Wheat straw hydrolysis by using co-cultures of Trichoderma reesei and Monascus purpureus toward enhanced biodegradation of the lignocellulosic biomass in bioethanol biorefinery

Wheat straw (Triticum aestivum) is one of the lignocellulosic materials largely available worldwide and could be potentially used for biofuel production. Aiming the cost-effective utilization of wheat straw in the sugar-based biorefineries, co-cultures of Trichoderma reesei and Monascus purpureus were used for the enzymatic hydrolysis of the wheat straw biomass. The enzymatic breakdown of the dual-fungi-treated wheat straw was chemically analyzed through different enzyme/compositional assays, and the structural modifications were studied through scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FTIR). For hydrolytic enzyme assays, the co-culture treatments resulted in significantly higher values (carboxymethyl cellulase (212.3 U/ml; p = 0.0173*), total cellulase (202 U/ml; p < 0.0001****), and xylanase (96.7 U/ml; p < 0.0001****) when compared with the readings of pure cultures. This hydrolytic activity resulted in the enhanced breakdown of wheat straw exhibiting a significant loss of 45.2% in lignin, 19.18% in cellulase, and 21.84% in hemicellulose contents. Furthermore, SEM and FTIR analysis of the co-culture treatments verified the improved biodegradation of wheat straw. Accumulatively, these results suggest a better approach for the effective use of dual-fungi for the lignocellulosic biomass breakdown and may have applications in bioethanol biorefineries using wheat straw as a sugar feedstock.