Decolorization of various dyes by thermophilic and mesophilic bacteria

In this study, decolorization of two different textile dyes, Foron Brown and Foron Black by thermophilic Anoxybacillus flavithermus and mesophilic Bacillus megaterium A1 was investigated under various incubation conditions. Therefore; 24-hour color removal studies were performed under various conditions for the thermophilic (40-55 ºC incubation temperatures, 50-250 ppm dye concentrations, 0-200 rpm shaking rates and pH 5.0-9.0) and the mesophilic (25-40 ºC incubation temperatures, 50-200 ppm dye concentrations, 0-200 rpm shaking rates and pH 5.0-9.0) bacterial isolates. According to this; the optimum incubation temperature value for A. flavithermus is 50 ºC, dye concentration is 200 ppm, shaking speed is 50 rpm and the medium pH is pH 5.0. On the other hand, the optimum incubation temperature, the dye concentration, the shaking speed and the medium pH are 30 ºC, 100 ppm, 150 rpm and pH 7.0, respectively for B. megaterium A1. Under the optimum conditions, while the decolorizations of Foron Brown and Foron Black by B. megaterium A1 were 79% and 87%, the decolorizations of Foron Brown and Foron Black by A. flavithermus were 72% and 83%, respectively. Moreover; the decolorization activities of these bacterial isolates against the mixture of Foron Brown and Foron Black and also the synthetic wastewaters were measured under the optimum conditions detected and high decolorization values were obtained after 24 hours of incubation.