This study focused on the isolation and identification of potential dye degrading bacteria from tannery effluent. The ability of these bacteria to decolorize three leather dyes viz. black, brown and red dyes were also examined. Based on morphological, cultural, physiological and biochemical properties, isolates were provisionally identified up to species level as Pseudomonas putida (RS1A), Bacillus sphaericus (RS1B), Bacillus brevis (RS1C), Pseudomonas stutzeri (RS1D), Alcaligenes eutrophus (RS1E), Listeria denitrificans (RS2A), Listeria grayi (RS2B), Listeria murrayi (RS2C), Bacillus coagulans (RS2D) and Listeria monocytogenes (RS2E). In dye decolorization study, Pseudomonas stutzeri (RS1D) completely decolorized 1000 ppm black dye within 8 days. Listeria monocytogenes (RS2E) was found most potential strain capable of completely decolorizing up to 1000 ppm of black dye and same conc. of brown dye moderately during 9 and 10 days of incubation, respectively. In contrast, weak decolorization of red dye was observed by Bacillus brevis (RS1C), Pseudomonas stutzeri (RS1D) and Listeria monocytogenes (RS2E) at low conc. e.g., 100-200 ppm. Bacillus coagulans (RS2D) was found least potential in decolorizing all dyes. Irrespective of dyes, Listeria monocytogenes (RS2E) was the most potent and its potentiality can be exploited to clean up the environment.
Published Date: 2019-04-08; Received Date: 2019-03-23