Alkaline Pretreatments for Sorghum and Miscanthus Anaerobic Digestion: Impacts at Cell Wall and Tissue Scales

Lignocellulosic biomass is hardly degraded during anaerobic digestion. Among a large panel of pretreatments used to improve the biodegradability this substrate, alkaline are recognized as most efficient remove lignin and therefore methane production these substrates. This article uses different histological stains (FASGA, phloroglucinol, Mäule reagent, Congo red), immunolocalization, quantification on pretreated internode stem tissue section in order decipher mechanism pretreatment action (CaO NaOH) anatomical lignocellulosic matrix scale Sorghum Biomass 140 hybrid Miscanthus × giganteus Floridulus. A significant delignification all tissues was observed (sclerenchyma, parenchyma, xylem) except epidermis internal part perivascular sclerenchyma. The degradation under effect accompanied by massive unmasking cellulose reduction crystalline cellulose. induced an increase digestion kinetics for both yield miscanthus. rich G-type lignins located mainly at level sclerenchyma external zone which more alkalies than S-type lignin; may explain improvement miscanthus potential.