Kinetic of Azo Dyes Decolourization by Enterobacteriaceae Species in the Intact Cell Assay System

The method “Intact cell assay” was adopted to assess the influencing factors on the process of decolourization ability of the enterobacteriaceaea specie isolates under predisposed environment. Taken into account several ingredient are added individually as well in combinations in the assay reaction. Values of dye decolourized in μg ml^-1 with Multi vitanmins solution (MVS) with glucose 42.53; MVS 36.00; Riboflavin (RF) 39.00; Yeast extract 36.00 and B- complex 23.00 from the initial dye of 46.00μg ml^-1 were observed , where as glucose, Ascorbic acid, Cysteine, Cetyl-trimethyl-ammonium bromide (CTAB), Sodium molybdate, Biotin, KNO₃, NaNO₂, folic acid and 1-amino-2- naphtho-4-sulfonic acid (ANSA) does not shows influence on to the process, but, some of them showed inhibitory effect toward the decolourization. It was observed that the riboflavin addition at 19.95 n moles ml^-1 in the reaction mixture, rate of decolourization was suddenly change from 0.019 ΔA/minutes to 0.20 ΔA/minutes, which is extremely high by 10 fold fast and subsequently remains faster i.e 0.2 ΔA/minutes without further additional RF in the same assay mixture. Rate of decolourization with different concentrations of riboflavin i.e. 13.0 n moles ml^-1 to 59.9 n moles ml^-1 showed second order kinetic. This indicates that the minimum amount of RF is essential to trigger the process of decolourization by the intact cells under the assay condition. While five different azo dyes were subjected, showed diverse behavior on to the rate of decolourization. Results of entire study incite on role of riboflavin could to a certain extent act as a redox mediator in the reaction(s) process and electron mediator between intracellular pool to the dye available at periplasmic redox sink