Latilactobacillus curvatus is a species of gram-positive lactic acid bacteria in the family Lactobacillaceae. It is a facultatively heterofermentative bacterium commonly found in fermented foods, particularly fermented meat products. L. curvatus contributes to acidification, flavor development, and bacteriocin production during fermentation. Some strains also exhibit potential probiotic properties.
Taxonomy Latilactobacillus curvatus was originally described as Bacterium curvatum by Troili-Petersson in 1903. It was later renamed Lactobacillus curvatus and reclassified into the genus Latilactobacillus in 2020 following a comprehensive phylogenomic revision of the genus Lactobacillus. It is closely related to Latilactobacillus sakei. Subspecies previously proposed (e.g., "melibiosus") were later reclassified to other taxa.
Morphology and physiology Latilactobacillus curvatus cells are curved rods that occur singly, in pairs, or in short chains. Colonies are convex and opaque on standard LAB media. Most strains are non-motile and catalase-negative. However, motility has been confirmed in strain NRIC 0822, isolated from kabura-zushi, which carries a horizontally acquired flagellar operon. Latilactobacillus curvatus is facultatively heterofermentative, capable of producing lactic acid as the main fermentation product, along with minor amounts of acetic acid or CO2 under certain conditions. It is psychrotrophic and grows over a wide temperature range, including refrigeration temperatures. The genome size ranges from 1.8 to 2.0 Mb with a G+C content of 41–42%.
Ecology Latilactobacillus curvatus is primarily associated with fermented meat products like dry sausages and salami, as well as vacuum-packed and refrigerated meats. It is also found in fermented vegetables such as kimchi, sauerkraut, and pickles, as well as in dairy products, sourdough, and silage. It can occur transiently in the gastrointestinal tract of animals and humans, likely from dietary sources.
Role in food fermentation Latilactobacillus curvatus is used as a starter culture in meat fermentation for acidification and preservation. It is known for producing class IIa bacteriocins, such as curvacin A, which inhibit foodborne pathogens like Listeria monocytogenes. Due to this antimicrobial activity, some strains are used as protective cultures in ready-to-eat meat products.
Probiotic potential Several strains of L. curvatus have been evaluated for probiotic applications. A strain isolated from kimchi, WiKim38, was shown to induce IL-10 production and alleviate colitis symptoms in a mouse model, suggesting anti-inflammatory properties. Other strains demonstrate acid and bile tolerance, adhesion to intestinal cells, and inhibition of pathogens.
Genomics Comparative genomics has revealed two major lineages of L. curvatus distinguished by differences in carbohydrate metabolism and ecological specialization. Strains from plant-based environments often carry genes for degrading plant polysaccharides, while meat-associated strains may lack them. Many strains possess plasmid-encoded bacteriocins and stress response systems. Some have been reported to synthesize vitamins such as riboflavin and cobalamin.
References
