Blue-green Algal Ammonia Uptake in Hypertrophic Prairie Lakes

Abstract

Within 24 h of an increase in lake NH4+ concentration, NH4+ uptake by Aphanizomenon flos-aquae and Microcystis aeruginosa increases much beyond the capacity predicted by Michaelis-Menten kinetic studies. In hypertrophic lakes this response enables these blue-green algae to optimize NH3 uptake during large oscillations of NH4+ concentration, to aid them in competing with other algae and to conserve NH4+ within the ecosystem. N limitation in the hypertrophic prairie lakes is a rare event.