Abstract:With the development of eutrophication in freshwater lakes in the past decades, harmful cyanobacteria blooms (CyanoHABs) have become more frequent and with worse extends around the world. Many of these CyanoHABs produce cyanotoxins, often microcystins (MCs), and threaten human health and the environments, MCs are chemically stable, however they can be effectively degraded through microbial process, which has a great potential in applications for environment-friendly water treatments and environmental protection. In this review, we summarized the chemical structure, toxicity and degradation of microcystins, with the emphasis on microbial decomposition processes of microcystins and their potential application in water treatment and environmental protection.