Advances in the mercury tolerance mechanisms of cyanobacteria

Abstract:

Cyanobacteria have strong capacities of tolerance and accumulation for different speciations of mercury, make the concentrations of different mercury-speciations convert and influence the biogeochemical cycling of mercury. Meanwhile, the various mecury-speciations accumulated by cyanobacteria which are significant primary producers in the ecosystem, are more easily delivered into the food chain, which affects human health. This paper systematically summarized the mechanisms of mercury tolerance of cyanobacteria, which included: (1) synthesizing a colloidal sheath outside the cell wall to isolate mercury; (2) mercury stabilization by combining with their own compounds; (3) using their own antioxidant mechanisms to repair the damage of mercury to cells; (4) using their own enzymes to transform the form of mercury to reduce toxicity; (5) symbiosis with mercury-resistant bacteria to resist mercury. On the basis of the above, this paper gave prospects of the further research directions of mercury-tolerance mechanisms for cyanobacteria, the promising future of mercury detoxification and pollution remediation utilizing cyanobacteria.

Key words:cyanobacteria;mercury;tolerance mechanism;accumulation