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The aim of this work was to study how to minimize cellulase inhibition of whole slurry biomass hydrolysis through addition of carbocation scavengers during acid-catalyzed pretreatment. Various potential carbocation scavengers were compared and their inhibition mitigating effects towards the hydrolytic performance of cellulase enzymes was assessed. The results indicated that the addition of carbocation scavengers during the pretreatment process could not only alleviate the inhibitory effect of the phenolics on the enzymatic hydrolysis but also increase the accessibility of cellulases to the pretreated substrates. It appeared that lignin-derived compounds such as 4-hydroxybenzoic acid, vanillic acid, syringic acid could all serve as efficient scavengers to alleviate the inhibitory effect of phenolics on cellulose hydrolysis where the syringic acid showed the best mitigating effect. By combining the carbocation scavengers in the pretreatment process, an improved cellulose hydrolysis of the pretreated whole slurry could be achieved without any post detoxification step., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

In this study, two selected hardwoods were subjected to sodium chlorite delignification and steam explosion, and the impact of pre-treatments on synergistic enzymatic saccharification evaluated. A cellulolytic core-set, CelMix, and a xylanolytic core-set, XynMix, optimised for glucose and xylose release, respectively, were used to formulate HoloMix cocktail for optimal saccharification of various pre-treated hardwoods. For delignified biomass, the optimized HoloMix consisted of 75%:25% protein dosage, CelMix: XynMix, while for untreated and steam exploded biomass the HoloMix consisted of 93.75%:6.25% protein dosage. Saccharification by HoloMix (27.5mgprotein/gbiomass) for 24h achieved 70-100% sugar yields. Pre-treatment of the hardwoods (especially those with a higher proportion of lignin) with a laccase, improved saccharification by HoloMix. This study provided insights into enzymatic hydrolysis of various pre-treated hardwood substrates and showed the same lignocellulolytic cocktail comparable to/if not better than commercial enzyme preparations can be used to efficiently hydrolyse different hardwood species., (Copyright © 2017 Elsevier Ltd. All rights reserved.)