Joint effects of five environmental factors on the growth of cyanobacterium Microcystis aeruginosa

Abstract

Abstract In many lakes and reservoirs, Microcystis aeruginosa is one of the dominant bloom species. Five environmental factors, including nutrients and physical factors, were selected to evaluate their effects and interactions on the growth of M. aeruginosa (FACHB-905) by joint analysis in a laboratory batch culture. The results indicated that all five factors affected the growth rate alone or in combination, and that their interactions were complex. This cyanobacterium strain preferred higher water temperature and alkaline conditions, while not requiring high illumination or high concentrations of nitrogen and phosphorus. Owing to these features the bloom of this cyanobacterium appears easily in nature. The form of nitrogen (nitrate or ammonium) also affected the assessment of M. aeruginosa bloom. The possibility of M. aeruginosa bloom would still exist even if the phosphorus concentration in the water column was very low. The result provided a good basis for the analysis and prediction of M. aeruginosa blooms in terms of environmental assessment, because the joint analysis of multiple factors would offer more valuable information than a univariate analysis. This article has been made Open Access thanks to the kind support of CAWQ/ACQE (https://www.cawq.ca).