Abstract: The invention relates to a novel microorganism strain Lactobacillus casei ssp. rhamnosus LC-705, DSM 7061, having a yeast and mold controlling effect, to bacterial preparations comprising this strain, alone or in combination with a bacterium of the genus Propionibacterium or another strain of the bacterium Lactobacillus casei and/or with conventional agents used for yeast and mold control. The invention also relates to the use of said strain and said bacterial preparations for yeast and mold control and to a method for controlling the growth of yeasts and molds using a bacterial preparation comprising said strain.