Exploring the termite gut as a hub of industrially important microbes and enzymes for biofuel production

Termites harbour a diverse array of microsymbionts in their gut and their remarkable ability to hydrolyse lignocellulosic biomass into fermentable sugars has been a subject of interest in biofuel research. By producing lignocellulolytic enzymes, microsymbionts in the termite gut can depolymerise 74–99 % of cellulose and 65–87 % of hemicelluloses within hours, thus opening new vistas in sustainable biomass saccharification, especially for bioenergy purposes. Interestingly, some termite gut microsymbionts are also capable of fermenting the hydrolysed sugars into biofuels or other energy-rich intermediates, thus presenting a strong case for nature-inspired product development. Hence, this review aims to unravel the biotechnological potential of the termite gut as an untapped habitat for novel hydrolytic enzymes and a hub for biofuel-producing microsymbionts. In this regard, the diversity and versatility of the termite gut metagenome were explored to identify microsymbionts responsible for producing lignocellulolytic enzymes such as ligninases, xylanases, cellulases as well as accessory enzymes. The saccharification potential of these microsymbionts, which include bacteria, fungi and yeasts-was also critically analysed in this study. Lastly, this review delved into the different classes of biofuels that can be directly or indirectly produced by termite gut microsymbionts from the saccharified biomass. Bioprospecting for novel lignocellulolytic and biofuel-producing termite gut microsymbionts is a potential route towards achieving global sustainable energy production. • Diverse microsymbionts inhabit the termite gut. • Microsymbiont enzymes contribute to the efficient hydrolysis of biomass in termite guts. • Termite gut microsymbionts are capable of fermenting biomass hydrolysates into essential biofuels. • Industrial production of biofuels could be facilitated using termite gut microsymbionts.