Effect of Cameline Nisin isolated from Lactococcus lactis sub sp. lactis on Staphylococcus aureus sp.

The camel milk differs from milk of other species by the presence of a powerful protector system, linked to relatively high levels of lysozyme, lactoperoxidase, lactoferrin, component-3 of proteose peptone (PP3), organic acid, hydrogen peroxide and bacteriocins produced by lactic acid bacteria. The study aims to estimate the part of a bacteriocin (type nisin) produced by a strain of Lactococcus lactis sub sp lactis isolated from camel milk, in this protective system and its antibacterial activity against a strain of Staphylococcus aureus isolated from a bovine milk sample. Optimize conditions for a nisin production, by the producing strain isolated and purified, was carried out, by glucose addition (1%) to the M17 medium. Antagonism tests by the disk method showed inhibition zones (IZ Ø) from 6 to 8mm in diameter depending on the incubation time of the producing strain. Thus, for incubation periods of 18h, the production of camel nisin appeared to be maximum (IZ= Ø 8mm) with a minimum growth of Lactococcus lactis sub sp lactis (pH 6, 37). Optimum growth of camel Lactococcus lactis sub sp lactis strain (pH 6.17) and an optimum production of nisin (IZ= Ø 8mm) were registered for a 24 hours incubation period.