Characterization of Microbial Community and Phosphorus-releasing Bacteria in the Sediments of a Eutrophic Shallow Lake, Eastern China

To understand the interactions between phosphorus (P) and microbial community and characterize some P-releasing bacteria, ten representative sediment samples were collected in a small eutrophic lake and a clean wetland. Total P concentration in wetland sediment was much lower than that in the lake, while NaOH-extractable P was relatively high in wetland which indicated high releasable risk. According to Standards Measurements and Testing Program of the European Commission (SMT protocol), P in lake rooted in agricultural runoff and P in wetland was mainly of anthropogenic origin, and the microbial communities were significantly different between these two kinds of sediment. Enumeration of inorganic P-releasing bacteria (IPB) and organic P-releasing bacteria (OPB) showed these groups were not very rich in the ecosystem. Molecular identification indicated there were various kinds of bacteria involved in the P transition cycle, but the P release abilities of different bacteria were dissimilar.