Catabolism of 1,2-diarylethane lignin model compounds by two brown-rot fungi

The catabolism of dimethoxybenzil, anisoin and hydroanisoin in nitrogen-limited stationary cultures of the brown-rot fungi Wolfiporia cocos and Gloeophyllum trabeum was analyzed. These three 1,2-diarylethane lignin model compounds, which differ in the degree of oxidation of the alkylic chain, gave rise to p-anisaldehyde in both cultures, suggesting that cleavage between the two aliphatic carbons had occurred. In turn, both strains reduced dimethoxybenzil and anisoin to hydroanisoin, whereas only Wolfiporia cocos was able to oxidize hydro-anisoin to anisoin. On the other hand, chemically derived hydroxyl radical, but not superoxide radical, produced p-anisaldehyde plus other unidentified compounds from anisoin and hydroanisoin. Neither radical modified dimethoxybenzil significantly.Abbreviations HGLN high glucose, low nitrogen - HGHN high glucose, high nitrogen - HPLC high performance liquid chromatography - TLC thin layer chromatography - A anisoin - HA hydroanisoin - DMB dimethoxybenzil - OH Hydroxyl radical - O _inf2 ^sup- superoxide radical