高原湖泊沉积物中反硝化微生物的群落特征——以包头南海湖为例

为了探明内蒙古高原富营养化城市湖泊中nirS型反硝化细菌群落结构的特异性，利用特异性功能基因nirS对包头市南海湖的表层沉积物进行反硝化细菌多样性测定，在分析各采样点沉积物理化指标的基础上，对各样品中nirS型反硝化细菌群落和多样性进行研究.结果表明，南海湖沉积物Shannon指数变化为3.07~3.41，相比于其他研究，反硝化微生物多样性相对较低.参与反硝化的优势菌属与大多数湖泊保持一致，以假单胞菌属（Pseudomonas）和红杆菌属（Rhodobacter）为主.冗余分析（RDA）指出，城市湖泊中的各种类型的污染物对反硝化优势菌属有明显的促进作用，红杆菌属（Rhodobacter）与硝酸盐氮、亚硝酸盐氮呈正相关，假单胞菌属（Pseudomonas）除受硝酸盐氮、亚硝酸盐氮的影响外，还与总磷呈较强的正相关.南海湖nirS型反硝化细菌中的主要菌属促进了反硝化作用，加速了南海湖氮素的去除.

Community characteristics of denitrifying microorganisms in plateau lake sediments-taking Nanhaihu lake as example

In order to investigate the characteristics of the nirS-type denitrification bacteria structure of eutrophic urban lakes in Inner Mongolia Plateau, a specific functional gene nirS was measured to determine the denitrifying bacterial diversity in the surface sediments of Nanhai Lake, Baotou. Based on the physicochemical indexes analysis of the sediments at each sampling point, the nirS-type denitrifying bacteria community and diversity were studied. Results showed that the Shannon Index ranged from 3.07 to 3.41. Comparing with other studies, biodiversity of denitrifying bacteria was relatively low and the dominant bacteria involved in the denitrification remained the same as most of the lakes with genera Pseudomonas and Rhodobacter being the majorities. The redundant analysis (RDA) indicated that various types of pollutants in the urban lake exerted significantly promotive effects on the denitrifying bacteria. Rhodobacter was positively correlated with nitrate nitrogen (NO₃^--N) and nitrite nitrogen (NO₂^--N), and Pseudomonas presented a strong positive correlation with total phosphorus (TP) in addition to nitrate nitrogen (NO₃^--N) and nitrite nitrogen (NO₂^--N). The main bacteria among the nirS-type denitrifying bacteria in Nanhai Lake promoted the denitrification thus accelerated the removal of nitrogen.