Collaborative Research: Mediation of Denitrification by Algal/bacterial Interactions in Stream Periphyton: Role of Successional Development and Species Identity

这项研究的主要目标是在一种被称为反硝化的细菌介导的过程中从溪水中去除硝酸盐，在这种过程中，硝酸盐被转化为生物上不活跃的氮气。具体地说，这项工作研究了藻类和细菌薄膜中的这种反硝化过程，这些薄膜被称为生物膜。这项研究将调查溪流和河流中的生物膜何时对去除硝酸盐具有重要意义，其有效性如何随藻类和细菌的种类组成和物种多样性而变化，以及在什么条件下生物膜对硝酸盐的去除是最大的。上个世纪，通过农业径流和化石燃料燃烧产物的大气沉积向水生系统输入的溶解氮急剧增加。地下水中硝酸盐(NO3)含量高对健康构成重大风险，从河流排放到海洋中的NO3负荷增加与沿海地区“死亡区”的形成有关。因此，了解细菌对硝酸盐的调节和去除过程是非常重要的。

The main goals of this research involve removal of nitrate (NO3) from stream water in a bacterially mediated process called denitrification where NO3 is converted to biologically inactive nitrogen gas. Specifically, the work investigates this denitrification process in films of algae and bacteria referred to as biofilms. This research will investigate when biofilms in streams and rivers are of significance in removing nitrates, how the effectiveness varies with the algal and bacterial species composition and species diversity, and under what conditions the nitrate removal by biofilm is maximized. Input of dissolved nitrogen into aquatic systems, via agricultural runoff and atmospheric deposition of products of fossil-fuel combustion, has increased dramatically over the last century. High nitrate (NO3) content in groundwater poses significant health risks, and elevated NO3 loads discharged into the ocean from rivers are implicated in the formation of ''dead zones'' in coastal areas. Thus, understanding the process of this nitrate regulation and removal by bacteria is highly important.