Extracellular proteinase and lipase activity of Flavobacterium MTR3

Flavobacterium MTR3 by culturing in skim milk produced significant proteina se but limited lipase activity. Proteinase activity at 25 and 5 degrees C w as observed during idiophase, when bacterial counts were 10(7)-10(8) cfu/ml . Proteinase production was higher in agitated cultures and it was not affe cted by iron addition. Lipase production was not stimulated by culture agit ation or iron addition. Addition of ascorbic acid limited maximum bacterial counts and enzyme production. Extracellular proteinase preparation from Fl. MTR3 was heat labile and was not stabilised by calcium. It exhibited maximum activity at 37-45 degrees C and in alkaline pH region. Kinetic parameters, K-m and V-max values, were estimated 0.06 mM and 32.3 units/.g protein respectively, using casein as s ubstrate. It hydrolysed faster beta- than alpha-casein, and cow's than ewe' s milk caseins. Proteinase studied exhibited leucine aminopeptidase activit y, but casein peptide hydrolysis was low.