Biodegradation of Malachite Green by Klebsiella Terrigenaptcc 1650: The Critical Parameters Were Optimized Using Taguchi Optimization Method

Abstract

In the work ahead, the microbial degradation of Malachite Green (MG) was investigated by the bacterium Klebsiella. At first, the Taguchi Optimizing Method (TOM) was used to optimize the experimental conditions. 16 introduced states were tested by the L-16 array type of the software and each case was repeated three times for calculating signal/noise (S/N) ratio. Based on S/N ratio, it was found that, the best experimental conditions will be at the dye concentration of (25 ppm), temperature (30°C), pH (~6), carbon source (Lactose) and nitrogen source (Ammonium nitrate). After reviewing the obtained results of Taguchi software, were found that, initial dye concentration and nitrogen source are most and less effective in the MG degradation experiments respectively. For experimental study, the MSM (Mineral Salt Medium) with phosphate buffers (for pH of 6, 6.6 and 7), Tris tampons (for pH of 6.7, 8 and 4.8) and acetic acid/sodium acetate tampons (for pH of 5 and 6.5) were used. For chemical analysis, dichloromethane was used as organic solvent. Eventually, UV-Visible absorption spectrum, HPLC and FTIR analysis confirmed completely degradation of MG by the bacterium Klebsiella.