Enzymes produced by soil fungi following microaerobic growth on lignocellulosic materials

Four fungal strains able to grow under low oxygenation conditions were sele cted and used in studies to determine the production of enzymes (endoglucan ases, exoglucases, beta-glucosidase, and peroxidases) that promote the degr adation of lignocellulosic materials. The capacity of the fungi to ferment lignocellulosic materials was also investigated. Avicel, xylan, Whatman no. 1 filter paper, or agroindustrial residues were used as carbon sources in a medium containing mineral salts, vitamins, and cysteine as a reducing age nt, under either microaerophilic or combined conditions (aerobic followed b y microaerophilic conditions). The results obtained with strains Q10, H2, a nd LH5 suggest that they prefer a low oxygen concentration for growth and e nzyme production. However, strain F20 seems to need higher levels of oxygen ation. Lignocellulolytic activities were detected in all strains but varied with the carbon source used for growth. In general, the highest levels of these activities were produced by strain H2 under microaerophilic condition s. Ethanol and other nongaseous fermentation products were detected followi ng high-performance liquid chromatography analysis using a Supelcogel C-610 H column, demonstrating the fermentative capability of these strains.