Large Microcystis colonies can lead to the rapid formation of surface accumulations, which are a globally significant environmental issue. Laboratory studies have shown that Ca²⁺ can quickly promote non-classical Microcystis colony formation via cell-adhesion, but our knowledge of the changes in the morphology of these colonies during subsequent long-term culture with Ca²⁺ is limited. In this study, a 72-day cultivation experiment was conducted to determine the long-term effects of Ca²⁺ on Microcystis colony formation. Laboratory results indicate that Ca²⁺ causes Microcystis to rapidly aggregate and form a colony through cell adhesion, then colony formation by cell-adhesion lost dominance, owing to the decrease in Ca²⁺ concentrations caused by precipitation/complexation. Although the initial colony morphology by cell adhesion is sparse, the newly divided cells, without separating from the mother cells, constantly fill the gaps in the original colony at Ca²⁺ concentrations >40 mg L⁻¹ for a long time, which creates colonies on day 72 with a morphology similar to that of M. ichthyoblabe in Lake Taihu. If the Ca²⁺ levels in Lake Taihu continue to increase, Microcystis growth rate will decrease only slightly, while the colony proportion of total biovolume and biomass will increase. Moreover, higher Ca²⁺ concentrations do not affect microcystin content, but promote the content of bound extracellular polysaccharides (bEPS), enabling formation of larger colonies, which may promote Microcystis surface accumulation.

大的微囊藻菌落会导致表面积累的迅速形成，这是全球性的重大环境问题。实验室研究表明，Ca ²⁺可以通过细胞粘附迅速促进非经典微囊藻菌落的形成，但是我们对随后的Ca ²⁺长期培养过程中这些菌落形态变化的了解有限。在这项研究中，进行了72天的培养实验，以确定Ca ²⁺对微囊藻菌落形成的长期影响。实验室结果表明Ca ²⁺引起微囊藻通过细胞粘附迅速聚集并形成菌落，然后由于沉淀/复合作用引起的Ca ²⁺浓度降低，通过细胞粘附形成的菌落失去了优势。尽管最初通过细胞粘附形成的菌落形态很稀疏，但新分裂的细胞没有与母细胞分离，而是在Ca ²⁺浓度> 40 mg L ^-1的情况下长时间不断填充原始菌落的间隙，从而形成了菌落在第72天，其形态类似于太湖中的ichichyoblabe菌。如果太湖中的Ca ²⁺含量继续增加，则微囊藻生长速度只会略有下降，而总生物量和生物量的菌落比例会增加。此外，较高的Ca ²⁺浓度不会影响微囊藻毒素的含量，但会提高结合的细胞外多糖（bEPS）的含量，从而形成较大的菌落，从而可能促进微囊藻的表面积累。