The Lactobacillales are an order of Gram-positive

Gram-positive

Gram-positive bacteria are those that are stained dark blue or violet by Gram staining. This is in contrast to Gram-negative bacteria, which cannot retain the crystal violet stain, instead taking up the counterstain and appearing red or pink...

 bacteria

Bacteria

Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...

 that comprise the lactic acid bacteria

Lactic acid bacteria

The lactic acid bacteria comprise a clade of Gram-positive, low-GC, acid-tolerant, generally non-sporulating, non-respiring rod or cocci that are associated by their common metabolic and physiological characteristics. These bacteria, usually found in decomposing plants and lactic products, produce...

. They are widespread in nature, and are found in soil, water, plants and animals. They are widely used in the production of fermented foods

Fermentation (food)

Fermentation in food processing typically is the conversion of carbohydrates to alcohols and carbon dioxide or organic acids using yeasts, bacteria, or a combination thereof, under anaerobic conditions. Fermentation in simple terms is the chemical conversion of sugars into ethanol...

, including dairy products such as yogurt, cheese

Cheese

Cheese is a generic term for a diverse group of milk-based food products. Cheese is produced throughout the world in wide-ranging flavors, textures, and forms....

, butter

Butter

Butter is a dairy product made by churning fresh or fermented cream or milk. It is generally used as a spread and a condiment, as well as in cooking applications, such as baking, sauce making, and pan frying...

, buttermilk

Buttermilk

Buttermilk refers to a number of dairy drinks. Originally, buttermilk was the liquid left behind after churning butter out of cream. It also refers to a range of fermented milk drinks, common in warm climates where unrefrigerated fresh milk otherwise sours quickly...

, kefir

Kefir

Kefir is a fermented milk drink that originated with shepherds of the North Caucasus region, who discovered that fresh milk carried in leather pouches would occasionally ferment into an effervescent beverage...

 and koumiss. LAB are also responsible for the malolactic fermentation

Malolactic fermentation

Malolactic fermentation is a process in winemaking where tart-tasting malic acid, naturally present in grape must, is converted to softer-tasting lactic acid. Malolactic fermentation tends to create a rounder, fuller mouthfeel. It has been said that malic acid tastes of green apples...

 process in wine

Wine

Wine is an alcoholic beverage, made of fermented fruit juice, usually from grapes. The natural chemical balance of grapes lets them ferment without the addition of sugars, acids, enzymes, or other nutrients. Grape wine is produced by fermenting crushed grapes using various types of yeast. Yeast...

 production, and the fermenting of salted cabbage to sauerkraut

Sauerkraut

Sauerkraut , directly translated from German: "sour cabbage", is finely shredded cabbage that has been fermented by various lactic acid bacteria, including Leuconostoc, Lactobacillus, and Pediococcus. It has a long shelf-life and a distinctive sour flavor, both of which result from the lactic acid...

.

Lactic acid bacteria genera

• Abiotrophia
  Abiotrophia
  Abiotrophia is a genus of lactic acid bacteria, a family in the phylum Firmicutes .-Species:The genus contains 4 species of coccus shaped species, 2 are former members of the genus Streptococcus, which were transferred in 1995 to the newly coined genus Abiotrophia:* A. adiacens Abiotrophia is a...
  
  
• Aerococcus
  Aerococcus
  Aerococcus is a genus in the phylum Firmicutes .-Etymology:The name Aerococcus derives from:Greek masculine gender noun aer, aeros , air; New Latin masculine gender noun coccus , a berry; New Latin masculine gender noun Aerococcus, air coccus.-Species:The genus contains 7 species, namely* A...
  
  
• Carnobacterium
  Carnobacterium
  Carnobacterium is a genus of Gram-positive bacteria within the family Leuconostocaceae. C. divergens and C. maltaromaticum are found in the wild and in food products and can grow anaerobically. These species are not known to be pathogenic in humans but may cause disease in fish....
  
  
• Enterococcus
  Enterococcus
  Enterococcus is a genus of lactic acid bacteria of the phylum Firmicutes. Enterococci are Gram-positive cocci that often occur in pairs or short chains, and are difficult to distinguish from streptococci on physical characteristics alone. Two species are common commensal organisms in the...
  
  
• Lactobacillus
  Lactobacillus
  Lactobacillus is a genus of Gram-positive facultative anaerobic or microaerophilic rod-shaped bacteria. They are a major part of the lactic acid bacteria group, named as such because most of its members convert lactose and other sugars to lactic acid. They are common and usually benign...
  
  
• Lactococcus
  Lactococcus
  Lactococcus is a genus of lactic acid bacteria that were formerly included in the genus Streptococcus Group N1. They are known as homofermentors meaning that they produce a single product, lactic acid in this case, as the major or only product of glucose fermentation...
  
  
• Leuconostoc
  Leuconostoc
  Leuconostoc is a genus of Gram-positive bacteria, placed within the family of Leuconostocaceae. They are generally ovoid cocci often forming chains. Leuconostoc spp. are intrinsically resistant to vancomycin and are catalase-negative . All species within this genus are heterofermentative and are...
  
  
• Oenococcus
  Oenococcus
  Oenococcus is a genus of Gram-positive bacteria, placed within the family of Leuconostocaceae. The only species in the genus used to be Oenococcus oeni . In 2006, the species Oenococcus kitaharae was identified...
  
  
• Pediococcus
  Pediococcus
  Pediococcus is a genus of Gram-positive lactic acid bacteria, placed within the family of Lactobacillaceae. They usually occur in pairs or tetrads, and divide along two planes of symmetry, as do the other lactic acid cocci genera Aerococcus and Tetragenococcus. They are purely homofermentative...
  
  
• Streptococcus
  Streptococcus
  Streptococcus is a genus of spherical Gram-positive bacteria belonging to the phylum Firmicutes and the lactic acid bacteria group. Cellular division occurs along a single axis in these bacteria, and thus they grow in chains or pairs, hence the name — from Greek στρεπτος streptos, meaning...
  
  
• Tetragenococcus
• Vagococcus
• Weissella
  Weissella
  Weissella is a genus of Gram-positive bacteria, placed within the family of Leuconostocaceae. The morphology of weissellas varies from spherical or lenticular cells to irregular rods.-External links:**...