Please use this identifier to cite or link to this item: https://doi.org/10.1016/S0141-0229(02)00016-9
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dc.titleOrtho pathway of benzoate degradation in Pseudomonas putida: Induction of meta pathway at high substrate concentrations
dc.contributor.authorLoh, K.-C.
dc.contributor.authorChua, S.-S.
dc.date.accessioned2014-10-09T09:57:53Z
dc.date.available2014-10-09T09:57:53Z
dc.date.issued2002-05-02
dc.identifier.citationLoh, K.-C., Chua, S.-S. (2002-05-02). Ortho pathway of benzoate degradation in Pseudomonas putida: Induction of meta pathway at high substrate concentrations. Enzyme and Microbial Technology 30 (5) : 620-626. ScholarBank@NUS Repository. https://doi.org/10.1016/S0141-0229(02)00016-9
dc.identifier.issn01410229
dc.identifier.urihttp://scholarbank.nus.edu.sg/handle/10635/92200
dc.description.abstractThe growth of Pseudomonas putida ATCC 49451 on various concentrations of sodium benzoate was examined under batch cultivation. At low initial concentrations (≤400 mgl-1), cell growth rate was described by the Monod model with parameters of maximum specific growth rate, μm = 0.66 h-1 and saturation constant, Ks = 10 mgl-1. At higher initial concentrations (≥500 mgl-1), product inhibition on specific growth and degradation rates was observed; specific growth rate decreased as sodium benzoate was degraded. A change in degradation pathway was observed with different initial concentrations of sodium benzoate. With initial concentrations up to 200 mgl-1, catechol was oxidized via the ortho ring cleavage with the induction of catechol 1,2-dioxygenase. The ortho pathway metabolites namely, catechol, cis, cis-muconate and muconolactone, were identified using gas chromatography/mass spectrometry (GC/MS) after trimethylsilyl (TMS) derivatization. When higher initial concentrations of sodium benzoate were used (≥300 mgl-1), the culture media showed absorbance at 375 nm (A375) during the later stage of degradation after approximately 200 mgl-1 of sodium benzoate has been transformed. This was attributed to the accumulation of 2-hydroxymuconic semialdehyde (HMSA), which is an intermediate metabolite of the meta ring fission of catechol. It is concluded that cells grown on high enough concentrations of sodium benzoate simultaneously induced catechol 1,2-dioxygenase and catechol 2,3-dioxygenase, thus activating both the ortho and the meta catechol cleavage pathways. It was further found that catechol, a metabolic intermediate of sodium benzoate, did not effectively support the growth of P. putida when used as a sole substrate. Instead, a dark brown polymerization product was formed. We infer that the induction of the meta pathway is a consequence of the accumulation of 1,2-dihydro-1,2-dihydroxybenzoate (DHB) in the media. © 2002 Elsevier Science Inc. All rights reserved.
dc.description.urihttp://libproxy1.nus.edu.sg/login?url=http://dx.doi.org/10.1016/S0141-0229(02)00016-9
dc.sourceScopus
dc.subject2-Hydroxymuconic semialdehyde
dc.subjectBenzoate
dc.subjectCatechol
dc.subjectGas chromatography/mass spectrometry
dc.subjectInhibition
dc.subjectMeta pathway
dc.subjectOrtho pathway
dc.subjectPseudomonas putida
dc.typeArticle
dc.contributor.departmentCHEMICAL & ENVIRONMENTAL ENGINEERING
dc.description.doi10.1016/S0141-0229(02)00016-9
dc.description.sourcetitleEnzyme and Microbial Technology
dc.description.volume30
dc.description.issue5
dc.description.page620-626
dc.description.codenEMTED
dc.identifier.isiut000175382800007
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