Cooperation of fungal laccase and glucose 1-oxidase in transformation of Bjorkman lignin and some phenolic compounds

A screening of wood-rotting basidiomycete fungi was conducted for glucose l-oxidase (GOD) and laccase (LAC) production as well as for ligninolytic activity measured by a Rhemazol reaction. The results showed that genera rich in GOD are lignin degraders as well as effective producers of extracellular LAG. The fungi poor in GOD neither showed LAG, nor ligninolytic activity. The Bjorkman lignin and 3 phenolic compounds, hydroquinone and syringic and vanillic acids, were tested on the sequential activity of LAC and GOD. In the presence of LAG, quinoid intermediates formed from Bjorkman lignin and phenolic compounds were observed. The addition of GOD caused a diminution of the quinone level. During incubation of Bjorkman lignin with LAC and GOD depolymerization occurred, and in the experiments omitting GOD the quantities of low molecular products were markedly lower. Consequently, the consecutive ping-pong activity of LAC and GOD reduced the polymerization and improved the efficiency of depolymerization processes.