(660d) Modulation of Lignin Inhibition on Lignocellulose Hydrolysis

Authors: 
dos Santos, A. C. F., Purdue University
Ximenes, E., Purdue University
Mosier, N. S., Purdue University
Ladisch, M. R., Purdue University
Lignin negative impact on hydrolysis of sugarcane was reduced while maintaining efficient conversion through modulation of the liquid hot water pretreatment. A decrease in production costs require that enzyme costs be reduced. This is achieved by reducing protein loadings during the hydrolysis of lignocellulose. The addition of non-catalytic proteins has been shown to reduce lignin adsorption of cellulases and reduce the amount of the enzymes necessary. However, these proteins also incur costs albeit less than active enzymes. In this work, an alternative method to reduce lignin adsorption and protein loadings was investigated. The processes were evaluated based on relative conversion of cellulose to glucose and the improvement to it with the addition of inert protein. By controlling the pretreatment severity, through temperature and time, an optimal pretreatment condition was identified. Liquid hot water pretreatment conducted at 200°C for 20 minutes, reduced the lignin impact on final conversion to negligible. This effect was observed across different enzyme products at low protein loadings. Across literature data, a relationship between lignin content and inert protein addition can be observed. The effect of lignin adsorption is highly dependent on pretreatment method and enzyme product used. Despite this limitation, the negative impact of lignin can be predicted. This work demonstrates that optimal processing can reduce enzyme loadings towards a more efficient hydrolysis process.