Effect of carbohydrate and nitrogen on hydrogen peroxide formation by wood decay fungi in solid medium

Abstract Hydrogen peroxide (H₂O₂) has been implicated in degradation of wood by both brown-rot and white-rot fungi. This study found that low concentrations of nitrogem and carbohydrates (cellobiose, glucose, xylose and mannose) in an agar medium had little effect on H₂O₂ production by white-rot fungi. However, low concentrations of nitrogen and carbohydrates stimulated H₂O₂ production by brown-rot fungi. Use of the chromogen 2,2'-azino-di(3-ethyl benzthiazoline-6-sulphonic acid) (ABTS) with horseradish peroxidase to detect H₂O₂ by the fungi was slightly better than detection by the chromogen o -dianisidine with horseradish peroxidase. An auxiliary test to check the role of H₂O₂ in wood decay found that hydrogen peroxide-negative isolates of the white-rot fungi Pharnerochaete chrysosporium and Ganoderma applanatum were unable to decay sweetgum and southern pine.