Abstract

The proteolytic activity produced by a strain of Proteus vulgaris isolated in this laboratory from a staling hide exhibiting depilation was studied. The P. vulgaris bacterium apparently produced a single protease or protease complex according to ion exchange and gel exclusion chromatography. The protease had maximal proteolytic activity in the 8.0-9.0 pH unit range and was quite stable at high salinities (1.0 M). The protease was heat labile being increasingly inactivated when exposed to temperatures above 30°C; the inclusion of divalent calcium ions failed to significantly thermostabilise the protease. The protease had a molecular mass of 44000 daltons.