Isolation and characterization of a Methyl Red-Degrading Pseudomonas sp. from Contaminated Soil
DOI:
https://doi.org/10.54987/jemat.v13i1.1107Keywords:
Pseudomonas sp. Aft-12, Methyl red decolorization, Azoreductase activity, Textile wastewater bioremediation, Minimal salt mediumAbstract
Microbial-based bioremediation is a greener dye removal method than physicochemical methods like coagulation-flocculation, adsorption, membrane filtration, and advanced oxidation. In this study, we isolated and characterized a methyl red-degrading Pseudomonas sp. from contaminated soil, examining its growth and degradation under different environmental conditions. The bacterium, tentatively designated as Pseudomonas sp. strain Aft-12 demonstrated strong methyl red decolorization capacity. Time-course growth analysis in minimal salt medium supplemented with 200 mg/L methyl red, glucose as a carbon source, and ammonium sulphate as a nitrogen source revealed a minimal lag phase (~12 h), followed by rapid exponential growth and decolorization, reaching completion by 72 h. Strain Aft-12 performed effectively across a range of conditions, showing optimal growth between pH 6.5 and 7.0 and between 30 and 35 °C. Growth was optimal at dye concentrations of between 200 and 250 mg/L. Co-substrate screening revealed that glucose and sucrose significantly enhanced biomass, although Aft-12 maintained activity without supplementation. Azoreductase activity peaked at 1 µmol/min/mg protein after 48 h, supporting enzymatic decolorization via reductive cleavage. These characteristics make this bacterium a promising candidate for sustainable bioremediation of azo dye-laden effluents.
References
Gupte S, Keharia H, Gupte A. Toxicity analysis of azo Red BS and Methyl Red dye solutions on earthworm (Pheretima phosthuma), micro-organisms, and plants. Desalination Water Treat. 2013;51(22-24):4556-65.
Chung KT, Fulk GE, Andrews AW. Mutagenicity testing of some commonly used dyes. Appl Environ Microbiol. 1981 Oct;42(4):641-8.
IARC. Some Aromatic Amines, Organic Dyes, and Related Exposures. In: IARC monographs on the evaluation of carcinogenic risks to humans [Internet]. 2010 [cited 2025 Aug 9]. Available from: http://publications.iarc.who.int/Book-And-Report-Series/Iarc-Monographs-On-The-Identification-Of-Carcinogenic-Hazards-To-Humans/Some-Aromatic-Amines-Organic-Dyes-And-Related-Exposures-2010
Adedayo O, Javadpour S, Taylor C, Anderson WA, Moo-Young M. Decolourization and detoxification of Methyl Red by aerobic bacteria from a wastewater treatment plant. World J Microbiol Biotechnol. 2004;20(6):545-50.
Wong PK, Yuen PY. Decolorization and biodegradation of methyl red by Klebsiella pneumoniae RS-13. Water Res. 1996;30(7):1736-44.
Feng J, Heinze TM, Xu H, Cerniglia CE, Chen H. Evidence for significantly enhancing reduction of Azo dyes in Escherichia coli by expressed cytoplasmic azoreductase (AzoA) of Enterococcus faecalis. Protein Pept Lett. 2010;17(5):578-84.
Ayed L, Mahdhi A, Cheref A, Bakhrouf A. Decolorization and degradation of azo dye Methyl Red by an isolated Sphingomonas paucimobilis: Biotoxicity and metabolites characterization. Desalination. 2011 July 1;274(1):272-7.
Sugiura W, Miyashita T, Yokoyama T, Arai M. Isolation of azo-dye-degrading microorganisms and their application to white discharge printing of fabric. J Biosci Bioeng. 1999;88(5):577-81.
Jadhav SU, Kalme SD, Govindwar SP. Biodegradation of Methyl red by Galactomyces geotrichum MTCC 1360. Int Biodeterior Biodegrad. 2008 Sept 1;62(2):135-42.
Galai S, Limam F, Marzouki MN. A new Stenotrophomonas maltophilia strain producing laccase. use in decolorization of synthetics dyes. Appl Biochem Biotechnol. 2009;158(2):416-31.
Kalyani DC, Telke AA, Dhanve RS, Jadhav JP. Ecofriendly biodegradation and detoxification of Reactive Red 2 textile dye by newly isolated Pseudomonas sp. SUK1. J Hazard Mater. 2009 Apr 30;163(2):735-42.
Abd Shukor MS, Aftab K, Norazlina M, Effendi Halmi M, Sheikh A, Shukor M. Isolation of a Novel Molybdenum-reducing and Azo Dye Decolorizing Enterobacter sp. Strain Aft-3 from Pakistan. Chiang Mai Univ J Nat Sci. 2016 Jan 1;15:95-114.
An SY, Min SK, Cha IH, Choi YL, Cho YS, Kim CH, et al. Decolorization of triphenylmethane and azo dyes by Citrobacter sp. Biotechnol Lett. 2002 June 1;24(12):1037-40.
Jadhav JP, Parshetti GK, Kalme SD, Govindwar SP. Decolourization of azo dye methyl red by Saccharomyces cerevisiae MTCC 463. Chemosphere. 2007;68(2):394-400.
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Copyright (c) 2025 Aftab Khan, Motharasan Manogaran, Mohd Izuan Effendi Halmi, Mohd Yunus Shukor
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