Lignin plays a key role in determining biomass recalcitrance in forage grasses. (March 2020) - Oliveira, Dyoni M.
Abstract: Lignocellulosic biomass is an abundant renewable feedstock, rich in polysaccharides that are covalently linked with lignin. In this study, biomass composition of nine forage grasses revealed the role of lignin in biomass recalcitrance. We determined the profiles of cell wall-bound phenolics, lignin, monosaccharides, enzymatic saccharification, and the chemical fingerprints using Fourier transform infrared (FTIR) and Raman spectroscopies. Coastcross and Tifton 85, both bermuda grass cultivars, showed lower lignin content and higher saccharification at 2 h and 72 h of enzymatic hydrolysis, supporting their use as valuable sources of carbohydrates for ethanol production. Principal component analysis (PCA) of thirteen different cell wall traits revealed that lignin was a hierarchical factor in reduced saccharification of forage grasses. As such, lignin content could be used as a marker for the selection of grass cultivars for genetic engineering programs for improved sustainable biofuel production. Highlights: Critical assessment comparing various forage grasses for biomass valorization. Lignin plays a hierarchical role in reducing saccharification of grasses. Lignin content is a good biomarker for the selection of grass cultivars. Alkaline pretreatment strongly enhances lignocellulose saccharification.