Enhancing wheat bran deconstruction with enzyme cocktails from Penicillium spp. and Trichoderma harzianum: the impact of β-glucosidase supplementation

Forests and natural environments are valuable sources of organisms capable of degrading plant cell wall carbohydrates. In the present study, two isolates, Penicillium polonicum and Penicillium chrysogenum, obtained from Brazilian Cerrado soil, along with a previously characterized isolate of Trichoderma harzianum, were evaluated for their ability to produce carbohydrate-active enzymes when grown in the presence of wheat bran. P. chrysogenum exhibited higher production of endoglucanases, xylanases, and pectinases. Biochemical characterization showed that most enzymes were active at pH 5 and within a temperature range of 30-50 °C, with the exception of P. chrysogenum endoglucanases, which displayed optimal activity at 60 °C. Hydrolysis of cellulose and carboxymethyl cellulose by the three enzyme sources demonstrated that supplementation with recombinant β-glucosidase from Clostridium thermocellum (BglA) significantly enhanced reducing sugar release; specifically, when applied to P. chrysogenum, the reducing sugar yield from cellulose hydrolysis increased by 2.53-fold. In the hydrolysis of wheat bran, enzymes from P. chrysogenum and T. harzianum supplemented with BglA resulted in a 1.6- and 3.93-fold increase in D-glucose yield, respectively. The results presented in this study contribute to the development of more robust enzyme cocktails for wheat bran valorization.