Cellulase production and efficient saccharification of biomass by a new mutant Trichoderma afroharzianum MEA-12

Biotechnology for Biofuels

Xian-Hai Zeng¹  Sheng-Shan Wu¹  Shu-Liang Yang¹  Yi Lin¹  Zhi-Qing Peng¹  Lu Lin¹  Jian Liu¹  Chuang Li¹  Li-Hui Gan¹ 

[1] College of Energy, Xiamen University;

关键词: Trichoderma afroharzianum;    Compound mutagenesis;    Adaptive laboratory evolution;    Cellulase;    Biomass;   

DOI  :  10.1186/s13068-021-02072-z

来源: DOAJ

【 摘 要 】

Abstract Background Cellulase plays a key role in converting cellulosic biomass into fermentable sugar to produce chemicals and fuels, which is generally produced by filamentous fungi. However, most of the filamentous fungi obtained by natural breeding have low secretory capacity in cellulase production, which are far from meeting the requirements of industrial production. Random mutagenesis combined with adaptive laboratory evolution (ALE) strategy is an effective method to increase the production of fungal enzymes. Results This study obtained a mutant of Trichoderma afroharzianum by exposures to N-methyl-N’-nitro-N-nitrosoguanidine (MNNG), Ethyl Methanesulfonate (EMS), Atmospheric and Room Temperature Plasma (ARTP) and ALE with high sugar stress. The T. afroharzianum mutant MEA-12 produced 0.60, 5.47, 0.31 and 2.17 IU/mL FPase, CMCase, pNPCase and pNPGase, respectively. These levels were 4.33, 6.37, 4.92 and 4.15 times higher than those of the parental strain, respectively. Also, it was found that T. afroharzianum had the same carbon catabolite repression (CCR) effect as other Trichoderma in liquid submerged fermentation. In contrast, the mutant MEA-12 can tolerate the inhibition of glucose (up to 20 mM) without affecting enzyme production under inducing conditions. Interestingly, crude enzyme from MEA-12 showed high enzymatic hydrolysis efficiency against three different biomasses (cornstalk, bamboo and reed), when combined with cellulase from T. reesei Rut-C30. In addition, the factors that improved cellulase production by MEA-12 were clarified. Conclusions Overall, compound mutagenesis combined with ALE effectively increased the production of fungal cellulase. A super-producing mutant MEA-12 was obtained, and its cellulase could hydrolyze common biomasses efficiently, in combination with enzymes derived from model strain T. reesei, which provides a new choice for processing of bioresources in the future.

【 授权许可】

Unknown