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

Autor: Raja Mohan Gopalakrishnan, Tamilvendan Manavalan, Janani Ramesh, Kalaichelvan Puthupalayam Thangavelu, Klaus Heese
Jazyk: angličtina
Rok vydání: 2020
Předmět:
Zdroj: Microorganisms, Vol 8, Iss 2, p 159 (2020)
Druh dokumentu: article
ISSN: 2076-2607
DOI: 10.3390/microorganisms8020159
Popis: 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.
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