Biological pretreatment of wheat straw using Trametes versicolor for enhanced cellulase production in solid-state fermentation.

Wheat straw is a renewable biomass with potential for bioethanol and biorefinery applications, offering potential value-added products such as enzymes and oligosaccharides. However, its complex lignocellulosic structure, costly pretreatment requirements, and formation of inhibitory compounds hinder its utilization. Moreover, commercial enzymes used in saccharification are expensive, highlighting the need for efficient in-house enzyme production. This study investigates the application of a biological pretreatment using Trametes versicolor as an eco-friendly and cost-effective method to enhance cellulose content in wheat straw. The pretreated biomass was analyzed via acid hydrolysis and employed as a substrate for cellulase production by Penicillium chrysogenum through solid-state fermentation (SSF). The liquid extract obtained after washing the biomass was evaluated for laccase and manganese peroxidase (MnP) activities. In addition, acid hydrolysis was performed to detect oligosaccharides. Biological pretreatment increased cellulose content from 36.24 ± 1.74 to 41.25 ± 1.65% and reduced lignin from 28.66 ± 1.08 to 21.12 ± 1.22%, confirming effective delignification. The pretreated straw supported cellulase production with activities of 2.66 ± 0.044 U/g (FPU), 20.77 ± 1.91 U/g (BGL), and 75.02 ± 2.48 U/g (CMC). Also, xylooligosaccharides reached 1.15 ± 0.06 g/L on day 21. These results demonstrate the potential of combining biological pretreatment and SSF as a sustainable approach to enhance enzyme yields and recover oligosaccharides for biorefinery applications.