密云水库不同季节细菌群落多样性

The bacterial diversity in different seasons of Miyun Reservoir

为加强对密云水库水体状况的全面了解,对2006年11月到2007年11月不同季节水体中的微生物进行了研究。用流式细胞仪技术和LB固体培养基培养测定了水体中的细菌数目;利用PCR-DGGE技术对水体细菌的多样性和相似性进行分析。结果表明,细菌数目随季节变化有所不同,但利用流式细胞仪测定的每毫升水体细菌的数目基本上均为104数量级,而培养得到的细菌菌落数为102～103CFU/ml,基本符合国家饮用水源的卫生标准。细菌的多样性指数也表现出随季节变化的规律,冬季(2006-11和2007-11)Shannon-Weaver多样性指数较低,为3.0左右;春季(2007-04)开始增大,至夏季(2007-07)时可高达3.3068;秋季(2007-09)又减小到3.1246。另外,密云水库细菌的优势类群有β-Proteobacteria、Actinobacteria、Cytophaga/Flexibacter/Bacteroides(CFB)类群和Cyanobacteria。这些资料有望为以后进一步从微生物角度评价水质提供参考。

In this study, we evaluated the bacterial populations in Miyun Reservoir in different seasons from Nov. 2006 to Nov. 2007 to determine the overall water quality of the reservoir. The bacterial counts in water samples collected from the reservoir were determined by flow cytometry and by culture in LB medium. In addition, the bacterial diversity and dominant groups were also evaluated by PCR-DGGE. The results revealed that the bacterial counts were different according to theseason, but that the average counts, which were determined to be 10^4 per ml by flow cytometry and 10^2-10^3 CFU per ml by culture in LB medium, were below the national standards for resource water. In addition, determination of the bacterial Shannon-Weaver diversity index revealed that the diversity also varied by season. Specifically, diversity was very low inwinter （ approximately 3.0 in November 2006 and 2007 ）, （April and July, 2007） , after which it began to decrease, but increased to as high as 3. 3068 in the spring and summer with ：a value of 3. 1246 being observed in autumn （September 2007 ）. Furthermore, the dominant groups of bacteria observed in Miyun Reservoir included β-Proteobacteria, Aetinobaeteria, Cytophaga/Flexibacter/Bacteroides （CFB） phylum and Cyanobacteria. Taken together, the results of this study will help to understand future changes in the water quality of Miyun Reservior.