THE EFFECT OF CARBON, NITROGEN SOURCES AND NaCl ON THE GROWTH AND BIOSYNTHESIS BACTERIOCINS OF LACTOCOCCUS STRAINS PD14, PD2.9 AND BV20

Abstract

Bacteriocin production has been affected by a number of factors including media composition, such as carbon, nitrogen sources, NaCland fermentation conditions. Bacteriocins synthesized by  Lactococcus  strains PD14, BV20, PD2.9 inhibit the growth of some lactic acid bacteria and especially  Staphylococcus aureus, Bacillus subtilis.  Optimal production of bacteriocin PD14 (795 AU/ml) was recorded in MRS broth with an initial sucrose of 25 g/l, 0.1% (NH₄)₂HPO₄ as sole nitrogen source. Bacteriocin PD2.9 was produced in MRS broth with 15 g/l sucrose and was supplemented with (NH₄)₂HPO₄, NH₄H₂PO₄. Bacteriocin BV20 produced in MRS broth when glucose was replaced with 20 g/l sucrose. Bacteriocin BV20 production, on the other hand, was more influenced by nitrogen content, but increased to 795 AU/ml when glucose was replaced with sucrose, or when MRS broth was supplemented four salts as NH₄NO₃,(NH₄)₂HPO₄, NH₄H₂PO₄, NH₄Cl.