCR-DGGE技术对丰水期、平水期、枯水期浑河底泥中的微生物进行指纹图谱分析,并对优势条带进行测序和系统发育分析. 结果表明:浑河底泥微生物群落结构存在一定的时空异质性,在空间上可分为上游抚顺市地区(1~5号采样点)、中游沈阳市地区(6~11号采样点)和下游乡镇地区(12~14号采样点)；平水期、枯水期、丰水期Shannon-Wiener多样性指数分别为3.04~3.88、2.66~3.66、3.04~3.45. 抚顺市地区和沈阳市地区不同水期底泥微生物Shannon-Wiener多样性指数差异较大,而乡镇地区则无明显变化趋势；平水期和枯水期底泥微生物Shannon-Wiener多样性指数从上游至下游呈先升后降趋势,而丰水期上、下游微生物多样性差异较小. 底泥微生物中以变形菌(Proteobacteria)最多,其次是拟杆菌(Bacteroidetes)和蓝藻菌(Cyanobacteria)；而平水期优势种群数量最多. 研究显示,人类活动及丰水期对底泥微生物多样性有较大影响,掌握河流底泥微生物分布有助于深入了解河流物质的代谢过程. 

Seasonal Changes of Microbial Community Distribution in Sediments of Hun River

Abstract: In order to investigate the impact of seasonal changes on the microbial community in the sediment of the Hun River, denaturing gradient gel electrophoresis (PCR-DGGE) was used to analyze the diversities and spatial distributions of the microbial community in the normal season, dry season and wet season, respectively. Correspondingly, the predominance bands were sequenced and analyzed based on the phylogenetic tree. The results showed that the Hun River could be divided into three sections, namely the upstream section (in Fushun City), the midstream section (in Shenyang City) and the downstream section (in the rural area), based on the microbial community similarity along the sediment of the river. The microbial Shannon-Wiener indexes were 3.04-3.88,2.66-3.66,3.04-3.45 in the normal season, dry season and wet season, respectively. The indices had an obvious variation when the river flowed through the city area, but were stable when flowing through the rural area. The tendency of microbial diversity, namely gradually increasing in the upstream and midstream and decreasing in the downstream, could be observed in the normal season and dry season, but disappeared in the wet season. In the sediments of the Hun River, Proteobacteria, Bacteroidetes and Cyanobacteria were the dominant microbes. Therefore, microbial distribution in the sediment of the Hun River has significant changes in different seasons. Investigating the microbial distribution in river sediment is of importance to understanding the materials cycling in rivers.