Regulation of cellvibriocin activity.

Attempts were made to enhance the production of cellvibriocin, the bacteriocin produced by Cellvibrio sp. NCIB 9916, by a study of cultural conditions in agar (solid) media. In such media cellvibriocin was unstable: within 24 h all activity disappeared at 45 degrees C, 70% at 37 degrees C and more than 50% within 5 days at 5 degrees C. The temperature at which the producer strain was grown was critical, 25 degrees C being optimal. Cellvibriocin activity was markedly affected by the composition of the medium. Small amounts of metallic salts (Cu2+, Mn2+, Sr2+, Zn2+) and carboxylic acids of the citric acid cycle, especially citrate and tartrate, promoted its activity. Protease inhibitors, p-chloromercuribenzoic acid, N-ethyl maleimide and iodoacetate, enhanced cellvibriocin activity whereas a promoter of protease activity, casein hydrolysate, decreased activity.