Biological activities of partially purified elastase produced by Flavobacterium meningosepticum.

Injection of viable cells of Flavobacterium meningosepticum at doses of 10(6) colony-forming units/eye caused ophthalmia in rabbits' corneas. Elastase, free of protease activity, was partially purified from broth cultures of F. meningosepticum ATCC12535 and TMS516. The optimum pH of the elastase activity was about 8.0. The activity was suppressed by Ni, Zn, Co, EDTA, and o-phenanthroline, and accelerated by Cu and Fe. The minimum dose of the elastase causing ophthalmia in the eyes of rabbits was 5 micrograms/eye (0.065 elastase units). The minimum lethal dose of the elastase for suckling mice by intracerebral injection was 0.4 micrograms (0.0052 elastase units)/suckling mouse, and its minimum lethal dose for adult mice by intraperitoneal injection was 740 micrograms/mouse (9.52 elastase units).