This study compares two xylanases produced by filamentous fungi such as A. niger and A. flavus using agroindustrial residues as substract and evaluated the effect of these enzymes on cellulose pulp biobleaching process. Wheat bran was the best carbon source for xylanase production by A. niger and A. flavus. The production of xylanase was 18 and 21% higher on wheat bran when we compare the xylanase production with xylan. At 50°C, the xylanase of A. niger retained over 85% activity with 2 h of incubation, and A. flavus had a half-life of more than 75 minutes. At 55°C, the xylanase produced by A. niger showed more stable than from A. flavus showing a half-life of more than 45 minutes. The xylanase activity of A. niger and A. flavus were somehow protected in the presence of glycerol 5% when compared to the control (without additives). On the biobleaching assay it was observed that the xylanase from A. flavus was more effective in comparison to A. niger. The kappa efficiency corresponded to 36.32 and 25.93, respectively. That is important to emphasize that the cellulase activity was either analyzed and significant levels were not detected, which explain why the viscosity was not significantly modified.

Biological control using fungi of the Trichoderma genus has been gaining increasing prominence as a sustainable alternative to synthetic pesticides, particularly due to its ability to suppress phytopathogens and promote plant growth. While the beneficial role of Trichoderma species is well established, research involving native strains from Brazilian biomes remains limited. The present work comprised the investigation of 55 isolates of Trichoderma spp., isolated from the soil or endophytic from the plant species natives to the Pantanal and Cerrado of Mato Grosso do Sul (Brazil), regarding their capacity to inhibit the growth and spread of the phytopathogen Sclerotinia sclerotiorum (Lib.) de Bary. The results from confrontation assays (15.74-30.04 % growth of S. sclerotiorum), paired plate cultures (5.76-39.53 % growth of S. sclerotiorum), and cell wall-degrading enzyme (CWDEs) activity assays-whose activities ranged from 8.791 to 197.593 U mg^-1 for glucanase, 0.059-333.864 U mg^-1 for NAGase, 0.082-37.110 U mg^-1 for acid phosphatase, 1.234-45.716 U mg^-1 for chitinase, and 3.261-304.807 U mg^-1 for protease-were used to select Trichoderma spp. Five strains were selected: Trichoderma sp. T24, Trichoderma zelobreve T26, Trichoderma longibrachiatum T44, T. zelobreve T53, and Trichoderma sp. T55. Except for strain T44, all other strains demonstrated effectiveness in biological control of S. sclerotiorum (disease severity index ≤25 %) and plant growth promotion in Phaseolus vulgaris L. cultivation (vigor index ≥268). The volatile organic compounds (VOCs) produced by five Trichoderma spp. strains post-exposure to S. sclerotiorum were analyzed by Gas Chromatography-Mass Spectrometry (GC/MS) were identified, among these VOCs with known antifungal activity, such as β-cedrene (6), β-funebrene (7), and α-acoradiene (12). Trichoderma sp. T24, T. zelobreve T53, and Trichoderma sp. T55 have potential as biocontrol agents against S. sclerotiorum and as biostimulants, increasing plant growth and development.