title: Exploring the potential of anaerobic sulfate reduction process in treating sulfonated diazo dye: Microbial community analysis using bar-coded pyrosequencing.
abstract: Anaerobic decolorization and biotransformation of azo dye was investigated in a sulfate-reducing environment. Batch reactor studies were performed with mixed cultures of anaerobic sulfate-reducing bacteria (SRBs) enriched from anaerobic digester sludge. Complete sulfate and color removal were achieved in batch experiments with different initial dye concentrations (50-2500mg/L) and 1000mg/L of sulfate. Induction of various oxidoreductive enzyme activities such as phenol oxidase, veratryl alcohol oxidase, lignin peroxidase, and azo reductase was studied to understand their involvement in dye metabolism under anoxic environment. The degradation of Cotton Red B was confirmed using high-performance liquid chromatography and gas chromatography-mass spectroscopy. Sulfidogenic sludge demonstrated excellent dye degradation and mineralization ability, producing aniline and 1,4-diamino benzene as metabolites. A barcoded 16S rRNA gene-pyrosequencing approach was used to assess the bacterial diversity in the sludge culture and a phylogenetic tree was constructed for sulfate-reducing bacteria.
authors.affiliation: Qatar Environment and Energy Research Institute, Hamad Bin Khalifa University, Qatar Foundation, PO Box 5825, Doha, Qatar.
authors.forename: Kashif
authors.initials: K
authors.lastname: Rasool
authors.affiliation: Department of Environmental Engineering, Kyungpook National University, 80 Daehak-ro, Buk-gu, Daegu 41566, Republic of Korea.
authors.forename: Asif
authors.initials: A
authors.lastname: Shahzad
authors.affiliation: Department of Environmental Engineering, Kyungpook National University, 80 Daehak-ro, Buk-gu, Daegu 41566, Republic of Korea. Electronic address: daesung@knu.ac.kr.
authors.forename: Dae Sung
authors.initials: DS
authors.lastname: Lee
mesh_terms: D000693:Anaerobiosis; D000814:Aniline Compounds / Q000737:chemistry; D001419:Bacteria / Q000201:enzymology / Q000235:genetics / Q000378:metabolism; D019149:Bioreactors; D004396:Coloring Agents / Q000737:chemistry* / Q000378:metabolism; D003979:Diazonium Compounds / Q000737:chemistry* / Q000378:metabolism; D001330:Electronic Data Processing; D010084:Oxidation-Reduction; D016133:Polymerase Chain Reaction; D017423:Sequence Analysis, RNA; D013431:Sulfates / Q000737:chemistry*; D014865:Waste Disposal, Fluid / Q000379:methods*; D014871:Water Microbiology; D014874:Water Pollutants, Chemical / Q000737:chemistry* / Q000378:metabolism
chemical_list: D000814:Aniline Compounds; D004396:Coloring Agents; D003979:Diazonium Compounds; D013431:Sulfates; D014874:Water Pollutants, Chemical
keywords: 16S rRNA; Cotton Red B; Degradation; Pyrosequencing; Sulfate-reducing bacteria