The outcome of competition between the two chrysomonads Ochromonas sp. and Poterioochromonas malhamensis depends on pH.

ABSTRACT: We investigated the effect of pH on the competition of two closely related chrysomonad species, Poterioochromonas malhamensis originating from circumneutral Lake Constance, and Ochromonas sp. isolated from a highly acidic mining lake in Austria (pH ∼2.6). We performed pairwise growth experiments between these two species at four different pH ranging from 2.5 to 7.0. Heterotrophic bacteria served as food for both flagellates. Results were compared to growth rates measured earlier in single species experiments over the same pH range. We tested the hypothesis that the acidotolerant species benefits from competitive release under conditions of acid stress. The neutrophilic strain numerically dominated over the acidotolerant strain at pH 7.0, but was the inferior competitor at pH 2.5. At pH 3.5

SUBMITTER: Moser M 

PROVIDER: S-EPMC3117142 | biostudies-literature | 2011 May

REPOSITORIES: biostudies-literature