The bacterial diversity in different seasons of Miyun Reservoir

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 super(4) per ml by flow cytometry and 10 super(2)-10 super(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 a