太湖水体附着细菌和浮游细菌的丰度与分布特征

为了探讨太湖水体附着细菌及浮游细菌丰度的变化规律,明确细菌丰度与环境因子的关系,应用荧光显微技术对太湖4个湖区细菌丰度及分布特征进行了研究,并探讨了其与总氮(TN)、总磷(TP)、叶绿素a(Chla)、总悬浮颗粒物(TSS)等环境因子之间的关系.结果表明,太湖水体中附着细菌占优势,占总细菌的65％(总细菌平均值为6.53×106cells/mL,附着细菌平均值为4.25×106 cells/mL,浮游细菌平均值为2.28 × 106 cells/mL);附着细菌与浮游细菌数丰度具有相似的时空分布规律,附着细菌与浮游细菌丰度都是河口区(10#)最高,其次梅梁湾(3 #)、湖心区(8#)和东太湖(24#)较低;春夏季高,秋冬季低;水温、TP对太湖水体中附着细菌及附浮游细菌的丰度影响比较大,它们与水体中附着细菌丰度及附浮游细菌均呈显著的正相关(p＜0.05).太湖不同湖区附着细菌及浮游细菌的数量空间差异是由太湖不同湖区生态环境的异质性引起的.

Abundance and distribution of particle-attached bacteria and free-living bacteria in Lake Taihu

Fluorescence microscopic technology was used to study the abundance and distribution of particle-attached bacteria and free-living bacteria in four areas of Lake Taihu. The objectives of this study were to explore the temporal and spatial change of the abundance of particle-attached bacteria and free-living bacteria, and the correlation between bacteria and environmental factors such as TN, TP, Chla and TSS. The results showed that particle-attached bacteria were the dominant forms in Lake Taihu, accounting for 65% of the total bacteria (the average abundance of the total bacteria was 6.53×10⁶ cells/mL,the average abundance of particle-attached bacteria was 4.25×10⁶ cells/mL,the average abundance of free-living bacteria was 2.28×10⁶ cells/mL). Temporal and spatial dynamics of them were that the average abundances of particle-attached bacteria and free-living bacteria were highest in the site of river inlet(10^#),followed by in the site of Meiliang bay(3^#),while lower in East Taihu(24^#) and central areas of the lake(8^#). Abundances of them were higher in spring and summer, while lower in autumn and winter. The abundance of particle-attached bacteria and free-living bacteria were positively related to water temperature, TP, respectively. The spatial dynamics of bacteria from Lake Taihu were due to eco-environmental heterogeneity in different areas of the lake.