Media carbon induction of extracellular cellulase activities inNeocallimastix frontalis isolate EB188

Extracellular cellulase induction in the ruminal fungusNeocallimastix frontalis isolate EB188 was followed. Glucose media-established cultures produced cellulase when switched to a variety of cellulose-containing media. High levels of cellulase and xylanase activities were present in cultures switched to sigma cell 100, solka floc, avicel, sisal fiber, and wheat straw, but not those switched to glucose, carboxymethylcellulose, or wood chips. Several assay substrates were used to show differential cellulase induction as well as-glucosidase activity. Cellulases hydrolyzed short oligosaccharides and released glucose from insoluble cellulose. Cellobiase activity was also indicated. Cellulase activity tolerated brief exposure to high temperature, was insensitive to certain metal ions, and possessed pH optima between 5.0 and 6.5.