Graphene oxide mediated enhanced cellulase production using pomegranate waste following co-cultured condition with improved pH and thermal stability

Abstract

High production cost of cellulase enzyme is one of the major hurdles in economic biomass to biofuel production process at industrial scale. In this context, development of advanced approaches to produce low-cost commercial cellulase is highly demanding. Therefore, in the present study, simultaneous effect of pomegranate waste (PW) and graphene oxide (GO) has been studied to improve the cellulase production along with improved stability towards the incubation temperature and different pH environment. Crude cellulase production has been achieved at high substrate concentration of PW using co-culturing of strains Cladosporium cladosporioides NS2 and Rhizopus oryzae NS5 under the solid-state fermentation (SSF) while using GO as the nanocatalyst. At a substrate concentration of 7.0 g of PW, highest enzymatic activity of 42 IU/gds FP, 271 IU/gds EG and 422 IU/gds BGL have been achieved by mean of 1.5% GO after 72 h. In addition, crude enzyme exhibits 45–55 °C and 3.5–6.5 as the most favorable incubation temperature and pH range, respectively in presence of 1.5% GO. This study reports a potential strategy to improve the production of crude enzyme along with enhanced thermal and pH stability with the implementation of GO as a nanocatalyst. Thus, the present approach offers a sustainable way to produce crude enzyme that can have numerous industrial applications along with economic biomass to biofuels production technology by providing easy, as well as high yield of sugar production via enzymatic hydrolysis of cellulosic biomass. Nevertheless, recycling of GO when employed as catalyst during the entire process remains to be challenging, and therefore efforts should made to overcome this issue.