Biobased lignin-blockers enable efficient production of glucose from lignocelluloses

Enzymatic hydrolysis of cellulose in lignocelluloses exhibits low efficiency due to low cellulose accessibility and adverse lignin effects. By using phenylsulfonic acid pretreatment to improve cellulose accessibility, we have developed several new plant proteins such as corn germ and green rapeseed proteins that extracted from inexpensive defatted meals as lignin-blockers. For pretreated lignocellulosic substrates with high cellulose accessibility, such plant proteins could effectively overcome negative lignin effects and achieve robust cellulose enzymatic conversion (88–97 %) at a low cellulase loading of 5 FPU/g glucan. To reach the same level of cellulose enzymatic conversion, adding corn germ protein could save cellulase loading by 3.6 times as compared to those without lignin-blockers. But these plant proteins showed insignificant promotion effects on substrates with low cellulose accessibility. Overall, this study coupled high cellulose-accessible substrates and efficient lignin-blockers to synergistically improve the profitability of lignocellulosic biorefinery.