Pathways of 3-Chlorobenzoate Degradation by Rhodococcus opacus strains 1CP and 6a
- Authors: Solyanikova I.P.1, Emelyanova E.V.1, Shumkova E.S.2, Travkin V.M.3
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Affiliations:
- Skryabin Institute of Biochemistry and Physiology of Microorganisms, FRC “Pushchino Scientific Centre of Biological Research”, Russian Academy of Sciences
- Bach Institute of Biochemistry, Research Center for Biotechnology, Russian Academy of Sciences
- Gorin Belgorod State Agrarian University
- Issue: Vol 88, No 5 (2019)
- Pages: 563-572
- Section: Experimental Articles
- URL: https://bakhtiniada.ru/0026-2617/article/view/164104
- DOI: https://doi.org/10.1134/S002626171905014X
- ID: 164104
Cite item
Abstract
3-Chlorobenzoic acid (3-CBA) is widely used as a precursor/preservative in industry and agriculture and is therefore a known environmental contaminant. The key stages of 3-CBA decomposition by Rhodococcus opacus strains 1CP and 6a were studied. Comparative characterization of the substrate specificity of 3-chlorobenzoate 1,2-dioxygenase (3-CBA 1,2-DO), induced in the strains grown in the presence of 3‑CBA, was carried out. These enzymes were established to have a wider substrate specificity than the benzoate 1,2-dioxygenase (1,2-BDO) of R. opacus strain 1CP, which is induced during growth of R. opacus strain 1CP in the presence of benzoate. Benzoate, 3-CBA, and 3,4-dihydroxybenzoate served as substrates for 3‑CBA 1,2-DO. During the degradation of 3-CBA by R. opacus 1CP cells, both 3-chloro- and 4-chlorocatechol (3-CCat and 4-CCat) were detected. R. opacus 6a efficiently degraded 3-CBA without accumulation of intermediates. The difference in the pathways of 3-CBA degradation by these strains was shown: via the pathway of ortho-cleavage of 3-chlorocatechol in R. opacus 1CP and of 4-chlorocatechol in R. opacus 6a. In the genome of the strain R. opacus 6a, the genes encoding chlorocatechol 1,2-dioxygenase and chloromuconate cycloisomerase were found, which were 98-99% identical to the genes of R. opacus 1CP encoding 4‑chlorocatechol 1,2-dioxygenase (4-CCat 1,2-DO) and 3-chloromuconate cycloisomerase (3-CMCI) of the modified ortho-cleavage pathway for conversion of 4-chlorocatechol (the intermediate of 4-chlorophenol degradation). It was shown for the strains under study that implementation of different pathways for 3-CBA decomposition was predestined not by the metabolic capabilities of bacteria, but by the substrate specificity of 3-CBA 1,2-DO, the enzyme that initiates 3-CBA degradation.
About the authors
I. P. Solyanikova
Skryabin Institute of Biochemistry and Physiology of Microorganisms, FRC “Pushchino Scientific Centreof Biological Research”, Russian Academy of Sciences
Author for correspondence.
Email: innas@IBPM.Pushchino.ru
Russian Federation, Pushchino, 142290
E. V. Emelyanova
Skryabin Institute of Biochemistry and Physiology of Microorganisms, FRC “Pushchino Scientific Centreof Biological Research”, Russian Academy of Sciences
Email: innas@IBPM.Pushchino.ru
Russian Federation, Pushchino, 142290
E. S. Shumkova
Bach Institute of Biochemistry, Research Center for Biotechnology, Russian Academy of Sciences
Email: innas@IBPM.Pushchino.ru
Russian Federation, Moscow, 119071
V. M. Travkin
Gorin Belgorod State Agrarian University
Email: innas@IBPM.Pushchino.ru
Russian Federation, May, 308503
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