IJEP 43(8): 675-685 : Vol. 43 Issue. 8 (August 2023)
1. North Gauhati College, Department of Botany, Guwahati, Assam – 781 031, India
2. B. Borooah College, Department of Botany, Guwahati, Assam – 781 007, India
Environmental contamination through aromatic hydrocarbons is a global concern among the scientific community. Environment is often polluted with monocyclic and polycyclic aromatic hydrocarbons through industrial discharges, accidental spills, gasoline, leakages, etc. Bacillus strains are commonly found in the soil and have outstanding potential to degrade such compounds to non-toxic or less toxic metabolites. This study aims to isolate, characterize and identify Bacillus strains from oil contaminated soil of Guwahati Refinery and to determine their potentiality to degrade monocyclic aromatic hydrocarbon: toluene and xylene. Out of 21 isolates, Bacillus subtilis designated as RD20 has shown significant biodegradation potentiality of these two mono-aromatic hydrocarbons and is thus selected for the present study. Biodegradation of compounds was determined through FTIR and GCMS studies. Detection of certain intermediate metabolites through GCMS suggested the degradation of the compounds by the bacterial strain. The metabolites obtained in toluene degrading pathway were identified as benzene acetic acid, 1,3-benzenediol, cyclopentane-1,2-diol, acetic acid, 2-propanol, butanoic acid, phthalic acid, hexanoic acid, propiolic acid, hexanedioic acid and propionic acid. However, the metabolites, such as benzene methanol (benzyl alcohol), cyclobutane carboxylic acid, phenol, formic acid, cyclopropane, acetic acid, phthalic acid, 1,3-cyclopentane carboxylic acid and succinic acid were obtained in xylene degradation pathway through GCMS study. Thus it has been found that the bacterial isolate transformed toluene and xylene into its relatively less toxic metabolites and therefore, Bacillus subtilis RD20 may be exploited as bioremediation agent of these two aromatic hydrocarbons.
Bacillus subtilis, Biodegradation, FTIR, GCMS, Toluene, Xylene, Metabolites, Monocyclic aromatic hydrocarbon
- Jacob, J.H. and F.I. Irshaid. 2015. Toluene biodegradation by novel bacteria isolated from polluted soil surrounding car body repair and spray painting workshops. J. Env. Prot., 6: 1417-1429.
- Smith, M.R. 1990. The biodegradation of aromatic hydrocarbons by bacteria. Biodegrad., 1:191–206.
- Gibson, D.T. and V. Subramanian. 1984. Microbial degradation of aromatic hydrocarbons. In Microbial degradation of organic compounds. Ed D.T. Gibson. Marcel Dekker, New York. pp 181-252.
- Undugoda, L.J.S., et al. 2018. Plasmid encoded toluene and xylene degradation by phyllosphere bacteria. J. Env. Toxicol., 8: 559.
- Singh, A.P. and G.S. Bennett. 2009. Isolation and characterization of benzene degrading bacteria from gasoline contaminated water. Clean Tech., 9: 286-289.
- Mittal, A. and P. Singh. 2009. Isolation of hydrocarbon degrading bacteria from soils contaminated with crude oil spills. Indian J. exp. Biol., 47(9):760-765.
- Guru, G.S., et al. 2013. Isolation and enrichment of microbes for degradation of crude oil. Int. J. Eng. Sci. Innov. Tech., 2(4): 144-147.
- Muccee, F., S. Ejaz and N. Riaz. 2019. Toluene degradation via a unique metabolic route in indigenous bacterial species. Arch. Microbiol., 201: 1369-1383.
- Parales, R.E, et al. 2008. Diversity of microbial toluene degradation pathways (chapter 1). Adv. Appl. Microbiol., 64:1-73.
- Ranya, A.A., M.N. Mahmoud and E.R. El-Helow. 2008. Biodegradation of monocyclic aromatic hydrocarbons by a newly isolated Pseudomonas strain. Biotech., 7: 630-640.
- Atlas, R.M. and C.E. Cerniglia. 1995. Bioremediation of petroleum pollutants- Diversity and environmental aspects of hydrocarbon biodegradation. Biosci., 45:332-338.
- Gillespie, I.M.M. and J.C. Philp. 2013. Bioreme-diation an environmental remediation technology
for the bioeconomy. Trends Biotech., 31: 329-
- Cerquira, V.S., et al. 2011. Biodegradation potential of oily sludge by pure and mixed bacterial cultures. Biores. Tech., 102(23): 11003–11010.
- Fernandez-Luqueno, F., et al. 2011. Microbial communities to mitigate contamination of PAHs in soil-Possibilities and challenges: A review. Env. Sci. Poll. Res., 18: 12-30.
- Mandri, T. and J. Lin. 2007. Isolation and characterization of engine oil degrading indigenous microorganisms in Kwazulu-Natal, South Africa. African J. Biotech., 6(1):23-27.
- Borah, D. and R.N.S. Yadav. 2014. Optimization of BH medium for efficient biodegradation of diesel, crude oil and used engine oil by a newly isolates B. cereusstrain DRDU1 from an automobile engine. Biotech., 13(4):181-185.
- Jayanthi, R. and N. Hemashenpagam. 2015. Optimization of BH medium for efficient biodegradation of benzene, toluene and xylene by a Bacillus cereus. Int. J. Curr. Microbiol. Appl. Sci., 4(10): 807-815.
- Olukunle, O.F., O. Babajide and B. Boboye. 2015. Effects of temperature and pH on the activities of catechol 2,3-dioxygenase obtained from crude oil contaminated soil in Ilaje, Ondo state, Nigeria. Open Microbiol. J., 9: 84-90.
