Microbial Decolourization of Cibacron Scarlet and Remazol Blue Dyes

Abstract

Eleven microorganisms that include six bacteria: Proteus mirabilis (LS), Proteus vulgaris (LE), Bacillus alvei (LS), Proteus mirabilis (AS), Bacillus polymyxa (AS), Bacillus alvei (AE), and five fungi: Penicillium antrovenetium (LS), Rhizopus oryzae (LEM), Penicillium funiculosum (LE), Rhizopus oryzae (LS) and Candida valida (LEM) were isolated from the effluent and soil samples collected from the premises of a textile manufacturing and local dyeing industries. The BOD and COD of the effluents collected from these industries were found to be relatively higher than the Nigeria Federal Environmental Protection Agency permissible level.

Increase in decolourization of Cibacron Scarlet was observed for all the isolates on day 5, seven of which showed decolourization greater than 50%. The highest decolourization of 85.7% was observed with P. mirabilis (AS) and R. oryzae (LS) had the lowest decolourization of 50.7%. B. alvei (LS) showed 74.8% decolourization of Remazol Blue on day 3, but decrease in the decolourization was observed for this organism on day 5. All the isolates showed decrease in the decolourization of Remazol blue at day 5 with the exception of three isolates; P. mirabilis (LS), B. polymyxa (AS) and R. oryzae (LS) with 46.3% and 64.1%, 54.1% and 67.8%, and 54.1% and 58.8%, respectively, on day 3 and day 5. Decolourization pH for Cibacron Scarlet by the bacterial isolates was slightly alkaline (8.5 – 8.8) and acidic (3.4 – 4.4) for the fungal isolates. Increase in bacterial count and fungal mycelia weight was observed as the decolourization progress. Thus, results obtained from this study revealed the decolourization potential of indigenous effluent and soil adapted microorganisms in decolourization of textile dyes.