Proposed mechanism of enzyme transport between shipworms and their bacterial symbionts

Bacterial carbohydrate active enzymes (CAZymes) play an important role in wood digestion in shipworms. The main site of lignocellulose digestion within these wood-boring molluscs is the caecum, which contains both endogenous lignocellulolytic enzymes and prokaryotic enzymes produced by endosymbiotic bacteria resident within specialised shipworm cells called bacteriocytes, located in the animal’s gills. Until now, the mechanism by which bacterial enzymes reach the distant caecum lumen has remained mysterious.