The Lactobacillus curvatus straindeposited as DSM18775 is used as a biopreservative culture in a wide range of meat products due to its production of bacteriocin. The present invention relates to Lactobacillus curvatus strains having an extended lag phase of at least 24 hours at 30°C relative to DSM18775. In a presently preferred embodiment, the strains are mutants of DSM18775, such as the Lactobacillus curvatus strain deposited as DSM32590 and the Lactobacillus curvatus strain deposited as DSM 32591. Further, the invention relates to a method for inhibiting Listeria in a food product comprising adding bacteria of a Lactobacillus curvatus strain according to the invention to a food product in a concentration of at least 105 CFU/g.