Remazol Red Dye Case Study
The release of dyes through contaminated water into the ecosystem from various industries like textile, leather, cosmetic, paper, pharmaceutical and food industries is not only a source of aesthetic pollution but also can cause human health disorders and adversely affects the aquatic life causing severe environmental problems worldwide. In view of increasing concern from perspective of environmental safety and health, physico-chemical and biological techniques are to be constantly explored for decolourization and degradation of dyes.
Remazol red RB dye was selected as model azo dye for the study. It is known to be toxicity, mutagenic and carcinogenic in nature because of the presence of the aromatic amine group (Zollinger, 2003; Jalandoni-Buan …show more content…
Under static conditions, decolourization of remazol red RB dye by bacterial isolates was more efficient than at shaking condition within 24 hours. In static condition transfer of oxygen is limited to the broth surface and the cell cultures will most likely sediment to the bottom of the flasks and become rapidly oxygen - depleted (Stolz, 2001; Chen, 2002).The reason for reduced decolourization at shaking condition could be due to the competition in oxidation of reduced electron carriers with either oxygen or azo groups as the electron acceptor (Mabrouk and Yusef, 2008; Dawkar et al., 2010). Microbial growth and bacterial decolourization are independent for decolourization of dyes as azoreductase is repressed under aerobic conditions (Chang et al., 2004).The data suggest that in static condition is more appropriate for the decolourization of the dye by the bacterium. Similar results were reported by bacterial strains are Shewanella putrefaciens AS96, Comamonas sp.UVS, Bacillus subtilis, Vibrio harveyi TEMS1 and Pseudomonas sp. SUK1. All these strains have shown promising results for dye degradation under static conditions (Khalid et al., 2008; Jadhav et al., 2008; Gurulakshmi et al., 2008; Ozdemir et al., 2008; Kalyani et al., 2009). Decolourization of azo dyes cannot take place in extreme anaerobic conditions that is under oxygen-free nitrogen sparging/gas flushing. This clearly implies that bacteria needs small amount of oxygen to maintain basic cellular activity for decolourization (Chen,
Remazol red RB dye was selected as model azo dye for the study. It is known to be toxicity, mutagenic and carcinogenic in nature because of the presence of the aromatic amine group (Zollinger, 2003; Jalandoni-Buan …show more content…
Under static conditions, decolourization of remazol red RB dye by bacterial isolates was more efficient than at shaking condition within 24 hours. In static condition transfer of oxygen is limited to the broth surface and the cell cultures will most likely sediment to the bottom of the flasks and become rapidly oxygen - depleted (Stolz, 2001; Chen, 2002).The reason for reduced decolourization at shaking condition could be due to the competition in oxidation of reduced electron carriers with either oxygen or azo groups as the electron acceptor (Mabrouk and Yusef, 2008; Dawkar et al., 2010). Microbial growth and bacterial decolourization are independent for decolourization of dyes as azoreductase is repressed under aerobic conditions (Chang et al., 2004).The data suggest that in static condition is more appropriate for the decolourization of the dye by the bacterium. Similar results were reported by bacterial strains are Shewanella putrefaciens AS96, Comamonas sp.UVS, Bacillus subtilis, Vibrio harveyi TEMS1 and Pseudomonas sp. SUK1. All these strains have shown promising results for dye degradation under static conditions (Khalid et al., 2008; Jadhav et al., 2008; Gurulakshmi et al., 2008; Ozdemir et al., 2008; Kalyani et al., 2009). Decolourization of azo dyes cannot take place in extreme anaerobic conditions that is under oxygen-free nitrogen sparging/gas flushing. This clearly implies that bacteria needs small amount of oxygen to maintain basic cellular activity for decolourization (Chen,