Microbial consortium-based strategies for enhanced biogas production from Napier grass: A review

The production of biogas from Napier grass (NG) offers a viable approach for renewable energy production; nonetheless, its lignocellulosic structure, especially the elevated lignin levels, hinders microbial access and conversion efficiency. The role of microbial consortia, syntrophic microbial interactions, bioaugmentation techniques and direct interspecies electron transfer mechanisms in enhancing lignocellulosic biodegradation and CH 4 production has not been thoroughly reviewed, despite the growing body of research on pre-treatment and anaerobic digestion of NG. The focus is on the collaborative interactions between cellulolytic, hemicellulolytic and methanogenic microorganisms that facilitate effective hydrolysis and methanogenesis. The overview covers an analysis of feedstock characteristics, inoculum selection, pre-treatment techniques and engineered consortium design intended to enhance biogas production. Recent advances in metagenomic analysis, bioaugmentation strategies and process optimisation tools such as dynamic fermentation modelling and real-time CH 4 monitoring are highlighted for their significance in comprehending and enhancing digestion dynamics. Additionally, the review examines co-digestion methods, the use of digestate and the development of strong, ready-to-use microbial mixtures appropriate for large-scale implementation. This synthesis of current findings offers valuable insights into the strategic engineering of microbes to address the challenges posed by NG, thereby promoting the advancement of efficient, stable and scalable bioenergy systems.