Control of mould growth by Lactobacillus rhamnosus VT1 and Lactobacillus reuteri CCM 3625 on milk agar plates

The possibility to control mould growth by Lactobacillus rhamnosus VT1 and Lactobacillus reuteri CCM 3625 in a milk environment was assessed using the milk agar plate method. Higher antifungal activity was exhibited by actively growing cells of both lactobacilli strains compared with the MRS broth supernatants of both bacterial strains containing metabolites with antifungal activity. The control of mould growth by Lactobacillus reuteri CCM 3625 was proved to be associated with the production of the mixture of lactic (0.9 % w/w), acetic (0.2 % w/w), and succinic (0.2 % w/w) acids. The mechanism of mould growth control by Lactobacillus rhamnosus VT1 probably consists in the production of lactic acid (1.2 % w/w) together with some other metabolite(s) of non-proteinaceous and non-saccharidic nature with antifungal activity.