The present invention relates to a bacterium of the species Lactobacillus fermentum having the ability to inhibit the growth of the fungus Penicillium solitum deposited under the accession No.: DSM32093 or the growth of the fungus Penicillium brevicompactum deposited under the accession No.: DSM32094 by at least 50%. The inhibitory activity can be determined in an assay comprising: (1) preparing a fermented milk product by: (a) inoculating a milk with the Lactobacillus fermentum in a concentration of at least 107 CFU/g and with a starter culture, (b) fermenting until a p H of 4.6 is reached, and (c) solidifying the fermented milk by the addition of agar (2) generating at least one spot of the P. solitum or the P. brevicompactum on the agar solidified fermented milk with a concentration of 500 spores/spot and incubating the 1 same for 7 days at 25 °C (3) determining the percent inhibition by determining the largest diameter of the colony formed by growth of the P. solitum or P. brevicompactum and expressing the diameter as percent of the largest diameter formed under the same conditions but in the absence of the Lactobacillus fermentum strain. The invention further relates to compositions comprising the bacterium, methods for producing fermented milk products using the bacterium and the products thus obtained.La présente invention concerne une bactérie de lespèce Lactobacillus fermentum ayant la capacité dinhiber la croissance du champignon Penicillium solitum déposé sous le n° dordre: DSM32093 ou la croissance du champignon Penicillium brevicompactum déposé sous le n° dordre: DSM32094 dau moins 50 %. Lactivité inhibitrice peut être déterminée dans un dosage consistant à : (1) préparer un produit laitier fermenté par : (a) une étape dinoculation dun lait avec la bactérie Lactobacillus fermentum à une concentration dau moins 107 CFU/g et avec une culture starter, (b) une étape de fermentation jusquà ce quun pH de 4,6 soit atteint, et (c) une étape de solidification
