The process of urbanization aggravates the endogenous pollution of urban lake sediment, and polluted sediment may seriously affect the quality of the water in lakes. At present, it is difficult to distinguish the difference between sediment that is heavily polluted by nitrogen (N) and phosphorus (P) when using an analysis based on a physicochemical index classification. The current study applied phospholipid fatty acid (PLFA) technology to further analyze the sediment characteristics from the perspective of microbiology. Surface sediment from five urban lakes that are heavily polluted with N and P in Wuhan were sampled. Statistical approaches were used to analyze the microbial community structure in the sampled sediment, and to determine the correlations between the microorganisms and physicochemical indices. The most severely polluted lake sediment had similar PLFA structures, the highest saturated fatty-acid content, and bacteria as the dominant microorganism. However, there were differences between the microbial biomass of the various sediment samples, which may have been related to the degree of N and P pollution. Analysis of the microbial diversity in the sediment samples indicated that the bacteria were experiencing starvation and nutrient pressure, which may have been due to the dissolved oxygen concentration of the heavily polluted lake sediment. A correlation analysis showed that the endogenous N and P had different effects on the microbes of the polluted sediment. A redundancy analysis (RDA) demonstrated that the N/P ratio had the greatest influence on the PLFA species, accounting for 83% of the cumulative interpretation. To effectively promote the role of sediment microorganisms on circulating elements, it is necessary to regulate the N/P ratio of the sediment to some extent. When the N/P ratio in sediment exceeds 6, N pollution should be prioritized.

城市化进程加剧了城市湖泊沉积物的内源性污染，污染的沉积物可能严重影响湖泊的水质。目前，当使用基于理化指标分类的分析时，很难区分被氮（N）和磷（P）严重污染​​的沉积物。当前的研究应用磷脂脂肪酸（PLFA）技术从微生物学的角度进一步分析沉积物特征。武汉市五个城市湖泊的表层沉积物被氮和磷污染严重。统计方法用于分析采样沉积物中的微生物群落结构，并确定微生物与理化指标之间的相关性。污染最严重的湖泊沉积物具有相似的PLFA结构，最高的饱和脂肪酸含量，并且细菌是优势微生物。但是，不同沉积物样品的微生物量之间存在差异，这可能与氮和磷污染程度有关。对沉积物样品中微生物多样性的分析表明，细菌正处于饥饿和营养压力状态，这可能是由于污染严重的湖泊沉积物中的溶解氧浓度所致。相关分析表明，内源氮和磷对污染沉积物微生物的影响不同。冗余分析（RDA）表明，N / P比对PLFA种类的影响最大，占累积解释的83％。为了有效促进沉积物微生物对循环元素的作用，有必要在一定程度上调节沉积物的N / P比。当沉积物中的N / P比超过6时，应优先考虑N污染。