Optimizing biomethanation of a lignocellulosic biomass using indigenous microbial-cellulases systems

Abstract

Studies on enhancing biomethanation were performed to ascertain whether amending lignocellulosic biomass waste with indigenous microbial-cellulases systems will improve biomethane output. To evaluate this, gastrointestinal contents of slaughtered beef cattle were treated with inocula derived from the guts of giant African land snail (Archachatina marginata) and worker termites (Coptotermes formosanus), individually as well as combined. The fed-batch method operating at prevailing ambient room temperatures (30 ± 2EC) for a hydraulic retention time (HRT) of 60 days was adopted. Feedstock slurry without amendment, amended with Archachatina marginata-derived inoculum, amended with Coptotermes formosanus-derived inoculum, and amended with Archachatina marginata: Coptotermes formosanus (50 : 50%) mixed inocula yielded cumulative biomethane of 65.26 ml/g VS, 63.21 ml/g VS, 125.99 ml/g VS, and 97.16 ml/g VS, respectively. Physicochemical analysis of feedstock and digestates revealed increased reductions in lignin, hemicelluloses, and celluloses (lignocelluloses) in trials amended with microbial-cellulases systems. This study revealed that among the experiments assayed, the trial amended with the cellulases system from Coptotermes formosanus yielded the highest cumulative biomethane.