Bacteria of the species Lactobacillus fermentum with the capacity of inhibiting the development of the fungus Penicillium solitum Deposited with the dsm32093 Identification Number, or the development of the fungus Penicillium brevicompactum Deposited with the Identification Number dsm32094 in at least 5 0%.The Inhibitory activity can be determined in a trial that includes: (1) the preparation of a Fermented dairy product by: (a) inoculation of milk with Lactobacillus fermentum in a concentration of at least 10\u2077 CFU \/ G and with a Starter Culture, fermentation, (b) to achieve a pH 4.6.And (c) solidification of fermented Milk with the addition of agar (2) the generation of at least one point solitum or P. P.Brevicompactum in Fermented Milk solidified with Agar with a concentration of 500 SPOREs by stain, and Incubation for 7 days at a temperature of 25C (3) the determination of the percentage of inhibition by determination of the larger diameter of the Colony formed P Or the development of solitum or P. P.Brevicompactum and the expression of the diameter and the percentage of the largest diameter formed under the same conditions but in the absence of the strain of Lactobacillus fermentum. Compositions comprising bacteria, Methods for the production of fermented Milk Products by using the bacteria, and the products obtained in this way.Una bacteria de la especie Lactobacillus fermentum con la capacidad de inhibir el desarrollo del hongo Penicillium solitum depositado con el número de identificación DSM32093, o el desarrollo del hongo Penicillium brevicompactum depositado con el número de identificación DSM32094, en al menos 50%. La actividad inhibitoria puede ser determinada en un ensayo que comprende: (1) la preparación de un producto lácteo fermentado por: (a) inoculación de leche con Lactobacillus fermentum en una concentración de al menos 10⁷ UFC/g y con un cultivo iniciador, (b) fermentación hasta lograr un pH de 4,6, y (c) solidificación de la leche ferment
