Dual strategy for bioconversion of elephant grass biomass into fermentable sugars using Trichoderma reesei towards bioethanol production

Abstract

In this study, biodelignification and enzymatic hydrolysis of elephant grass were performed by recombinant and native strain of Trichoderma reesei, respectively. Initially, rT. reesei displaying Lip8H and MnP1 gene was used for biodelignification with NiO nanoparticles. Saccharification was performed by combining hydrolytic enzyme produced with NiO nanoparticles. Elephant grass hydrolysate was used for bioethanol production using Kluyveromyces marxianus. Maximum lignolytic enzyme production was obtained with 15 µg/L of NiO nanoparticles and initial pH of 5 at 32 °C. Subsequently, about 54% of lignin degradation was achieved after 192 h. Hydrolytic enzymes showed elevated enzyme activity and resulted in 84.52 ± 3.5 g/L of total reducing sugar at 15 µg/mL NiO NPs. About 14.65 ± 1.75 g/L of ethanol was produced using K. marxianus after 24 h. Thus, dual strategy employed for conversion of elephant grass biomass into fermentable sugar and subsequent biofuel production could become potential platform for commercialization.