Volatile organic compound emissions from Microcystis aeruginosa under different phosphorus sources and concentrations

In eutrophicated water, cyanobacteria massively grow and release an abundance of volatile organic compounds (VOCs) that contribute to the water odor. To uncover the effects of different phosphorus (P) nutrients on the formation of cyanobacteria VOCs and water odor, the cell growth and VOC emissions of Microcystis aeruginosa were investigated under different P nutrient conditions. Among K2HPO4, Na4P2O7, and (NaPO3)(6), K2HPO4 showed the largest increase in cell density, while a reduction in P concentration decreased the cell density. There were 26, 23 and 22 compounds in M. aeruginosa VOCs with K2HPO4, Na4P2O7 and (NaPO3)(6) as the sole P source, respectively, including sulfocompounds, terpenoids, benzenes, hydrocarbons, alcohols, aldehydes, and esters. Non-P markedly promoted the VOC emission, and six additional compounds were observed: alpha-pinene, 1-phenyl-1-butanone, 1H-1-ethylidene-indene, 2,6,10-trimethyl-tetradecane, 2-ethyl-hexanal, and acetic acid 2-ethylhexyl ester. It can be deduced that cyanobacteria release different VOC blends using various P forms in eutrophicated waters, and the reduction of P amount promotes VOC emission and increases the water odor.