中文摘要：

以云南抚仙湖为研究对象,分析了不同污染来源沉积物微生物量、碱性磷酸酶活性（APA）和微生物解磷能力的垂向分布特征和水平分布特征.结果表明,抚仙湖各采样点沉积物微生物生物量与APA垂向分布趋势相似,总体上随着深度增加逐渐降低,微生物作用主要表现在表层.在空间分布上,富营养化星云湖以泄水为主的南岸隔河口微生物生物量和APA最高,其次为以农业面源污染为主的北岸梁王河口和以磷矿开发为污染来源的北岸东大河口,再次为受人类活动影响较小、以自生有机污染为主的湖心和东岸老凹嘴,以自然水土流失为主的西岸尖山河口微生物生物量和APA最低.沉积物微生物生物量和APA体现了不同外源污染对抚仙湖各湖区的影响不同.抚仙湖沉积物微生物对有机磷和无机磷均有解磷能力,并且无机磷解磷能力大于有机磷.沉积物解无机磷细菌数量和APA决定了抚仙湖沉积物磷释放强度,造成了抚仙湖较高强度的内源磷污染负荷.

英文摘要：

The vertical variations of microbial biomass,alkaline phosphatase activity（APA） and phosphate-solubilizing ability of microbes were studied in the sediments from different pollution sources in Lake Fuxian,Yunnan Province.The results showed that the microbial biomass and the APA in the sediment cores generally decreased with the depth and the strongest microbial activity was shown in the surface sediment.The microbial biomass and the APA in the sediments of the mouth of Gehe River in the south shore were the highest among the research sites,which was heavily polluted by the discharge from eutrophic Lake Xingyun.The second highest amounts of the microbial biomass and the APA were found in the sediments of the mouth of Liangwan River with agriculture pollution source and the sediments in the mouth of Dongda River with phosphate mining pollution source.However,the lowest amounts of the microbial biomass and the APA were shown in the sediments of the mouth of Jianshan River with the pollution source of soil erosion.The result of incubation experiment showed that the microbes in the sediments had stronger phosphate-solubilizing ability to dissolve inorganic phosphate than to dissolve organic phosphate.The combination of the amount of inorganic phosphate solubilizing bacteria and the APA determined the potential of phosphorus releasing from sediment,which resulted in high interior phosphorus loading in Lake Fuxian.