CELLULOLYTIC AND HEMICELLULOLYTIC ENZYMES FROM Trichoderma STRAINS ISOLATED FROM CORN CULTURE

The fungi of the genus Trichoderma are ascomycetes that live in diverse habitats. They can be isolated from temperate and tropical soils. For the substrate decomposition, these fungi secrete enzymatic complexes that besides helping in their colonization to the environment also provide protection against competitors. Due to these characteristics, Trichoderma and its secondary metabolites are widely used in studies against plant pathogens, biological fungicides, applications as antibiotics and in the production of enzymes of biotechnological interest. Therefore, the aim of this study was to evaluate the cellulolytic and hemicellulolytic potential of Trichoderma strains by solid state fermentation in sugarcane bagasse. The strains were isolated from different maize growing areas of Londrina-PR by the department of agronomy of the State University of Londrina and identified as genus Trichoderma (Th1, 2, 3, 4, 5, 6 and 7). The solid state fermentation was developed in 125 mL Erlenmeyers containing 3.5 g of sugarcane bagasse moistened with 25 mL of Vogel solution, inoculated with 1 mL of spore suspension (1 x 108 UFC mL-1) in 0.1 % (v/v) tween 80 and incubated at 28 ± 2 °C for seven days. The crude enzymatic extract was obtained by the addition of 25 mL of distilled water to the fermented material that was homogenized, centrifuged (9,000 rpm for 15 minutes) and used to determine the activities of the enzymes cellulases, β-glycosidases and xylanases. The Th7 was the best producer of cellulase with activity of 21.4 Ugss-1 followed by Th2 with 20.8 Ugss-1. Th1, 3, 4 and 5 produced on average 17 Ugss-1 of cellulase and the Th6 was the one with the lowest cellulolytic activity with 11.9 Ugss-1. The activities of β-glucosidases ranged from 0.4 Ugss-1 (Th3) to 1.6 Ugss-1 (Th2). Xylanases activities was the lowest among the enzymes, Th2 was the best producer with 0.15 Ugss-1 and Th4 was the worse with 0.02 Ugss-1. The results showed that sugarcane bagasse was an efficient substrate for the growth of strains, indicating its potential for cultivation of fungi by solid state fermentation. The strains were able to produce the 3 enzymes studied, highlighting the production of cellulases.