Symbiotic fermentation is a form of

fermentation Fermentation is a type of anaerobic metabolism which harnesses the redox potential of the reactants to make adenosine triphosphate (ATP) and organic end products. Organic molecules, such as glucose or other sugars, are catabolized and reduce ...

in which multiple organisms (

yeast Yeasts are eukaryotic, single-celled microorganisms classified as members of the fungus kingdom (biology), kingdom. The first yeast originated hundreds of millions of years ago, and at least 1,500 species are currently recognized. They are est ...

acetic acid bacteria Acetic acid bacteria (AAB) are a group of Gram-negative bacteria which Oxidation, oxidize sugars or ethanol and produce acetic acid during Aerobic fermentation, fermentation. The acetic acid bacteria consist of 10 genus, genera in the family Acet ...

lactic acid bacteria Lactobacillales are an order of gram-positive, low-GC, acid-tolerant, generally nonsporulating, nonrespiring, either rod-shaped (bacilli) or spherical ( cocci) bacteria that share common metabolic and physiological characteristics. These bact ...

and others) interact in

symbiosis Symbiosis (Ancient Greek : living with, companionship < : together; and ''bíōsis'': living) is any type of a close and long-term biological interaction, between two organisms of different species. The two organisms, termed symbionts, can fo ...

in order to produce the desired product. For example, a yeast may produce ethanol, which is then consumed by an acetic acid bacterium. Described early on as the fermentation of sugars following saccharification in a mixed fermentation process.

History

The earliest mention of the term can be found in a lecture given by Dr. Allan Macfadyen of the Jenner Institute of Preventative Medicine in 1902. Dr. Macfadyen described symbiotic fermentation as noting "a close relationship between the organisms at work, the action of one aiding or modifying the action of the other, whilst both members are more active as a results of the partnership." Fermentative microorganisms have had a deep history as seen by

kefir Kefir ( ; alternative spellings: kephir or kefier; ; ; ) is a Fermented milk products, fermented milk drink similar to a thin yogurt or ayran that is made from kefir grains, a specific type of mesophilic SCOBY, symbiotic culture. It is prep ...

and

kumis ''Kumis'' ( , ), alternatively spelled ''coumis'' or ''kumyz'', also known as ''airag'' ( ), is a traditional Fermented milk products, fermented dairy product made from mare milk. The drink is important to the peoples of the Central and East ...

fermentations of milk by Nomadic tribes in Russia, as well as Japanese koji fermentation (see ''

Aspergillus oryzae ''Aspergillus oryzae'', also known as , is a mold used in East Asia to saccharify rice, sweet potato, and barley in the making of alcoholic beverages such as '' sake'' and '' shōchū'', and also to ferment soybeans for making soy sauce and '' ...

).'' In 1927, Dr. Aldo Castellani defined symbiotic fermentation as "two microorganisms neither of which alone produces fermentation with gas in certain carbohydrates, may do so when living in symbiosis or when artificially mixed." He based this definition on the observation that ordinary bakers yeast consisted of two or more microorganisms- ''Saccharomyces'' and ''Bacilli.'' He performed experiments to show that when two different ''Bacilli'' species were grown in culture together with

maltose } Maltose ( or ), also known as maltobiose or malt sugar, is a disaccharide formed from two units of glucose joined with an α(1→4) bond. In the isomer isomaltose, the two glucose molecules are joined with an α(1→6) bond. Maltose is the tw ...

as the sugar, gas was produced as a result of symbiotic fermentation. Dr. Castellani also described symbiotic fermentation as a method to distinguish between ''Bacillus dysentariae'' Shiga (now '' Shigella dysentariae'' Shiga) and ''B. dysentariae'' Flexner (now ''

Shigella flexneri ''Shigella flexneri'' is a species of Gram-negative bacteria in the genus ''Shigella'' that can cause diarrhea in humans. Several different serogroups of ''Shigella'' are described; ''S. flexneri'' belongs to group ''B''. ''S. flexneri'' infect ...

'') by fermenting each of them with ''Bacillus morgani'' (now '' Morganella morganii'') in

mannitol Mannitol is a type of sugar alcohol used as a sweetener and medication. It is used as a low calorie sweetener as it is poorly absorbed by the intestines. As a medication, it is used to decrease pressure in the eyes, as in glaucoma, and to l ...

. The culture with Flexner would always produce gas and acid, while the culture with Shiga only produced acid. To summarize, one bacteria performs acid fermentation to produce acid from sugar, then the other bacteria performs gas fermentation using the acid products to produce gas. Thus creating a type of symbiotic relationship based on fermentation metabolism. More recently, symbiotic fermentation is described in a traditional sense for the fermentation of food and beverage products.

