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