Production of cellulolytic and xylanolytic enzymes during growth of anaerobic fungi from ruminant and nonruminant herbivores on different substrates.

Three anaerobic fungi, two Neocallimastix strains isolated from a ruminant (sheep) and one Piromyces strain isolated from a nonruminant (black rhinoceros), were tested for their ability to ferment a range of substrates. Bagasse, filter paper cellulose, fructose, and wheat straw were good inducers of celluloytic and xylanolytic enzymes. These enzymes were produced constitutively by all three strains, although enzyme activities were generally lower, especially for both Neocallimastix strains, after growth on glucose and other soluble sugars. The isoenzyme patterns of extracellular enzyme preparations of Neocallimastix strains were influenced by the growth substrate.