Study on destruction of extracted toxins from isolated Cyanobacteria using titanium dioxide

Abstract

Cyanobacteria are major group of microorganism with capability to produce different types of toxin. Indeed, anthropogenic eutrophication of surface water is the main reason for acceleration of their growth and ecological problems. Therefore, the present study tried to isolate toxic cyanobacteria from Kor River, Fars province. For this purpose, 18 water samples were collected from three sampling stations of Kor River, namely: Rah-Ahan Bridge, Esfandaran and Khan Bridge stations. The samples were serially diluted and cultivated on BG11 media under illumination of 1500 to 2000 lux with 12/12 h light/dark regime at 28 ± 2 °C. Then the colonies were purified and molecularly identified using three sets of primers. The toxins were extracted according to Anjos protocols and confirmed by HPLC. Finally, effect of titanium dioxide under ultraviolet lights with a wavelength of 450-330 nm for half an hour evaluated. The results obtained from this study indicated that 4 different isolates were detected from sampling sites. The isolates had capability to produce toxins ( Microcystin, Cylindrospermopsin) and their presence were confirmed by HPLC. In addition, the toxins were affected by titanium dioxide. Although the titanium dioxide has detoxifying ability, evaluation of different concentration of titanium dioxide on different types of toxins is suggesting.