Response of the cellular components to environmental factors indicates limiting factors of Microcystis in Lake Taihu
Studying the influence of environmental factors on the growth and physiological state of cyanobacteria is an important basis for understanding the formation of cyanobacteria content. This study selected Microcystis aeruginosa as an example, using algal pigment and fatty acid composition to reflect the physiological state of Microcystis, and analyzed the effects of environmental changes on the basic physiological indicators of Microcystis cells. The results showed that an increase in light strength caused the ratio of Chlorophyll a to proteins to decrease and then increase, but has little effect on fatty acids. Increasing the temperature caused Microcystis cells to increase photosynthesis pigments and polysaccharides to proteins ratio and caused fatty acid Palmitic acid C16:0 to decrease and then increase, as opposed to linoleic acid gamma-C18:3. When the N:P ratio was 9.4, an increase in N concentration caused the Chlorophyll a to PR ratio to increase, and PS, TOC, beta-carotene and zeaxanthin to PR ratio decrease. At P = 1.7 mg L-1, an increase N:P ratio promoted photosynthetic pigmentation of algae, which increased the PS to PR ratio. During autumn and winter, the fatty acids of Lake Taihu Microcystis cells were mostly C16:0 and C18:1, of which C16:0 changed most significantly during the winter period, showing a trend of decreasing first and then increasing later. Cluster analysis and the comparison of laboratory data found that the limiting factors affecting the growth of Lake Taihu Microcystis during this period were mainly temperature and nitrogen concentrations.
（来源: AQUATIC ECOLOGY出版年: 2022,DOI: 10.1007/s10452-022-09997-z）