The activities of the extracellular vesicle fractions of these two organisms were compared. Lytic activity against a native type I placental collagen substrate at 30 degrees C was assessed following sodium dodecyl sulphate-polyacrylamide gel electrophoresis and densitometry. A rapid rate of collagen depolymerization was achieved by the extracellular vesicle fraction of W50, yielding approx. 90% substrate degradation compared to 5% for W50/BE1 extracellular vesicles over 6 h incubation. The polypeptide digestion patterns produced by incubation with extracellular vesicle fractions of both organisms were identical, and similar to those yielded by incubation of substrate with whole W50 cells.