Abstract

OPTIMAZATION OF PROTEASE PRODUCED FROM CRONOBACTER SAKAZAKII R4

Nedhaal S. Zbar, Rusul Raad Hwydii*, Hameed M. Jasim and Nedhaal

ABSTRACT

Cronobacter sakazakii was supplied from biotechnology department/college of science primarily identified according to their cultural and morphological tests and biochemical characteristics. The ability of these isolates in protease production was examined. Results showed that all five isolates of C.sakazakii were protease producers with variable degrees. Among them, the isolate symbold C.sakazakii R4 was the most efficient in protease production. The specific activity of protease produced in crude filtrate was 35.8 U/mg protein. Upon that, this isolate was selected to determine optimum conditions for protease production. Results showed that maximum protease production was achieved after supplementation of the production medium (pH7) with 0.5% glucose, 1.5% tryptone and 0.1% KH2Po4 and inoculation with 104 CFU /ml of fresh bacterial culture and incubated at 30 ̊C in shaker incubator (150 rpm) for 24h. Under these conditions, the specific activity of protease produced in culture medium was sharply increased to 80.4U/mg protein.

Keywords: Cronobacter sakazakii C.sakazakii symbol 80.4U/mg protein.