In studies on digestive processes and microorganisms in the gut of the
common woodlouse, Porcellio scaber (Isopoda: Oniscidea), we observed
marked contradictions between the activity of cellulolytic enzymes and
the number of microorganisms. The anterior hindgut exhibited the high
est cellulolytic activity, but was characterized by low microbial coun
ts. Due to the presence of endosymbiotic bacteria in the midgut lobes
that appear to produce cellulases, we suggest that the cellulases that
are active in the hindgut of woodlice are of endogenous origin.