DEGRADATIVE DETOXIFICATION OF REACTIVE RED 195 BY BACTERIAL ISOLATES

Abstract

Synthetic dyes are widely used in textile, cosmetic, printing, drug and food processing industries. The generation and
disposal of insufficiently treated coloured wastewater is environmentally hazardous. Such wastewater leads to dye
contamination of the environment such as soil and natural water bodies. Biological treatment methods are cheap and
offer best alternative as compared to physico-chemical methods. Bacterial decolourization and degradation is ecofriendly
and cost competitive. In the present study, Reactive Red 195 was used as a model reactive azo dye. Bacteria selected for
the study were identified as Enterococcus faecalis, Georgenia sp., Bacillus cereus and Pseudomonas aeruginosa. The efficiency of
the decolourization of the dye by the isolates was compared with a known dye degrader Micrococcus glutamicus NCIM 2168.
Effect of various physico chemical factors was studied to detect optima for pH, temperature and dye concentration.
Degradation was confirmed by Uv-Vis absorption, TLC, HPLC and GC-MS studies. Enzymes involved in degradation
studies were found to be oxidoreductases. Toxicity assay showed nontoxic nature of the degradation products. Hence the
isolates having ability to degrade and detoxify the dye can be used for treatment of coloured wastewater.