Enhancing Methane Production from Empty Fruit Bunches by Augmented Thermoanaerobacterium thermosaccharolyticum PSU-2

The recalcitrant nature of the substrate often limits the anaerobic digestion of Empty Fruit Bunches (EFB). This study investigates the effectiveness of augmenting Thermoanaerobacterium thermosaccharolyticum PSU-2 for the pretreatment of EFB in mono-digestion and co-digestion with Palm Oil Mill Effluent (POME) to enhance biogas production. The augmented T. thermosaccharolyticum PSU-2 demonstrated enhanced cellulolytic and hemicellulolytic capabilities, resulting in improved biogas yield, methane content, and substrate degradation efficiency compared to the control without augmentation. Mono-digestion of EFB with the augmented strain at an S:I ratio of 15:1 achieved a methane yield of 35.13 ± 1.05 m³ CH₄/tonne, representing a 64.31 ± 1.17% improvement over the control. Co-digestion of EFB with POME using the augmented strain further enhanced the methane yield to 46.67 ± 1.40 m³ CH₄/tonne at an S:I ratio of 15:1, representing a 103.00 ± 2.81% improvement over the control. Kinetic analysis revealed improved hydrolysis rates and reduced lag phases in mono-digestion and co-digestion processes. Comparison with other pretreatment methods and energy balance and economic analysis indicated that co-digestion of EFB with POME using the augmented T. thermosaccharolyticum PSU-2 pretreatment is a promising, energy-efficient, and profitable approach for enhancing biogas production from EFB. This study highlights the potential of biological pretreatment using augmented bacterial strains to improve the valorization of agricultural waste streams through anaerobic digestion.