Affiliations: Research Center for Lake Ecology and Environments,
Chinese Research Academy of Environmental Sciences, Beijing 100012, China | Department of Resources and Environments, Northwest
Sci-Tech University of Agriculture and Forestry, Shanxi 712100, China
Abstract: The growth processes of Microcystis aeruginosa (FACHB-41) in
simulated Taihu Lake water with different phosphorus concentrations were
investigated using laboratory microcosms. The algal biomass increased with the
increase of phosphorus concentration when it was lower than 0.445 mg/L, while
the dissolved oxygen (DO) and pH increased, dissolved inorganic nitrogen (DIN)
and light intensity underwater(I) decreased. Responding to the changes of the
"environmental factors", the cellular carbohydrate and its ratio to cellular
protein decreased generally as phosphorus increased. However, when phosphorus
concentration was higher than 1.645 mg/L, the biomass, the "environmental
factors", the cellular carbohydrate and its ratio to cellular protein did not
change likewise. Since the environmental factors and the physiological and
biochemical responses are important factors, the change of environmental
factors and cell physiology and biochemistry induced by phosphorus may become
the key factors that steer the growth and dominance of Microcystis under
certain conditions. To sum up, phosphorus not only stimulate the growth of
Microcystis directly by supplying nutrient element, but also has complex
interactions with other "environmental factors" and play important roles in the
growth processes of Microcystis.
