Lactobacillus rhamnosus R-2002 strain isolated from Armenian pickled cheese sample has a fungicide effect, which was carried out by the first-time designed method. The fungicide effect of LAB strain was expressed after 5 days of co-cultivation with Mucor plumbeus and 6 days of co-cultivation with Penicillium aurantioviolaceum. The growth as well as the antifungal activity of L. rhamnosus R-2002 was shown to directly depend on the nature of the medium's carbon source. The antifungal activity of this strain against both moulds was inhibited when the combination of 10 g l-1 glucose and 10 ml l-1 ethanol in the medium was used as a carbon source. The results could be applied in food industry, medicine, and veterinary.