Dryland cyanobacterial exopolysaccharides show protection against acid deposition damage
Dryland cyanobacterial exopolysaccharides show protection against acid deposition damage
复制标题
旱地蓝藻胞外多糖显示出对酸沉积损伤的保护作用
DOI：
10.1007/s11356-019-05798-4
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发表时间：
2019-08-01
影响因子：
5.8
通讯作者：
Liu, Bin
中科院分区：
文献类型：
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作者：
Gao, Xiang;Liu, Li-Tao;Liu, Bin
土壤表层蓝藻是旱地生态系统的重要组成部分。它们建立的胞外多糖（EPS）基质在帮助细胞科普恶劣环境方面发挥着多种作用，并改善了土壤的理化性质。人为造成的大气氮或硫沉积已成为旱地的一个重要环境变化。沉积物中的酸性水分会被蓝藻EPS基质吸收，从而对细胞构成威胁。在这次交流中，我们评估了这种潜在的影响，在旱地蓝藻，发菜，这是一个代表性的富含多糖的物种，并显示出显着的抗干燥胁迫。发现EPS基质具有强的和弹性的pH缓冲特性，主要是多糖的作用，这可以保护细胞免受pH 4-6的酸损伤，pH 4-6是世界上雨水的一般酸度范围。与酸性水生环境不同，陆地干旱环境确保N。flagelliformesimpossible进行持久的严重酸化。因此，保护旱地蓝藻的EPS基质，将有助于维持其在大气酸污染下的生长和生态功能。
Soil surface-dwelling cyanobacteria constitute an important part of the dryland ecosystem. The exopolysaccharide (EPS) matrix they establish plays multiple roles in helping cells cope with harsh environments and also improves soil physicochemical properties. Anthropogenic atmospheric nitrogen or sulfur depositions have arisen as an important environmental change in drylands. The acid moisture derived from the depositions will be absorbed by cyanobacterial EPS matrix and thus may pose a threat to cells. In this communication, we evaluated this potential impact in a dryland cyanobacterium,Nostoc flagelliforme, which is a representative polysaccharide-rich species and shows remarkable resistance to desiccation stress. A strong and resilient pH buffering property was found for the EPS matrix, mainly of the polysaccharide’s role, and this could protect the cells from acid damage of pH 4–6, a general acidity range of rainwater in the world. Unlike in acid aquatic environments, terrestrial xeric environments ensureN. flagelliformeunlikely to undertake lasting severe acidification. Thus, protection of the EPS matrix for dryland cyanobacteria would be conducive to sustain their growth and ecological roles in face of atmospheric acid pollution.