Enzymatic modification of lignin by oxidoreductases from wood-degrading fungi

The project will focus on oxidoreductases from the white-rot fungi Trametes versicolor and Phanerochaete chrysosporium, and particularly on the functions of enzymes that have capacity to oxidize lignin or reduce quinones.

The functions of the quinone-reducing enzymes quinone reductase and cellobiose dehydrogenase and their potential interactions with lignin-oxidizing enzymes (lignin peroxidase, laccase, and lytic polysaccharide monooxygenase) will be explored through studies of their catalytic actions and of their secretion patterns under primary metabolism (non-ligninolytic conditions) and secondary metabolism (ligninolytic conditions).

The secretion patterns will be investigated using quantitative proteomics for parallel comparison of multiple protein preparations from fungal cultures The secretion patterns of enzymes with uncertain function will be compared to secretion patterns of enzymes with an established role in biodegradation of cellulose or lignin.

The potential involvement of quinone-reducing enzymes in fungal defense against toxic quinones will also be investigated.

Organisms and enzymes that are involved in the biodegradation of wood and other forms of lignocellulose have important roles in nature as well as in industry.

Investigations of the physiological roles of these enzymes have potential to contribute to a better understanding of decay of organic matter from vascular plants and to more efficient processes for making commodities from renewable resources.