蓝细菌对汞耐受机制的研究进展

Advances in the mercury tolerance mechanisms of cyanobacteria

摘要:

蓝细菌对不同形态的汞具有很强的耐受和富集能力，能够改变环境中的汞浓度，影响汞的生物地球化学循环。同时，蓝细菌是生态系统中重要的初级生产者，经过蓝细菌富集的汞更容易进入食物链，影响人类健康。本文系统总结了蓝细菌对汞的耐受机制，主要包括：(1)在细胞壁外合成胶质鞘隔离汞；(2)通过与自身化合物结合钝化汞的毒性；(3)利用自身抗氧化机制修复汞对细胞的损伤；(4)利用自身酶转化汞的形态降低毒性；(5)与抗汞细菌共生抵御汞。基于此，本文展望了蓝细菌汞耐受机制的进一步研究方向，以及利用蓝细菌进行汞解毒和污染修复的前景。

关键词:蓝细菌;汞;耐受机制;富集

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