Early attack and subsequent changes produced in an industrial lignin by a fungal laccase and a laccase-mediator system: an analytical approach

An industrial kraft pine lignin (Indulin AT, KL) was characterized and treated in both aqueous-buffered media and dioxane to water, either with a partially purified laccase from Fusarium proliferatum or with the laccase plus 2,2′-azino-bis-3-ethylbenzothiazoline-6-sulfonic-acid (ABTS) as mediator. The changes in the lignin after different incubation periods were analyzed through the application of high performance liquid chromatography (HPLC), UV-visible (Vis) spectroscopy and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). At the onset of incubation, laccase-treated samples showed a slight polymerization and strong modifications in UV-Vis spectra. Through Py-GC/MS, a decrease in phenolic and methoxy-bearing pyrolysis products was observed, in contrast to an increase in the more oxidized products. After longer incubation periods (48 h) a substantial polymerization was detected by HPLC, along with a decrease in the guaiacyl (G) units. In contrast, the analysis by HPLC of the samples recovered from the laccase-ABTS system (LMS) showed an intense depolymerization, accompanied by a sizeable loss in G units and a decrease in the methyl and ethyl side-chain phenolic compounds. These results provide conclusive evidence of a rapid initial attack of the industrial lignin by laccase and notable modifications in the KL after longer incubation periods with laccase or LMS. © 2006 Springer-Verlag.

Bibliographic Details

Main Authors:	González Arzola, K., Polvillo, Oliva, Arias Fernández, Mª E., Perestelo, F., Carnicero, A., González-Vila, Francisco Javier, Falcón, M. A.
Other Authors:	Ministerio de Ciencia y Tecnología (España)
Format:	artículo biblioteca
Language:	English
Published:	Springer 2006
Online Access:	http://hdl.handle.net/10261/57946 http://dx.doi.org/10.13039/501100006280
Tags:	Add Tag No Tags, Be the first to tag this record!