Efficacy of Rhodococcus rhodochrous in Microbial Degradation of Toludine Dye

Abstract

An efficacy of Rhodococcus rhodochrous for the treatment of toludine red was investigated by using dye as sole carbon source. Optimization of various parameters such as pH, temperature, NaCl percentage (w/v) and dye concentration was studied by using one factor at a time method. Rhodococcus rhodochrous was capable of decolorizing Toluidine Red at a pH and temperature range of 6.5-9.5 and 25°C-40°C respectively and the best decolourization was achieved at 25ppm dye concentration, pH 6.5, temperature 35°C and 5% (w/v) NaCl. Optimized UV-Vis and HPLC analysis proposed that decolourization was occurred under biodegradation mechanism rather than bio sorption. GC/MS analysis was carried out to identify degradation products. Final compounds formed from dye degradation appeared at m/z 193 and m/z 77 which were identified as 2-(2-carboxy vinyl) benzoic acid and Benzene respectively. Related pathway for biodegradation mechanism was proposed. Findings revealed that salt tolerant bacteria, Rhodococcus rhodochrous was potential for removal of Toluidine Red at salty condition.