Bioconversion of methanol to formaldehyde.: II.: By purified methanol oxidase from modified yeast, Hansenula polymorpha

dc.contributor.authorSagiroglu, Ayten
dc.contributor.authorAltay, Volkan
dc.date.accessioned2024-06-12T11:08:27Z
dc.date.available2024-06-12T11:08:27Z
dc.date.issued2006
dc.departmentTrakya Üniversitesien_US
dc.description.abstractModified methylotrophic yeast Hansenula polymorpha (HP A16) that was obtained by repressing leucine oxotrophic yeast; a wild type of Hansenula polymorpha CB4732 was used in this study. The yeast is grown with methanol, which is used as a sole carbon source, using various methanol concentrations and temperatures, and methanol oxidase (MOX) which is a key enzyme of methanol metabolism; production is maximized. Whole yeast cells were cultivated under optimized inoculation conditions; they were separated into two portions. One portion of these cells was directly used in bioconversion of methanol to formaldehyde. The second portion of the free cells was broken into pieces and a crude enzyme extract was obtained. The MOX enzyme in this extract was purified via salt precipitation, dialysis, and chromatographic methods. The purified MOX enzyme of yeast (HP A16) oxidized the methanol to formaldehyde. Optimization of bioconversion conditions was studied to reach maximum activity of enzyme. The optimum temperature and pH were found to be 35 degrees C and pH 8.0 in boric acid/NaOH buffer, and it was stable over the pH range of 6 9, at the 20 degrees C 15 min. A suitable reaction period was found as 50 min. The enzyme indicated low carbon primary alcohols (C-2 to C-4), as well as methanol. Initially, MOX activity increased with the increase of methanol concentration, but enzyme activity decreased. The apparent K-m and V-max values for methanol substrate of HP A16 MOX were 0.25 mM and 30 U/mg, respectively. The purified MOX enzyme was applied onto sodium dodecyl sulphate-polyacrylamide gel electrophoresis; molecular weight of the enzyme was calculated to be about 670 kDa. Each MOX enzyme is composed of eight identical subunits, each of whose molecular weight is around 82 kDa and which contain eight moles of FAD as the prosthetic group, and the pI of the natural enzyme is found to be 6.4. The purified MOX enzyme was used in the bioconversion of methanol to formaldehyde as a catalyst; this conversion was compared to the conversion percentages of whole cells in our previous article in terms of catalytic performances.en_US
dc.identifier.doi10.1080/10826060600959659
dc.identifier.endpage332en_US
dc.identifier.issn1082-6068
dc.identifier.issn1532-2297
dc.identifier.issue4en_US
dc.identifier.pmid16971303en_US
dc.identifier.scopus2-s2.0-33748698616en_US
dc.identifier.scopusqualityQ3en_US
dc.identifier.startpage321en_US
dc.identifier.urihttps://doi.org/10.1080/10826060600959659
dc.identifier.urihttps://hdl.handle.net/20.500.14551/22441
dc.identifier.volume36en_US
dc.identifier.wosWOS:000240490900004en_US
dc.identifier.wosqualityQ4en_US
dc.indekslendigikaynakWeb of Scienceen_US
dc.indekslendigikaynakScopusen_US
dc.indekslendigikaynakPubMeden_US
dc.language.isoenen_US
dc.publisherTaylor & Francis Incen_US
dc.relation.ispartofPreparative Biochemistry & Biotechnologyen_US
dc.relation.publicationcategoryMakale - Uluslararası Hakemli Dergi - Kurum Öğretim Elemanıen_US
dc.rightsinfo:eu-repo/semantics/closedAccessen_US
dc.subjectMethylotrophic Yeastsen_US
dc.subjectHansenula Polymorpha <en_US
dc.subjectMethanol Oxidase (MOX)en_US
dc.subjectEnzyme Purification And Characterizationen_US
dc.subjectPolyacrylamide-Gel Systemen_US
dc.subjectAlcohol Oxidaseen_US
dc.subjectProteinen_US
dc.titleBioconversion of methanol to formaldehyde.: II.: By purified methanol oxidase from modified yeast, Hansenula polymorphaen_US
dc.typeArticleen_US

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