Cellulases and xylanase production by x-ray-induced mutants of Trichoderma viride M4-4

Five new mutants were obtained by a two-stage (UV + X-ray) mutation of T. viride C-1. The selected mutants were tested for producticn of cellulases and xylanase in submerged cultivation in shake flasks in a Saunders medium containing 2% microcrystalline cellulose, 2% dry sugar beet pulp, 0.5% yeast extract and 0.5% wheat germs. Activities in biosynthesis of cellulases and xylanase were assayed at various time intervals in culture filtrates. The mu tants obtained after two-stage mutation (UV + X) were characterized by considerably higher activity in biosynthesis of extracellular cellulases than the natural strain, but similar or lower than the UV-mutant T. viride M4-4. Extracellula '. ß-xylanase activity of some examined mutants was higher (40 - 155% on average) in comparison to the natural strain T. viride C-1 as weil as to the UV-mutant T. v iride M4-4 strain.