Carnobacterium

Carnobacterium is a genus of Gram-positive, non-spore-forming lactic acid bacteria in the family Carnobacteriaceae. Members are typically facultatively anaerobic or microaerophilic rods or coccobacilli that ferment carbohydrates to lactic acid. Many species are psychrotolerant, capable of growth at refrigeration temperatures, and they are commonly found in cold environments and food matrices.

Ecology and significance: Carnobacterium species occur in meat, poultry, fish, dairy, and aquatic environments. They are frequently isolated from refrigerated and vacuum-packed foods and can contribute to spoilage under some conditions, though some strains are used as protective cultures due to bacteriocin production. Notable bacteriocins include carnobacteriocins and piscicocins, which can inhibit Listeria monocytogenes and other pathogens.

Genomics and metabolism: They are salt-tolerant and can participate in mixed-species fermentations; metabolism yields mainly lactic acid with variable amounts of acetate, formate, and other metabolites depending on species and conditions.

Applications and safety: Several strains, particularly Carnobacterium maltaromaticum and Carnobacterium piscicola, are studied for biopreservation in seafood and ready-to-eat meats. Human infections are rare and typically occur as opportunistic infections in immunocompromised individuals; in aquaculture, some species can be pathogenic to fish. Overall, many strains are regarded as safe for use in controlled food applications.

Taxonomy: The genus is named for its association with meat (“carn-” flesh) and bacteria; it belongs to Carnobacteriaceae, order Lactobacillales, phylum Firmicutes.