CHEMICAL ASSESSMENT OF LIGNIN BIODEGRADATION SOME QUALITATIVE AND QUANTITATIVE ASPECTS

The molecular structure of lignins (occurrence of condensed and non-co ndensed monomeric units and associations with phenolic acids by ether and ester linkages) have been reviewed in this paper. Critical aspects of chemical determination of lignin content and monomeric composition have been discussed in the case of nitrobenzene oxidation and thioaci dolysis. As an example of assessment of lignin biodegradation by perox idases, lignin peroxidase and horseradish peroxidase have been compare d, indicating that horseradish peroxidase is a ligninolytic enzyme, co nfirming the influence of the physical state of lignins on their biode gradability and the general difficulty to characterize biomacromolecul es.