Catherine Quiblier

TL;DR: It appeared that favorable conditions for Microcystis cell growth led to the selection, within the Micro Cystis population, of a non-microcystin-producing genotype, whereas potentially microcystIn- producing genotypes were dominant in this population before and after the bloom, when environmental conditions were less favorable for growth.

TL;DR: Applying quantitative real-time PCR to the mcyA and phycocyanin genes, it is found that only 54% of the variation in the MC concentrations measured in the lake can be explained by the dynamics of the density of cells with the MC producer genotype, suggesting this measurement is not a satisfactory method for use in monitoring programs intended to predict the toxic risk associated with cyanobacterial proliferation.

TL;DR: Environmental factors may have an indirect effect on the microcystin (MC) production rate, and on the selection of MC-producing and non-MC-producing strains, via their direct impact on both the cell growth rate and the cell densities in the cultures.

TL;DR: It is suggested that Microcystis colonies constitute a distinct habitat for bacteria living in freshwater ecosystems, and that direct and indirect interactions may occur between them inside these colonies.

TL;DR: Differences in the fitness of these two strains under optimum growth conditions were attributable to the cost to microcystin-producing cells of producing microCystins, and to the putative existence of cooperation processes involving direct interactions between these strains.