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

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.

Cellulase–lactic acid bacteria synergy action regulates silage fermentation of woody plant

“…These cellulases decompose plant cell walls such that cellular contents are released, thereby reducing the fibre content of forage material. In addition, cellulase can degrade the carbohydrates in material into monosaccharides or disaccharides [ 57 ]. In this study, the epiphytic LAB counts and WSC content in mulberry were low, which led to low-quality natural silage fermentation.…”

Application of Atmospheric and Room-Temperature Plasma (ARTP) to Microbial Breeding

“…High-yield mutants U1, A6, and UA13 exhibited impressive productivity enhancements [ 88 ]. Furthermore, ARTP has been successfully utilized for the production of diverse bioenzymes, including tannase [ 89 , 90 ], raw starch-degrading enzymes [ 91 ], thermostable xylanase [ 92 ], cellulose [ 93 , 94 ] and L-asparaginase [ 95 ].…”

Contribution of Enzyme Catalysis to the Achievement of the United Nations’ Sustainable Development Goals

“…Use of enzymatic fuel cells to generate electrical energy [12,13] Improved production of biofuels through saccharification of non-food biomass [14,15] SDG 8: decent work and economic growth…”