PROTEASE PRODUCTION BY STREPTOMYCES-THERMOVULGARIS GROWN ON RAPEMEAL-DERIVED MEDIA

A range of actinomycete species was tested for their ability to grow o n particulate and particle-free rapeseed meal-derived media. Streptomy cetes grew on both types of medium and produced a number of extracellu lar enzymes. Highest activities of protease were produced by Streptomy ces thermovulgaris and reflected the high available protein content of rapemeal. Enzyme production and growth were analysed in fermenter-gro wn batch cultures of S. thermovulgaris using the particle-free rapemea l broth termed medium B. Growth was biphasic and the majority of the p rotease was produced during the second slower phase. Analysis of the p rotease as azocaseinase activity revealed a high degree of thermostabi lity in the presence of calcium such that approximately 20% of the act ivity remained after incubation at 70 degrees C for 24 h. Gel filtrati on suggested that S. thermovulgaris synthesized more than one kind of protease and this was confirmed by using specific peptide substrates a nd inhibitors which revealed the presence of distinct serine and metal lo-type enzymes.