Initial growth phases of two bloom-forming cyanobacteria (Cylindrospermopsis raciborskii and Planktothrix agardhii) in monocultures and mixed cultures depending on light and nutrient conditions

摘要: Proliferations of cyanobacteria have detrimental effects on ecosystem functioning, and the global freshwater food chain. Many studies focused "in situ" dynamics bloom-forming cyanobacteria, including Cylindrospermopsis raciborskii Planktothrix agardhii. Few used experi- mental assays to explore fast-growing ability naturally co-occurring species. Here we investigated growth these species when exposed separately (i.e., in monocultures) a range light nutrient con- ditions, plus their interactive performances mixed cultures short-time experiment (6 days). The use microplates made it possible carry out multiple measurements in-vivo fluorescence (IVF), monitor species-dependent biovolumes. No allelopathic effect was significantly observed for any target species, while lower rates were obtained cultures, which may reflect other interference inter- actions between We showed that grew faster with low intensity high nu- trient concentrations, drastically inhibited by nitrogen deprivation, contrast Cylindrospermopsis. However, outgrew at NH4 suggesting this be serious competitor native many water systems.