Effects of filter-feeding fish faeces on microbial driving mechanism of lake sediment carbon transformation

Silver carp (Hypophthalmichthys molitrix) can filter the carbon in the food taken up by phytoplankton and plays an important role in carbon fixation. In this study, the faeces of silver carp, the dominant fish species in Qiandao Lake, China, were collected and subjected to a closed incubation and transformation experiment for three months. The physical and chemical indices of water and sediment mixture, carbon metabolic enzyme activity, and microbial sequences were analyzed to identify the key microbial strains that affect carbon transformation as well as the main factors influencing carbon transformation. The results showed maximum CO