Research Article
Degradation of the Azo Dye Reactive Red 195 by Paenibacillus spp. R2
Mohd Zaini Nawahwi1*, Zaharah Ibrahim2 and Adibah Yahya2 | |
1Department of Biology, Faculty of Applied Science, University Teknologi MARA, 72000 Kuala Pilah, Negeri Sembilan Malaysia | |
2Department of Industrial Biotechnology, Faculty of Bioscience and Bioengineering, Universiti Teknologi Malaysia, 81310 Skudai, Johor, Malaysia | |
Corresponding Author : | Mohd Zaini Nawahwi Department of Biology Universiti Teknologi MARA Kuala Pilah 72000 Negeri Sembilan, Malaysia Tel: 604832133 Fax: 604842449 E-mail: mohdzaini82@gmail.com |
Received: August 06, 2012; Accepted: November 11, 2012; Published: November 11, 2012 | |
Citation: Nawahwi MZ, Ibrahim Z, Yahya A (2013) Degradation of the Azo Dye Reactive Red 195 by Paenibacillus spp. R2. J Bioremed Biodeg 4:174. doi:10.4172/2155-6199.1000174 | |
Copyright: © 2013 Nawahwi MZ, et al. This is an open-a ccess article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. | |
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Abstract
Azo dyes are a widespread class of poorly biodegradable industrial pollutants. In anaerobic environments, azo bonds are reductively cleaved yielding carcinogenic aromatic amines, many of which are assumed to resist further metabolism by anaerobes bacteria. The latter compounds generally require aerobic conditions for their degradation. A reactive group of azo dye called SFRed (C.I: Reactive Red 195) was found to be degraded using Gram negative, coccobacillus, facultative anaerobe bacteria, Paenibacillus sp. R2 to α-ketoglutaric acid with transient accumulation of 4-aminobenzenesulphonic acid (sulphanilic acid), 4-amino, 3-hydronapthalenesulphonic acid and 4-amino, 5-hydronapthalene 2,7 disulphonic acid as a degradation intermediate in anaerobic facultative batch culture. Colour and total organic carbon (TOC) was successfully removed more than 95% and up to 50% respectively. There is no significant correlation between pH and oxygen depletion since there is slightly change in pH was observed (pH from 7.21 to 7.25) though the anaerobiosis was found developed throughout the experiment (redox potential from 0.7 to 1.6 mV). The anaerobic metabolism of glucose as co-metabolite also shown to provide the electrons required for the
initial reductive cleavage of the azo group. This finding suggest that it is possible to mineralize the azo dye in the environment; thereby, avoiding accumulation of toxic intermediates in the water.