Isolation and characteristics of Bacillus subtills CN2 and its collagenase production

An isolated bacterium strain named CN2 found in Vietnamese fish sauce has been identified as Bacillus subtilis. In an enzyme- producing medium with 0% and 8% NaCl concentration, the CN2 strain produced the maximum collagenase activity, 3.07 U/ml and 2.60 U/ml. The strain also produced gelatinase, but the maximum activity was only 1.03 U/mI at 8 h of Incubation time and prolonged more than 22 h. Bacillus subtilis CN2, grown slowly in a medium containing 12% NaCl, showed a decreased rate of collagenase activity with a maximum activity of 1.60 U/ml at 18 h of incubation time. The culture supernatant of CN2 strain digested a purified native collagen from rat tail tendon as well as as-casein at Met(123)-Lys(124) position. Therefore The culture supernatant of CN2 can be used to produce healthy foods.