Improvement of Saccharification and Delignification Efficiency of Trichoderma reesei Rut-C30 by Genetic Bioengineering

Abstract

Trichoderma reesei produces various saccharification enzymes required for biomass degradation. However, the lack of an effective lignin-degrading enzyme system reduces the species’ efficiency in producing fermentable sugars and increases the pre-treatment costs for biofuel production. In this study, we heterologously expressed the Ganoderma lucidum RMK1 versatile peroxidase gene (vp1) in the Rut-C30 strain of T. reesei. The expression of purified 6×His-tag–containing recombinant G. lucidum-derived protein (rVP1) was confirmed through western blot, which exhibited a single band with a relative molecular weight of 39 kDa. In saccharification and delignification studies using rice straw, the transformant (tVP7, T. reesei Rut-C30 expressing G. lucidum-derived rVP1) showed significant improvement in the yield of total reducing sugar and delignification, compared with that of the parent T. reesei Rut-C30 strain. Scanning electron microscopy (SEM) of tVP7-treated paddy straw showed extensive degradation of several layers of its surface compared with the parent strain due to the presence of G. lucidum-derived rVP1. Our results suggest that the expression of ligninolytic enzymes in cellulase hyperproducing systems helps to integrate the pre-treatment and saccharification steps that may ultimately reduce the costs of bioethanol production.

Identification of a Novel Thermostable Alkaline Protease from Bacillus megaterium-TK1 for the Detergent and Leather Industry

“…Standard SDS-PAGE procedures were performed to determine the molecular weight (MW) of the purified protease [ 16 , 17 ]. Zymography was performed as described by Rajkumar et al [ 9 ].…”

Identification of Cellulose-Degrading Bacteria and Assessment of Their Potential Value for the Production of Bioethanol from Coconut Oil Cake Waste

“…FESEM was used to evaluate the microstructural changes of COC before and after bacterial treatment. Briefly, representative micrographs of the samples were taken at 5 kV using a S-4800 FESEM (Thermo Scientific, Waltham, MA, USA) [ 21 ].…”

Enhanced biodegradation of organic waste treated by environmental fungal isolates with higher cellulolytic potential

“…is inefficient for lignin degradation, and here, the ligninolytic activity of T. reesei M168 was not detectable in the enzyme hydrolysate. Genetic bioengineering has been used to transform the T. reesei Rut C30 for the improved delignification of rice straw [50].…”