Vinegar is an aqueous solution of acetic acid and trace compounds that may include flavorings. Vinegar typically contains from 5% to 8% acetic acid by volume. Usually, the acetic acid is produced by a double fermentation, converting simple sugars to ethanol using yeast, and ethanol to acetic acid using acetic acid bacteria. Many types of vinegar are made, depending on source materials. The product is now mainly used in the culinary arts as a flavorful, acidic cooking ingredient, or in pickling. Various types are used as condiments or garnishes, including balsamic vinegar and malt vinegar.
Acetic acid bacteria (AAB) are a group of Gram-negative bacteria which oxidize sugars or ethanol and produce acetic acid during fermentation. The acetic acid bacteria consist of 10 genera in the family Acetobacteraceae. Several species of acetic acid bacteria are used in industry for production of certain foods and chemicals.
Mother of vinegar is a biofilm composed of a form of cellulose, yeast and bacteria that sometimes develops on fermenting alcoholic liquids during the process that turns alcohol into acetic acid with the help of oxygen from the air and AAB. It is similar to the SCOBY mostly known from production of kombucha, but develops to a much lesser extent due to lesser availability of yeast and a different population of bacteria. Mother of vinegar is often added to wine, cider, or other alcoholic liquids to produce vinegar at home, although only the bacteria is required, but historically has also been used in large scale production.
Sourdough or sourdough bread is a bread made by the fermentation of dough using wild lactobacillaceae and yeast. Lactic acid from fermentation imparts a sour taste and improves keeping qualities.
Lactobacillus is a genus of gram-positive, aerotolerant anaerobes or microaerophilic, rod-shaped, non-spore-forming bacteria. Until 2020, the genus Lactobacillus comprised over 260 phylogenetically, ecologically, and metabolically diverse species; a taxonomic revision of the genus assigned lactobacilli to 25 genera.
Kombucha is a fermented, lightly effervescent, sweetened black tea drink commonly consumed for its purported health benefits. Sometimes the beverage is called kombucha tea to distinguish it from the culture of bacteria and yeast. Juice, spices, fruit or other flavorings are often added.
Acetobacter is a genus of acetic acid bacteria. Acetic acid bacteria are characterized by the ability to convert ethanol to acetic acid in the presence of oxygen. Of these, the genus Acetobacter is distinguished by the ability to oxidize lactate and acetate into carbon dioxide and water. Bacteria of the genus Acetobacter have been isolated from industrial vinegar fermentation processes and are frequently used as fermentation starter cultures.
Malolactic conversion is a process in winemaking in which tart-tasting malic acid, naturally present in grape must, is converted to softer-tasting lactic acid. Malolactic fermentation is most often performed as a secondary fermentation shortly after the end of the primary fermentation, but can sometimes run concurrently with it. The process is standard for most red wine production and common for some white grape varieties such as Chardonnay, where it can impart a "buttery" flavor from diacetyl, a byproduct of the reaction.
Lactiplantibacillus plantarum is a widespread member of the genus Lactiplantibacillus and commonly found in many fermented food products as well as anaerobic plant matter. L. plantarum was first isolated from saliva. Based on its ability to temporarily persist in plants, the insect intestine and in the intestinal tract of vertebrate animals, it was designated as a nomadic organism. L. plantarum is Gram positive, bacilli shaped bacterium. L. plantarum cells are rods with rounded ends, straight, generally 0.9–1.2 μm wide and 3–8 μm long, occurring singly, in pairs or in short chains. L. plantarum has one of the largest genomes known among the lactic acid bacteria and is a very flexible and versatile species. It is estimated to grow between pH 3.4 and 8.8. Lactiplantibacillus plantarum can grow in the temperature range 12 °C to 40 °C. The viable counts of the "L. plantarum" stored at refrigerated condition (4 °C) remained high, while a considerable reduction in the counts was observed stored at room temperature.
