Levilactobacillus brevis

Levilactobacillus brevis is a gram-positive, rod shaped species of lactic acid bacteria which is heterofermentative, creating CO2, lactic acid and acetic acid or ethanol during fermentation. L. brevis is the type species of the genus Levilactobacillus (previously L. brevis group), which comprises 24 species (http://www.lactobacillus.ualberta.ca/, ). It can be found in many different environments, such as fermented foods, and as normal microbiota. L.brevis is found in food such as sauerkraut and pickles. It is also one of the most common causes of beer spoilage. Ingestion has been shown to improve human immune function, and it has been patented several times. Normal gut microbiota L.brevis is found in human intestines, vagina, and feces. L. brevis is one of the major lactobacilli found in tibicos grains, used to make kefir, but Lentilactobacillus species are responsible for the production of the polysaccharide (dextran and kefiran) that forms the grains. Major metabolites of L. brevis include lactic acid and ethanol. Strains of L. brevis and L. hilgardii have been found to produce the biogenic amines tyramine and phenylethylamine. E.B.Fred, W.H. Peterson, and J.A. Anderson initially discovered the species in 1921 and the it was categorized based on the ability to metabolize certain carbon and sugars. This early study showed that this can produce acetic acid, carbon dioxide and large amounts of mannitol. Mannitol which is another carbon source that can be used to produce lactic acid. L. brevis has been shown to actively transport glucose and galactose. When fructose was used as a carbon source there was only some growth and L. brevis was able to partially metabolize the fructose to mannitol. There are some strains that poorly metabolize glucose but prefer disaccharides as carbon source. By using the fermentation pathway the end result is lactic acid and acetic acid. It appears that under high temperature conditions, 50 degrees Celsius and in acidic environments the survival of this bacteria is longer than most bacteria under acidic conditions, the bacteria can live about 45 minutes.