Nuclear magnetic resonance spectroscopic studies on the microbial degradation of mononitrophenol isomers

Shabana, Basheer and Kunhi, A. A. M. and Varadaraj, M. C. and Divakar, S. (2007) Nuclear magnetic resonance spectroscopic studies on the microbial degradation of mononitrophenol isomers. World Journal of Microbiology and Biotechnology, 23. pp. 49-63.

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Abstract

The biochemical pathways followed by a mixed bacterial culture and one of its constituent strains, Sarcina maxima, MTCC 5216 (hitherto unreported) during the degradation of mononitrophenol isomers was studied using extensive nuclear magnetic resonance (NMR) spectroscopy (One- and Two- Dimensional Heteronuclear Multiple Quantum Coherence Transfer-2D HMQCT NMR). NMR investigations revealed that o-nitrophenol (ONP) could be degraded by the consortium to metabolites such as catechol, cis, cis-muconic acid, c-hydroxymuconic semialdehyde, maleylacetate and b-ketoadipate. The spectra of ONP reaction mixture degraded by S. maxima showed that formation of maleylacetate from c-hydroxymuconic semialdehyde should go through a new metabolite c-hydroxymaleylacetate, hitherto unreported. The consortium could breakdown m-nitrophenol (MNP) to 4-aminocatechol indicating that it came from 3-hydroxyaminophenol. However, S. maxima MTCC 5216, could convert MNP to hitherto unreported 2-nitrohydroquinone and the subsequent 2-hydroxylaminohydroquinone to 1,2,4-benzenetriol along with c-hydroxymuconic semialdehyde, muconolactone and maleylacetate. The pathway followed by the consortium during p-nitrophenol (PNP) degradation was by the formation of 4-nitrocatechol, maleylacetate and b-ketoadipate. PNP reaction mixture of S. maxima, MTCC 5216 on the other hand, showed that the pathway could proceed through the formation of p-hydroquinone as the initial metabolite. The present study conclusively established the nitrophenoldegrading ability of both the consortium and S. maxima MTCC 5216, including exhibiting slight deviations from the pathways followed by the other reported microorganisms.

Item Type:	Article
Uncontrolled Keywords:	Mononitrophenols Degradation Bacterial consortium Sarcina maxima MTCC 5216 NMR Metabolites c-Hydroxymaleylacetate 2-Nitrohydroquinone 2-Hydroxylaminohydroquinone
Subjects:	500 Natural Sciences and Mathematics > 04 Chemistry and Allied Sciences > 10 Spectroscopic and Spectrometric analysis
Divisions:	Fermentation Technology and Bioengineering Human Resource Development
Depositing User:	Food Sci. & Technol. Information Services
Date Deposited:	30 Jun 2009 11:53
Last Modified:	28 Sep 2018 11:03
URI:	http://ir.cftri.res.in/id/eprint/9134

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