微囊藻具有在世界各地的湖泊和水库中形成菌落和水华的能力,对水生生态系统造成重大的生态挑战。然而,对控制微囊藻竞争优势的物理化学表面性质的决定因素知之甚少。这里,韦森贝微囊藻和铜绿微囊藻的理化表面特性,包括比表面积(SSA),疏水性,zeta电位,和功能组进行了调查。此外,分析胞外多糖(EPS)。实验室培养的微囊藻表现出亲水性,负zeta电位和带负电荷。此外,这些特性与培养阶段之间没有显着关系。wesenbergii微囊藻表现出低的内聚自由能,高表面自由能,高增长率,对数期EPS含量较高。另一方面,铜绿假单胞菌显示出较低的内聚自由能,高表面自由能,高EPS含量,在稳定期和高增长率。这些特征有助于它们各自的竞争优势。此外,研究了EPS与表面性能的关系。EPS的多糖成分主要影响微囊藻的SSA和总表面能。同样,EPS的蛋白质成分影响疏水性和表面张力。多糖组合物,包括葡萄糖醛酸,木糖,和果糖,主要影响表面性质。此外,亲水基团如O-H和P-O-P在决定微囊藻的疏水性中起着至关重要的作用。这项研究阐明了EPS影响SSA,疏水性,微囊藻细胞的表面自由能,进而影响微囊藻的形成和集合。
Microcystis possesses the capacity to form colonies and blooms in lakes and reservoirs worldwide, causing significant ecological challenges in aquatic ecosystems. However, little is known about the determining factors of physico-chemical surface properties that govern the competitive advantage of Microcystis. Here, The physico-chemical surface properties of Microcystis wesenbergii and Microcystis aeruginosa, including specific surface area (SSA), hydrophobicity, zeta potential, and functional groups were investigated. Additionally, the extracellular polysaccharide (EPS) were analyzed. Laboratory-cultured Microcystis exhibited hydrophilic, a negative zeta potential and negatively charged. Furthermore, no significant relationship was shown between these properties and the cultivation stage. Microcystis wesenbergii exhibited low free energy of cohesion, high surface free energy, high growth rate, and high EPS content during the logarithmic phase. On the other hand, M. aeruginosa displayed lower free energy of cohesion, high surface free energy, high EPS content, and high growth rate during the stationary phase. These characteristics contribute to their respective competitive advantage. Furthermore, the relationship between EPS and surface properties was investigated. The polysaccharide component of EPS primarily influenced the SSA and total surface energy of Microcystis. Likewise, the protein component of EPS influenced hydrophobicity and surface tension. The polysaccharide composition, including glucuronic acid, xylose, and fructose, mainly influenced surface properties. Additionally, hydrophilic groups such as O-H and P-O-P played a crucial role in determining hydrophobicity in Microcystis. This study elucidates that EPS influenced the SSA, hydrophobicity, and surface free energy of Microcystis cells, which in turn impact the formation of Microcystis blooms and the collection.