Host-symbiont collaboration in lignocellulose digestion by the termite R. flavipes

In addition to evolving highly social lifestyles, two equally fascinating aspects of termite biology are their reliance on lignocellulose as a sole nutrition source and their mutualistic relationships with gut symbionts for lignocellulose digestion. Termites are also considered excellent model systems for studying the production of bioethanol and renewable bioenergy from 2nd generation (non-food) feedstocks. While gut symbionts were long considered as the sole contributors to termite lignocellulose digestion, in recent years the contributions of the host termite to the digestion process have become increasingly apparent. However, the degree to which (i) host enzymes and (ii) host and symbiont collaborate in lignocellulose digestion remain poorly understood. Most importantly, how host and symbiont enzymes specifically collaborate (i.e., in additive or synergistic ways) is essentially unknown. Here, we undertook translational-genomic studies at the protein level to gain new insights into termite digestion. We used a combination of native gut tissue preparations and recombinant enzymes derived from the host gut transcriptome to idenfity synergistic collaboration between host and symbiont, and among enzymes produced by the host termite. Our findings provide important new evidence of synergistic collaboration among enzymes in release of the fermentable monosaccharide glucose from wood lignocellulose.