US EPA

7458557 

Journal Article 

铜绿微囊藻生长代谢的密度依赖性特征及分子机制 

Yan, G; Fu, L; Xie, Y; Ming, H; Zhou, D 

2020 

Yes 

Huanjing Kexue Xuebao / Acta Scientiae Circumstantiae
ISSN: 0253-2468 

Science Press 

40 

10 

3757-3763 

Chinese 

10.13671/j.hjkxxb.2020.0424 

Cyanobacteria bloom is a common water environment problem in freshwater lakes. Most of the mechanisms of bloom formation focus on external environmental factors but ignore the key regulatory role of algae itself and its population. In this study, the initial cell density serve as a single variable, the cell growth, nutrient utilization, chlorophyll, microcystin and extracellular secretion of cyanobacteria under different initial cell densities were investigated over time. It was found that the initial cell density affected the environmental adaptability and the cell growth. When the initial cell density was higher than 1×106 cell•mL-1, the adaptive phase was disappeared. The initial cell density increased from 1×105 cell•mL-1 to 1×107 cell•mL-1, the maximum cell density increased by 68% and the growth rate increased by 21%. The variation tendency of chlorophyll were consistent with the cell growth results. The extracellular secretion increased gradually with the increase of initial cell density, which was conducive to the aggregation of cyanobacteria cells and biofilm formation. When the initial cell density was 1×105 cell•mL-1, the secretion of single cell microcystin was higher to improve the environmental adaptability. The high initial cell density(1×107 cell•mL-1) promoted the growth and proliferation of Microcystis aeruginosa by up-regulating pyruvate metabolism and carbon metabolism. Therefore, cell density is an important factor for the growth and metabolism of Microcystis aeruginosa and it maybe play a crucial role in the cyanobacterial blooms. The prevention and control of blooms should be started at the initial stage with low cell density. © 2020, Science Press. All right reserved. 

Blooms; Cell density; Microcystin; Microcystis aeruginosa; Physiological feature