Distribution and role of comammox bacteria in the sediments of Lake Taihu

Nitrification maintains the nitrogen balance in natural ecosystem. The discovery of complete ammonia oxidation (comammox) has broken the traditional theory of "two-step nitrification". However, the comammox bacteria and contribution in lake sediment are little known. Therefore, Lake Taihu was selected for the study, which is a typical freshwater lake with heterogeneity in China. The sediments from five areas with different nutrient levels were selected to investigate the phylogeny and distribution of comammox by amoA gene at different spatial scales, as well as their correlation with environmental factors and the contribution in lake sediment.