Effects of Varying Temperature on the Growth Rate of Toxic and Non-Toxic Strains of <i>Microcystis aeruginosa</i>

Abstract

Cyanobacterial bloom, also called blue-green algae, all over the world is generating great concern due to the effect of temperature resulting from global warming. Microcystis aeruginosa is well known to be the major causative agent of algal bloom. However, there is a need for more critical detection to the relationship between temperature and the growth rate of Microcystic aeruginosa. In the present study, we cultivated the batch culture of Microcystis aeruginosa (Toxic and Non-toxic strain) at five different temperatures 5°C, 10°C, 22°C, 27°C, and 38°C to measure its specific growth rate, pigment contents and cell concentration at each temperature. Our findings indicate that non-toxic strains had higher growth rate at high temperature than the toxic strains, particularly at 22°C. Also, a minimal difference was noticed with the chlorophyll a, carotenoid contents of both strains at varying temperature. The above results indicate the significance of temperature in respect to the two strains of M. aeruginosa and could constitute a promising tool in the prediction of algal bloom.