Aquatic Ecology

, Volume 41, Issue 4, pp 525–533

Influence of N/P ratio on competitive abilities for nitrogen and phosphorus by Microcystis aeruginosa and Aulacoseira distans

  • Marcelo Manzi Marinho
  • Sandra Maria Feliciano de Oliveira e Azevedo
Article

DOI: 10.1007/s10452-007-9118-y

Cite this article as:
Marinho, M.M. & de Oliveira e Azevedo, S.M.F. Aquat Ecol (2007) 41: 525. doi:10.1007/s10452-007-9118-y

Abstract

Microcystis aeruginosa and Aulacoseira distans strains were grown in batch cultures to investigate the consequences of N/P ratio on the growth of these species and on their abilities to take up nitrogen and phosphorus. N/P ratio did not influence the growth rates, which were similar under all the experimental conditions. However, exponential growth lasted longer in Microcystis than in Aulacoseira, especially under low N/P ratio conditions. Distinct patterns of nutrient uptake for Aulacoseira and Microcystis were observed. N-uptake was higher in Microcystis, but not influenced by N/P ratio. However, the amount absorbed was proportional to the concentration in the culture medium for both strains studied. Although Microcystis showed lower uptake of N per biomass unit, a greater yield of Microcystis growth relative to the diatom was observed. This could have resulted from its ability to produce biomass using less nitrogen per unit of biomass. A variation of N/P ratio in the culture medium during the growth of both species was observed. This owed to the uptake of nutrients, with Microcystis showing greater potential than Aulacoseira to influence the N/P ratio. Thus, in contrast to what has been stated in the literature, our results indicated that a low N/P ratio could be a consequence of the capacities and rates of cyanobacterial uptake of nitrogen and phosphorus.

Keywords

CompetitionCyanobacteriaDiatomsGrowthN and P uptakeBatch cultures

Copyright information

© Springer Science+Business Media B.V. 2007

Authors and Affiliations

  • Marcelo Manzi Marinho
    • 1
  • Sandra Maria Feliciano de Oliveira e Azevedo
    • 2
  1. 1.Laboratório de Ecologia e Taxonomia de Algas – DBV/IBRAGUniversidade do Estado do Rio de JaneiroRio de JaneiroBrasil
  2. 2.Laboratório de Ecofisiologia e Toxicologia de Cianobactérias (LETC), Instituto de Biofísica Carlos Chagas FilhoUniversidade Federal do Rio de JaneiroRio de JaneiroBrasil