Isolation of dye degrading bacteria from soil and water contaminated with textile effluent

Azo compounds constitute the largest and the most diverse group of synthetic dyes and are widely used in a number of industries such as textile, food, cosmetics and paper printing. Most of the textile industries are using reactive azo dye because of the ease and cost effectiveness of their synthesis, their stability and the variety of colors available compared to the natural dyes. Majority of textile industries are releasing azo dyes into wastewater streams without any pretreatment that pollute water and soil environment. In this study, wastewater and soil samples were collected from contaminated sites around textile industries in Kelantan. 6 dye degrading bacterial isolates were successfully isolated on MSM supplemented with reactive azo dye agar plates. Two types of azo dyes was choosen in this research which are reactive black 5 and orange 16. These 6 isolates were tested for their potential to degrade reactive black 5 and reactive orange 16 by decolorization assay. Decolourization assays were conducted in two growth condition which are stationary and agitation. All the 6 isolated bacterial showed the best degradation activity under stationary condition which is more than 70% and 90% for reactive black 5 and orange 16 respectively. 16S rDNA gene was successfully amplified from both isolates.