<i>Lactobacillus</i>

Abstract Lac.to.ba.cil'lus. L. neut. n. lac (gen. lactis ), milk; L. masc. n. bacillus , a small rod; N.L. masc. n. Lactobacillus , milk rodlet. Bacillota / “Bacilli” / Lactobacillales / Lactobacillaceae / Lactobacillus After reclassification of the lactobacilli, the genus Lactobacillus comprises 52 species of Gram‐stain‐positive, rod‐shaped, thermophilic, homofermentative bacteria with validly published names. Two of these species have been shown to be later synonyms, three others are today considered subspecies, and thus there are 47 species‐level taxa. Most strains grow up to 40–45°C, some up to 55°C. In comparison to other lactobacilli genera, strains of Lactobacillus are therefore referred to as thermophilic. Lactobacillus is adapted to a host associated lifestyle. Congruently, strains have small to medium sized genomes ranging from 1.27 to 2.33 Mb. The L. melliventris clade is found in bees in the family Apidae ; most of them are isolated from Apis mellifera, the honey bee. Most other species inhabit the intestine, oral cavity and reproductive tract of vertebrate hosts. The habitats of Lactobacillus species are often shared with heterofermentative lactobacilli. Lactobacillus species are of importance in many fermentation processes occurring during the production and preservation of food and feed, especially fermented dairy and plant products, but can also be associated with spoilage. The fermentation type is homolactic and many species ferment a variety of carbohydrates. Species that have adapted to specific narrow niches, such as the bee intestine, human vagina and dairy fermentations, utilize only a very reduced spectrum of carbohydrates. DNA G + C content (mol%) : 32.5–52.1 (genome). Type species : Lactobacillus delbrueckii Beijerinck 1901 AL (basonym: “Bacillus delbruecki” Leichmann 1896).