title: Plasticity of Total and Intracellular Phosphorus Quotas in Microcystis aeruginosa Cultures and Lake Erie Algal Assemblages.
abstract: Blooms of the potentially toxic cyanobacterium Microcystis are common events globally, and as a result significant resources continue to be dedicated to monitoring and controlling these events. Recent studies have shown that a significant proportion of total cell-associated phosphorus (P) in marine phytoplankton can be surface adsorbed; as a result studies completed to date do not accurately report the P demands of these organisms. In this study we measure the total cell-associated and intracellular P as well as growth rates of two toxic strains of Microcystis aeruginosa Kütz grown under a range of P concentrations. The results show that the intracellular P pool in Microcystis represents a percentage of total cell-associated P (50-90%) similar to what has been reported for actively growing algae in marine systems. Intracellular P concentrations (39-147 fg cell(-1)) generally increased with increasing P concentrations in the growth medium, but growth rate and the ratio of total cell-associated to intracellular P remained generally stable. Intracellular P quotas and growth rates in cells grown under the different P treatments illustrate the ability of this organism to successfully respond to changes in ambient P loads, and thus have implications for ecosystem scale productivity models employing P concentrations to predict algal bloom events.
authors.affiliation: Department of Microbiology, University of Tennessee Knoxville, TN, USA.
authors.forename: Matthew A
authors.initials: MA
authors.lastname: Saxton
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Arnold
authors.forename: Richard A
authors.initials: RA
authors.lastname: Bourbonniere
authors.forename: Robert Michael L
authors.initials: RM
authors.lastname: McKay
authors.forename: Steven W
authors.initials: SW
authors.lastname: Wilhelm