Effect of Increased Temperature on Native and Alien Nuisance Cyanobacteria from Temperate Lakes: An Experimental Approach

Abstract

In response to global warming, an increase in cyanobacterial blooms is expected. In this work, the response of two native species of Planktothrix agardhii and Aphanizomenon gracile, as well as the response of two species alien to Europe—Chrysosporum bergii and Sphaerospermopsis aphanizomenoides—to gradual temperature increase was tested. The northernmost point of alien species distribution in the European continent was recorded. The tested strains of native species were favoured at 20–28 °C. Alien species acted differently along temperature gradient and their growth rate was higher than native species. Temperature range of optimal growth rate for S. aphanizomenoides was similar to native species, while C. bergii was favoured at 26–30 °C but sensitive at 18–20 °C. Under all tested temperatures, non-toxic strains of the native cyanobacteria species prevailed over the toxic ones. In P. agardhii, the decrease in concentration of microcystins and other oligopeptides with the increasing temperature was related to higher growth rate. However, changes in saxitoxin concentration in A. gracile under different temperatures were not detected. Accommodating climate change perspectives, the current work showed a high necessity of further studies of temperature effect on distribution and toxicity of both native and alien cyanobacterial species.

The Effects of Cyanobacterial Bloom Extracts on the Biomass, Chl-a, MC and Other Oligopeptides Contents in a Natural Planktothrix agardhii Population

“…Various environmental factors, such as water temperature, light and nutrient concentrations, influence MC synthesis indirectly through cellular growth [19,54]. In general, the toxicity of cyanobacterial blooms depends on the biomass of toxin producers [55,56] and the proportion of toxic genotypes in the population [45]. In our study, it has been confirmed that production of different MC isoforms, mainly derivatives of MC-RR and dmMC-LR, is a characteristic feature of Planktothrix subpopulations [17,56,57].…”

“…In general, the toxicity of cyanobacterial blooms depends on the biomass of toxin producers [55,56] and the proportion of toxic genotypes in the population [45]. In our study, it has been confirmed that production of different MC isoforms, mainly derivatives of MC-RR and dmMC-LR, is a characteristic feature of Planktothrix subpopulations [17,56,57]. We also found changes in the contribution of particular MC isoforms to the cellular content of MCs produced by P. agardhii exposed to different concentrations of the extracts.…”

“…The ecological role of cyanobacterial oligopeptides remains unknown and is widely discussed in different hypotheses [4,17,[24][25][26]. It was observed that strains without MC production contained other structurally related peptides instead [51,56,62]. For example, Sedmak et al [31] suggested that a possible role of cyanobacterial peptides in the natural environment is the control of cyanobacterial population density.…”

New insights into the distribution of alien cyanobacterium Chrysosporum bergii (Nostocales, Cyanobacteria)

“…Its invasive character in colonizing new areas may gain from competitive advantages including nitrogen fixation, formation of resting stages and ecological plasticity, similarly to other invasive Nostocales cyanobacteria (Sukenik et al 2012). We note that although the impacts of the higher water temperatures related to climate change is still somewhat uncertain, the influence of water and air temperature should not be neglected in future studies as temperature effect has been shown to be an important driver regulating expansion of invasive cyanobacteria (Savadova et al 2018).…”

“…We note that although the impacts of the higher water temperatures related to climate change is still somewhat uncertain, the influence of water and air temperature should not be neglected in future studies as temperature effect has been shown to be an important driver regulating expansion of invasive cyanobacteria (Savadova et al . ).…”