环境因子介导细胞表面特性解析铜绿微囊藻群体形成机制

Deciphering the mechanism of Microcystis aeruginosa colony formation mediated by environmental factors via cell surface property analysis

摘要

群体的形成对于微囊藻种群优势维持和水华暴发至关重要.以铜绿微囊藻为研究对象,探究其在不同Ca²⁺、N、P质量浓度以及温度和光照强度下的群体形成情况及机理.结果表明,在高Ca²⁺、低N、P质量浓度和高光强条件下均出现了群体,D₅₀最大分别为37.45、38.22、23.15和36.78μm.相比各对照组,高Ca²⁺、低N、低P、强光和低温条件使结合型胞外聚合物(bound extracellular polymeric substances,B-EPS)含量最大分别升高了54.77%、50.33%、33.06%、59.80%和67.87%;Zeta电位最高分别升高47.65%、24.79%、27.61%、8.11%、43.49%.表明这些环境因子可能通过刺激铜绿微囊藻分泌更多的B-EPS、升高Zeta电位等途径改变细胞表面特性,降低细胞间排斥作用来促进铜绿微囊藻聚集.

Abstract

Colony formation is crucial for the dominance of Microcystis species and blooms. The research investigated the impact of Ca ²⁺ concentrations, nitrogen (N) and phosphorus (P) concentrations as well as temperatures and light intensities on M. aeruginosa colony formation and elucidated the underlying mechanisms. The results demonstrated that Microcystis colonies appeared under high Ca ²⁺ concentration, low N and P concentration, high light intensity and low temperature conditions, with maximum D ₅₀ values of 37.45, 38.22, 23.15, and 36.78 μm, respectively. Compared to the control groups, high Ca ²⁺, low N and P, high light intensity, and low-temperature conditions increased the content of bound extracellular polymeric substances (B-EPS) by 54.77%, 50.33%, 33.06%, 59.80%, and 67.87%, respectively, and elevated the Zeta potentials by 47.65%, 24.79%, 27.61%, 8.11%, and 43.49%, respectively. These findings suggest that these environmental factors may promote the aggregation of M. aeruginosa by stimulating the secretion of B-EPS, increasing the surface Zeta potentials, and altering cell surface properties, thereby reducing intercellular repulsion.

关键词

蓝藻水华 / 铜绿微囊藻 / 群体 / 环境因子 / 聚集机制

Key words

cyanobacterial bloom / Microcystis aeruginosa / colony / environmental factors / aggregation mechanisms

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基金资助

国家自然科学基金(42207086)