Extracellular proteolytic activity of bacteria from soda-salt lakes of Transbaikalia

Influence of nitrogen source on proteinases synthesis in aerobic alkalotolerant and halotolerant bacteria from soda-salt lakes of Transbaikalia was studied. Maximal accumulation of proteinases was revealed on medium with peptones. Introduction of various sources of nitrogen in the medium did not result in increase of enzyme activity in cultural liquid. It was indicated that secreting proteinases of the studied bacteria strains possess narrow substrate specificity, hydrolyze proteins and n-nitroanilide substrates have maximal activity during GlpAALpNA hydrolysis. Data of inhibitory analysis and substrate specificity of studied extracellular enzymes indicate that they belong to a class of serine proteinases of subtilisin-like type.