Leuconostoc species are epiphytic bacteria that are wide spread in the natural environment and play an important role in several industrial and food fermentations. Leuconostoc mesenteroides is a facultative anaerobe requiring complex growth factors and amino acids. It is asporogenous and non-motile. Most strains in liquid culture appear as cocci, however, cells grown in glucose or on solid media may have an elongated or rod shaped morphology. A variety of lactic acid bacteria (LAB), including Leuconostoc species are commonly found on crop plants.

L. mesenteroides is perhaps the most predominant LAB species found on fruits and vegetables and is responsible for initiating the sauerkraut and other vegetable fermentations. L. mesenteroides starter cultures also used in some dairy and bread dough. Under microaerophilic conditions, a heterolactic fermentation is carried out. Glucose and other hexose sugars are converted to equimolar amount of D-lactate, ethanol and CO2 via a combination of the hexose monophosphate and pentose phosphate. Other metabolic pathways include conversion of citrate to diacetyl and acetoin and the production of dextrans and levan from sucrose. Commercial production dextrans and levans by L. mesenteroides, for use in the biochemical and pharmaceutical industry, has been carried out for more than 50 years. Dextrans are used in the manufacture of blood plasma extenders, heparin substitutes for anticoagulant therapy, cosmetics, and other products. Another use of dextrans is the manufacture of Sephadex gels or beads, which are widely used for industrial and laboratory protein separations. Thus L. mesenteroides has significant roles in both industrial and food fermentations. Interestingly the first observation of the production of polysaccharide "slime" from sugar, dates to the earliest days of the science of microbiology; Pasteur (1861) attributed this activity to small cocci, presumably Leuconostoc species. Viscous polysaccharides produced by L. mesenteroides are widely recognized as causing product losses and processing problems in the production of sucrose from sugar cane and sugar beets (adapted from genome.jgi-psf.org/finished_microbes/leume/leume.home.html).