| Abstract: | The cellulolytic properties of a Chaetomium crispatum strain were investigated. The cellulolytic enzyme complex i.e.: exo-1,4-β-glucosidase (EC 3.2.1.74); endo-1,4-β-glucanase (EC 3.2.1.4.) and β-glucosidase or cellobiase (EC 3.2.1.21) displayed optimal activity at pH 5.0 and 25°C. Although carboxymethyl-celluloses are the usual pseudo-substrates for this enzyme complex, those with a high degree of substitution gave rise to poor growth and low cellulase activity. Insoluble crude cellulosics such as newsprint, recycled paper, rice and flax straw were substantially solubilised at 28°C within 3–5 days of fermentation. A study of the cellulase-complex formation during the growth cycle revealed that β-glucosidase was produced mainly intracellularly in the early exponential phase, while the overall exo-1,4-β-glucosidase and endo-1,4-β-glucanase formation gradually increased during the total fermentation cycle. The mycelial protein of Chaetomium crispatum grown on crude cellulosics displayed a favourable amino acid pattern, indicating its potential value as a source of single cell protein (SCP). |