Fructilactobacillus sanfranciscensis is a heterofermentative species of lactic acid bacteria which, through the production mainly of lactic and acetic acids, helps give sourdough bread its characteristic taste. It is named after San Francisco, where sourdough was found to contain the variety, though it is dominant in Type I sourdoughs globally. In fact, F. sanfranciscensis has been used in sourdough breads for thousands of years, and is used in 3 million tons of sourdough goods yearly.
Food microbiology is the study of the microorganisms that inhabit, create, or contaminate food. This includes the study of microorganisms causing food spoilage; pathogens that may cause disease ; microbes used to produce fermented foods such as cheese, yogurt, bread, beer, and wine; and microbes with other useful roles, such as producing probiotics.
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/, http://www.lactobacillus.uantwerpen.be/). 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.
Biotransformation is the biochemical modification of one chemical compound or a mixture of chemical compounds. Biotransformations can be conducted with whole cells, their lysates, or purified enzymes. Increasingly, biotransformations are effected with purified enzymes. Major industries and life-saving technologies depend on biotransformations.
Symbiotic culture of bacteria and yeast (SCOBY) is a culinary symbiotic fermentation culture (starter) consisting of lactic acid bacteria (LAB), acetic acid bacteria (AAB), and yeast which arises in the preparation of sour foods and beverages such as kombucha. Beer and wine also undergo fermentation with yeast, but the lactic acid bacteria and acetic acid bacteria components unique to SCOBY are usually viewed as a source of spoilage rather than a desired addition. Both LAB and AAB enter on the surface of barley and malt in beer fermentation and grapes in wine fermentation; LAB lowers the pH of the beer/wine while AAB takes the ethanol produced from the yeast and oxidizes it further into vinegar, resulting in a sour taste and smell. AAB are also responsible for the formation of the cellulose SCOBY.
Lentilactobacillus buchneri is a gram-positive, non-spore forming, anaerobic, rod prokaryote. L. buchneri is a heterofermentative bacteria that produces lactic acid and acetic acid during fermentation. It is used as a bacterial inoculant to improve the aerobic stability of silage. These bacteria are inoculated and used for preventing heating and spoilage after exposure to air.
Acetic acid, systematically named ethanoic acid, is an acidic, colourless liquid and organic compound with the chemical formula CH3COOH. Vinegar is at least 4% acetic acid by volume, making acetic acid the main component of vinegar apart from water and other trace elements.
Kefir is a fermented milk drink similar to a thin yogurt or ayran that is made from kefir grains, a specific type of mesophilic symbiotic culture. The drink originated in the North Caucasus, in particular the Elbrus region along the upper mountainous sections of Circassia, Karachay and Balkaria, from where it came to Russia, and from there it spread to Europe, Canada, and the United States, where it is prepared by inoculating the milk of cows, goats, or sheep with kefir grains.
Latilactobacillus sakei is the type species of the genus Latilactobacillus that was previously classified in the genus Lactobacillus. It is homofermentative; hexoses are metabolized via glycolysis to lactic acid as main metabolite; pentoses are fermented via the Phosphoketolase pathway to lactic and acetic acids.
Lactobacillus kefiranofaciens is a species of slime-forming, homofermentative, rod-shaped lactic acid bacteria first isolated from kefir grains, hence its name. Its type strain is WT-2B. Its genome has been sequenced. Lactobaccillus kefiranofaciens was first identified in 1967 in Russia through studying kefir granules. Lactobaccillus kefiranofaciens is part of the lactobacillus genus and firmicutes phylum of bacteria. These bacterium metabolize carbohydrates and produce lactic acid, which can be useful in fermentation. Two subspecies have been identified as kefirgranum and kefiranofaciens, which share properties such as being gram-positive, facultatively anaerobic, and rod-shaped.L. kefiranofaciens is the subspecies related to kefir granules. Studies have investigated the origins and causes for variation in kefir composition and led to conflicting results. Some studies indicate the presence of L.kefiranofaciens was due to geographical location, while others indicate it was due to the different milks used.
Secundilactobacillus collinoides is a rod shaped species of lactic acid bacteria found in fermenting apple juice or cider. It is part of the Lactobacillaceae family. It is Gram-positive, non-spore forming and non-motile prokaryote.
