APPLICATION OF TRICHODERMA REESEL CELLULASES FOR DEGRADATION OF CELLULOSIC COMPOUNDS

Abstract

Trichoderma reesei strains QM9414 and Rut C30 may be cultivated on spent brewery grains adjusted to an optimal moisture level of 80% using Trichoderma Medium, Rut C30 Medium or water. The optimal period for growth and enzyme production is 2-4 days for T.reesei QM9414 and 5-7 days for T.reesei Rut C30. Growth and production of cellulases and hemicellulases by both organisms on semi-solid spent grains surpassed that in liquid carboxymethyl cellulose medium. Optimal levels of cellulases, ?-glucosidase and hemicellulases synthesized by T.reesei QM9414, and measured in International Units (IU) per gram cellulose, were 640 IU of Grains-hydrolyzing cellulase complex (GHCC), 259 IU of endoglucanase, 14.3 IU of Filter paperase (FPase), 71 IU of Avicelase, 113 IU of ?-glucosidase, 2920 IU of xylanase, 23 IU of ?-xylosidase and 17 IU of ?-arabinosidase. The cultivation of T.reesei Rut C30 generally produced higher levels of enzymes; 1139 IU of GHCC, 840 IU of endoglucanase, 91 IU of FPase, 205 IU of Avicelae, 83 IU of ?-glucosidase, 6400 IU of xylanase, 24 IU of ?-xylosidase and 22 IU of ?-arabinosidase. The incorporation of soyabean residues as a supplementary nitrogen source and the use of alkali pretreated spent grains as a cultivation substrate did not improve cellulose and hemicellulose synthesis. However, alkali-treated spent grains as saccharification substrates were more readily hydrolyzed by Trichoderma enzymes. Up to 86% hydrolysis of the cellulosic component of the spent grains could be attained. These observations could be confirmed through High Performance Liquid Chromatography Trichoderma QM9414 grown on untreated spent grains were found to possess the entire range of the essential amino acids for poultry feeding. Furthermore, higher levels of the amino acide lysine, histidine, glycine, serine, methionine cystine, phenylalanine and tyrosine were measured in the biologically treated spent grains. Poultry rations incorporated with either Trichoderma-treated or untreated spent grains supported the growth of broilers with adverse effects. There were significant improvements in feed utilization by broilers in the first 4 weeks on incorporating 12% of Trichoderma-treated grains compared to that of the chickens fed control rations or rations supplemented with 4% and 12% untreated grains. In addition, growth at 8% and 12% incorporation and Trichoderma-treated grains was significantly better than that of poultry fed commercial rations.