Oxidative polymerisation of models for phenolic lignin end-groups by laccase
2010 (English)In: Holzforschung, ISSN 0018-3830, Vol. 64, no 1, 21-34 p.Article in journal (Refereed) Published
The redox enzyme laccase can lead to cross-linking of lignin molecules by oxidising phenolic end groups to resonance-stabilised radicals that can undergo radical coupling to form covalent bonds. This property has potential for many technical applications. However, laccase treatment can also lead to degradation. Experiments were performed with two laccases of different oxidation potential and pH and temperature optima. The predominant reaction following laccase oxidation is the formation of 5-5' and 4-O-5' bonds. If the 5-position is blocked, other reactions occur, including coupling of the 1-position and oxidation of the a-position, which aggravates cross-linking of different lignin molecules. The product profile generated by the two laccases is somewhat different, mainly because of the different pH rather than differences in enzyme activity. Reaction mechanisms and the technical and biological significance of the results are discussed.
Place, publisher, year, edition, pages
2010. Vol. 64, no 1, 21-34 p.
biotechnology, laccase, lignin, lignin model compound, lignin, polymerisation, phenolic end group, reaction mechanism, flight mass-spectrometry, kraft pulp, mediator, delignification, degradation, quinones, polymers, oxidase, oxygen, ms
Paper, Pulp and Fiber Technology
IdentifiersURN: urn:nbn:se:kth:diva-19138DOI: 10.1515/hf.2010.001ISI: 000273912800004ScopusID: 2-s2.0-74049119347OAI: oai:DiVA.org:kth-19138DiVA: diva2:337185
QC 201005252010-08-052010-08-052012-03-22Bibliographically approved