Impact of delignification on the morphology and the reactivity of steam exploded wheat straw.

International audienceThe purpose of this article was to better understand the role of lignin in the recalcitrance of lignocellulosicbiomass during enzymatic hydrolysis. Steam exploded wheat straw was partially delignified with sodiumchlorite to six different grades of delignification. Delignification did not have a significant impact on theenzymatic hydrolysis of the studied wheat straw in the experimental conditions tested. Inhibitive impactof lignin in terms of non-productive adsorption was then explored using soda lignin from wheat straw andkraft lignin from softwood. The addition of both lignins had a strong negative influence on the hydrolysis of highly crystalline cellulose (Avicel), whereas it impacted only slightly the hydrolysis of delignifiedwheat straw. These results are probably linked to the greater accessibility and surface area of steamexploded wheat straw cellulose, which are much higher than those of the crystalline cellulose Avicel