Leuconostoc citreum
Leuconostoc citreum is a species of Gram-positive, coccus-shaped bacteria in the family Lactobacillaceae. It was first described in 1989 in a study of vancomycin-resistant Leuconostoc spp. isolates.
Taxonomy
L. citreum belongs to the genus Leuconostoc within the order Lactobacillales, a group of lactic acid bacteria. It is closely related to Leuconostoc pseudomesenteroides and Leuconostoc mesenteroides but can be distinguished by nucleic acid homology and biochemical traits.
Cells of L. citreum are cocci that typically occur in pairs and chains. The species is facultatively anaerobic, catalase-negative, and heterofermentative, producing lactic acid, ethanol or acetate, and carbon dioxide from sugar fermentation. Like other Leuconostoc species, it is intrinsically resistant to vancomycin due to the structure of its cell wall peptidoglycan, which incorporates precursors terminating in lactate instead of alanine.
Ecology
L. citreum is naturally associated with plant material and fermented foods. It has been isolated from kimchi, sourdough, pickled vegetables, and other fermented food products. It plays a role in flavor, texture, and acid development in traditional fermentations.
Industrial significance
L. citreum has been developed as a starter culture in kimchi and other vegetable fermentations to improve product quality and safety. It has been investigated for exopolysaccharide production, which can improve the texture of fermented foods such as sourdough and dairy products. Some strains also produce bacteriocins with potential use as natural food preservatives.