Abstract: Cyanobacteria are mostly distributed in oceans, salt lakes and hypersaline environments. Due to natural selection and genetic differentiation in salt environments, Cyanobacteria have formed special survival mechanisms including in unique community structure composition, diversity distribution and intracellular secondary metabolites. Currently, the diversity, the dominant genus, the salt adaptation mechanism, the species distribution and application of Cyanobacteria need to be further explored from different salt environments. This article systematically reviewed the recent advances in the population diversity, the community structure compositions and the adaptive survival mechanisms(e.g. accumulation of compatible solutes or antioxidants, balance of intracellular ions, and/or increase of antioxidant enzyme activity) of Cyanobacteria among various salt environments. Further, the representative species of intracellular secondary metabolites (e.g. polyketones, oligopeptides/polypeptides, alkaloids, lipids, terpenes and polysaccharides), chemical structure types and main bioactive functions (e.g. antibacterial, anti-inflammatory, antitumor, antimalarial and protease inhibition) were also systematically summarized. It probably provided a reference for subsequent salina algae mining and the utilization of natural metabolites.

Key words: salt environments, Cyanobacteria, dominant taxa, secondary metabolites, bioactive functions