Siderophores as natural mediators in laccse-aided degradation of lignin

Marja-Leena Niku-Paavola, H. Anke, K. Poppius-Levlin, Liisa Viikari

Research output: Chapter in Book/Report/Conference proceedingConference article in proceedingsScientificpeer-review


Hydroxamate siderophores, microbial metal chelating agents have structural similarities with synthetic mediators succesfully used in laccase-aided delignification processes. The iron-free forms of fungal hydroxamate siderophores; desferrioxamine B, desferritriacetylfusigen and nocardamin, were shown to have mediator characteristics in laccase catalyzed oxidative reactions. Ferricrosin, an iron-containing form of siderophore, did not react with laccase. It was concluded that the iron-binding structures, free hydroxyl groups in the hydroxamate siderophores, are the targets for laccase. GPC, 1H NMR and 13C NMR analysis indicated degradation and modification of siderophores during oxidation by laccase. The reaction mechanism differs from the corresponding reactions of synthetic mediators. When compared on molar basis, the ability of the oxidized siderophore to degrade lignin was better than that obtained by the synthetic mediator 1 hydroxybenzotriazole (HBT), due to the higher number of N-OH-groups in the siderophore molecule. The role of siderophores as natural mediators in delignification and as models for mediators is thus worth of further evaluation.
Original languageEnglish
Title of host publicationApplications of Enzymes to Lignocellulosics
EditorsShawn D. Mansfield, John N. Saddler
PublisherAmerican Chemical Society ACS
ISBN (Electronic)978-0-8412-1960-1
ISBN (Print)978-0-8412-3831-2
Publication statusPublished - 2003
MoE publication typeA4 Article in a conference publication
Event223rd ACS National Meeting - Orlando, United States
Duration: 7 Apr 200211 Apr 2002

Publication series

SeriesACS Symposium Series


Conference223rd ACS National Meeting
Country/TerritoryUnited States


Dive into the research topics of 'Siderophores as natural mediators in laccse-aided degradation of lignin'. Together they form a unique fingerprint.

Cite this