Thermal-dependent growth characteristics for Cylindrospermopsis raciborskii (Cyanoprokaryota) at different light availabilities: methodological considerations

Abstract

Cylindrospermopsis raciborskii is one of the most common species of cyanobacteria that can cause nuisance blooms in tropical and subtropical waters. The spatial distribution of this species has become more widespread in temperate regions during the last decade. Sixty combinations of the interaction of light and temperature conditions were examined in this study to elucidate the growth dynamic of C. raciborskii ACT 9502 isolated from a temperate shallow lake (Lake Balaton, Hungary). The maximum growth rate of this strain was observed at 32.8 °C with 164 µmol m−2 s−1 of irradiance. C. raciborskii ACT 9502 was able to grow at both low and high temperatures if the irradiance was low, but could not tolerate the high irradiance at low temperatures. Low-temperature-induced photoinhibition was observed on higher irradiances with increasing temperature. Results here provide indirect evidence that with global warming, adaptation and high tolerance to a wide range of environmental factors, a harmful cyanobacteria can successfully expand to higher latitudes. The gradient experiment also demonstrated that the determination of temperature cardinals of growth and category of high light or shading tolerance significantly depend on the environmental irradiance and temperature. These are important parameters that must be considered when comparing global determinations of growth parameters of this invasive species.