- Cappuccino, J.G. and N. Sherman. 2005. Microbiology: A laboratory manual (7th edn). Benjamin/ Cummings Science Publishing, California.
- Krieg, N.R., et al. 1984. Bergeys Manual of Systematic Bacteriology. Springer New York. pp 86, 89a and b.
- Claus, D. 1992. A standardized Gram staining procedure. World J. Microbiol. Biotech., 8(4):451–452.
- Das, K. and A.K. Mukherjee. 2007. Crude petroleum-oil biodegradation efficiency of Bacillus subtilis and Pseudomonas aeruginosa strains isolated from a petroleum-oil contaminated soil from northeast India. Biores. Tech., 98(7):1339-1345.
- Mukherjee, A.K. and N.K. Bordoloi. 2012. Biodegradation of benzene, toluene and xylene (BTX) in liquid culture and in soil by Bacillus subtilis and Pseudomonas aeruginosa strains and a formulated bacterial consortium. Env. Sci. Poll. Res., 19(8): 3380-3388.
- Dutton, P.L. and W.C. Evans. 1969. The metabolism of aromatic compounds by Rhodopseudomonas palustris. Biochem. J., 113: 525–536
- Zylstra, G.J. and D.T. Gibson. 1991. Aromatic hydrocarbon degradation: A molecular approach. In Genetic engineering. Ed J.K. Setlow. Plenum Press, New York.
- Worsey, M.J. and P.A. Williams. 1975. Metabolism of toluene and xylenes by Pseudomonas putida (arvilla) mt-2: Evidence for a new function of the TOL plasmid. J. Bacteriol., 124:7-13.
- Assinder, S.J. and P.A. Williams. 1990. The TOL plasmids: Determinants of the catabolism of toluene and the xylenes. Adv. Microbiol. Physiol., 31:2-69.
- Kimura, M. 1980. A simple method for estimating evolutionary rate of base substitutions through comparative studies of nucleotide sequences. J. Molecular Evol., 16:111-120.
- Felsenstein, J. 1985. Confidence limits on phylogenies: An approach using the bootstrap. Evol., 39: 783-791.
- Shields, M.S., et al. 1989. Novel pathway of toluene catabolism in the trichloroethylene-degrading bacterium G4. Appl. Env. Microbiol., 55(6):1624-1629. doi: 10.1128/AEM.55.6.1624-1629.1989.
- El-Naas, M.H., J.A. Acio and E.A. Telib. 2014. Aerobic biodegradation of BTEX: Progresses and prospects. J. Env. Chem. Eng., 2(2):1104-1122.
- Yu, H., B.J. Kim and B.E. Rittmann. 2001. The roles of intermediates in biodegradation of benzene, toluene and p-xylene by Pseudomonas putida F1. Biodegrad.,12:455–463.
- Zhang, L., et al. 2013 Biodegradation of benzene, toluene, ethyl benzene and o-xylene by the bacterium Mycobacterium cosmeticum byf-4. Chemosphere. 90(4): 1340–1347.
- Madigan, M. T., J. M. Martinko and J. Parker. 2000. Brock biology of micro-organisms. Prentice-Hall, Inc., New York.
- Rittmann, B.E. and P.L. McCarty. 2001. Environmental biotechnology: Principles and applications. McGraw-Hill Book Co., New York.
- Davey, J.F. and D.T. Gibson. 1974. Bacterial metabolism of para and meta-xylene: oxidation of a methyl substituent. J. Bacteriol., 119:923-929.
- Cao, B., K. Nagarajan and K.C. Loh. 2009. Biodegradation of aromatic compounds: Current status and opportunities for biomolecular appro-aches. Appl. Microbiol. Biotech.,85:207-228. DOI:10.1007/s00253-009-2192-4.
- Lee, Y., Y. Lee and C.O. Jeon. 2019. Biodegradation of naphthalene, BTEX and aliphatic hydrocarbons by Paraburkholderia aromaticivorans BN5 isolated from petroleum-contaminated soil. Sci. Reports. 9: 860.
- Choi, E.J., et al. 2012. Comparative genomic analysis and benzene, toluene, ethyl benzene and o-m- and p-xylene (BTEX) degradation pathways of Pseudoxanthomonas spadix BD-a59. Appl. Env. Microbiol., 79 (2) : 663-671.
- Ramos, J.L., N. Mermod and K.N. Timmis. 1987. Regulatory circuits controlling transcription of TOL plasmid operon encoding meta-cleavage pathway for degradation of alkyl benzoates by Pseudomonas. Mol. Microbiol., 1:293-300.
- Mazzeo, D.E.C., et al. 2010. BTEX biodegradation by bacteria from effluents of petroleum refinery. Sci. Total Env., 408(20):4334–4340.
- Gibson, D.T, V. Mahadevan and J.F. Davey. 1974. Bacterial metabolism of paraand meta-xylene: Oxidation of the aromatic ring. J. Bacteriol., 119:930-936.
- Barbieri, P., et al. 1993. Alternative pathways for o-xylene or m-xylene and p-xylene degradation in a Pseudomonas stutzeri strain. Biodegrad., 4:71-80.
- Bramucci, M.G., et al. 2002. Pure bacterial isolates that convert p-xylene to terephthalic acid. Appl. Microbiol. Biotech., 58:255-259.
- Wang, X., et al. 2015. Degradation pathway and kinetic analysis for p-xylene removal by a novel Pandoraea sp. strain WL1 and its application in a biotrickling filter. J. Hazard. Mater., 288:17–24.