The present invention relates to novel strains of Lactobacillus as well as preparations and compositions, such as fermentation broths, protective cultures, final food or feed product with Lactobacillus alone or in combination with bacteria of the genus Propionibacterium. The present invention further relates to methods for the controlling of growth of a contaminant, such as a bacteria, yeast or mould by using these novel strains of Lactobacillus.