Since 2002, MBL has done comprehensive and in-depth researches on sponge microbial symbionts supported by more than ten research projects including four grants from High-Tech Research and Development Program (863) and two grants from National Natural Science Foundation of China (NSFC). Dr. Li has published 27 corresponding-author papers in international SCI journals such as Bioresource Technology, Journal of Bacteriology, Marine Biotechnology, Microbial Ecology, Journal of Experimental Marine Biology and Ecology, Process Biochemistry, and Journal of Applied Microbiology, etc., in addition to 2 book chapters internationally. Some achievements include: 

1. The production of marine natural products: diverse and novel bacteria, actinomycetes and fungi have been isolated from sponges and corals from the South/East China Sea. The efficiency for screening potential strain for producing natural products has been improved by the functional gene (e.g. PKS and NRPS) detection combined with bioactivity assay. Many natural products including marine enzyme with multiple bioactivities have been isolated from sponge-derived bacteria and fungi. With the aim to solve the supply limitation problem for the development of marine drugs, the production yield of natural products has been improved greatly by fermentation optimization; meanwhile, the related biosynthesis mechanism has been revealed. In addition, metagenomics has been used successfully to find novel marine enzymes with biotechnical potentials from uncultured marine microbial symbionts. 

2. The community structure of microbial symbionts: using 454 deep sequencing, gene library and DGGE techniques, diverse bacteria, actinomycetes, cyanobacteria and archaea as well as fungi, algae have been revealed in more than 50 species China Sea sponges and corals. Particularly, the revealed sponge-associated fungi and soft coral-associated actinomycetes extend our knowledge of marine microbial symbionts greatly. Additionally, the spatial specific distribution of bacteria and archaea in sponge cells and mesohyl, cortex layer and endosome section has been suggested. 

3. The community function of microbial symbionts: the metabolic potential and function of the whole symbiontic community of one shallow-water (10-20m) and one deep-sea sponge (1,800m) have been investigated using metagenome-deep sequencing. Meanwhile, nitrogen cycling mediated by sponge and coral-associated bacteria and archaea have been revealed based on functional gene library. These studies provide insight into the close mutualistic relationship between symbionts and host as well as the important roles of sponge and coral-associated microbes in the nitrogen cycle in the oceans.