Enhancement of bacteriocin production by Carnobacterium divergens AS7 in the presence of a bacteriocin-sensitive strain Carnobacterium piscicola.

The effect of Carnobacterium piscicola in the growth medium of Carnobacterium divergens on divercin production was studied. C. piscicola cultures were added in the form of living cultures, thermally inactivated cultures and pretreated autolyzed cultures. Each form was applied as whole culture comprising growth medium with cells, culture supernatants and cell pellets. It was found that the divercin-sensitive bacterium enhanced significantly the divercin production by C. divergens. The highest stimulating effect was shown by C. piscicola culture autoclaved at 121 degrees C. It enhanced the divercin activity about 64-times compared to the control. The nonautolyzed cultures stimulated divercin biosynthesis to a greater extent than autolyzed cultures, independent of the culture pretreatment. The form of addition was the main external factor affecting divercin production. The possible biochemical mechanisms involved in this enhancement of production are examined.