Nisin production process

A process of producing a nisin-containing lactate ferment, comprising the consecutive steps of:

• (a) inoculating a nutrient medium comprising a solution of a fermentable substrate and a nitrogen source in an aqueous medium with nisin producing lactic acid bacteria;
• and
• (b) incubating the inoculated nutrient medium under conditions favorable to the growth and/or metabolic activity of said lactic acid bacteria for a period sufficient to produce a fermentation broth containing at least 20 g/l of lactate equivalents and/or at least 1000 TU/ml of nisin equivalent activity, during which period the pH of the fermentation broth is controlled by addition of one or more alkalization agents comprising sodium hydroxide and calcium hydroxide, wherein the Na:Ca (w/w) ratio of the added hydroxides is between ⅙ 1/1,
• wherein the pH of the fermentation broth is maintained between 5.0 to 6.0 in step (b);
• and
• (c) evaporating substantially all water from the ferment to obtain a free flowing powder containing anhydrous calcium lactate in combination with sodium lactate as the bulk of the powder.