Biofilm A biofilm is a Syntrophy, syntrophic Microbial consortium, community of microorganisms in which cell (biology), cells cell adhesion, stick to each other and often also to a surface. These adherent cells become embedded within a slimy ext ...

aggregates of fermentative microorganisms are commonly associated with fermentation of many products including vinegar,

sake Sake, , or saki, also referred to as Japanese rice wine, is an alcoholic beverage of Japanese origin made by fermenting rice that has been polished to remove the bran. Despite the name ''Japanese rice wine'', sake, and indeed any East Asi ...

, shochu, and kefir. In the U.S.,

kombucha Kombucha (also tea mushroom, tea fungus, or Manchurian mushroom when referring to the Microbiological culture, culture; Latin name ''Medusomyces gisevii'') is a fermented beverage, fermented, effervescent, Sweetened beverage, sweetened black ...

has become a popular

fermented beverage This is a list of fermented foods, which are foods produced or preserved by the action of microorganisms. In this context, Fermentation in food processing, fermentation typically refers to the fermentation of sugar to ethanol, alcohol using yeas ...

that is also a model of symbiotic fermentation. In kombucha, bacteria create the biofilm network that initiates

SCOBY Symbiotic culture of bacteria and yeast (SCOBY) is a culinary symbiosis, symbiotic fermentation Microbial food cultures, culture (Fermentation starter, starter) consisting of lactic acid bacteria (LAB), acetic acid bacteria (AAB), and yeast whic ...

formation, while the yeast produce

invertase β-Fructofuranosidase is an enzyme that catalyzes the hydrolysis (breakdown) of the table sugar sucrose into fructose and glucose. Sucrose is a fructoside. Alternative names for β-fructofuranosidase include invertase, saccharase, glucosucrase ...

that makes sugars available to the bacteria and yeast for fermentation.

Examples of symbiotic fermentation

Representation of Symbiotic Fermentation in Koji Culture

Kefir Kefir ( ; alternative spellings: kephir or kefier; ; ; ) is a Fermented milk products, fermented milk drink similar to a thin yogurt or ayran that is made from kefir grains, a specific type of mesophilic SCOBY, symbiotic culture. It is prep ...

**In Kefir, the lactose in milk is fermented by lactic acid bacteria to produce lactic acid, further breakdown to propionic acid is done by propionibacteria. Yeast in Kefir ferment to produce ethanol, which is consumed by other bacteria to make acids and aldehydes that contribute to flavor.{{Citation, last=Van Wyk, first=Jessy, title=12 - Kefir: The Champagne of Fermented Beverages, date=2019-01-01, url=http://www.sciencedirect.com/science/article/pii/B9780128152713000129, work=Fermented Beverages, pages=473–527, editor-last=Grumezescu, editor-first=Alexandru Mihai, publisher=Woodhead Publishing, language=en, doi=10.1016/b978-0-12-815271-3.00012-9, isbn=978-0-12-815271-3, s2cid=108073995 , access-date=2020-11-07, editor2-last=Holban, editor2-first=Alina Maria, url-access=subscription *

Sake Sake, , or saki, also referred to as Japanese rice wine, is an alcoholic beverage of Japanese origin made by fermenting rice that has been polished to remove the bran. Despite the name ''Japanese rice wine'', sake, and indeed any East Asi ...

** In the making of Sake, Koji molds are used to ferment rice producing free sugars that are then fermented by lactic acid bacteria (LAB) and yeast, providing ethanol and flavor active compounds. * Lambic Beer ** Wheat is fermented by yeast and LAB. * Shochu ** Rice, wheat, and batata are fermented by mold, yeast, and LAB. *

Vinegar Vinegar () is an aqueous solution of diluted acetic acid and trace compounds that may include flavorings. Vinegar typically contains from 5% to 18% acetic acid by volume. Usually, the acetic acid is produced by a double fermentation, converting ...

** Rice is fermented by mold, yeast, LAB, and acetic acid bacteria. *

Soy Sauce Soy sauce (sometimes called soya sauce in British English) is a liquid condiment of China, Chinese origin, traditionally made from a fermentation (food), fermented paste of soybeans, roasted cereal, grain, brine, and ''Aspergillus oryzae'' or ''A ...

** Soy bean and wheat are fermented by mold, yeast, and LAB. *

Whiskey Whisky or whiskey is a type of liquor made from Fermentation in food processing, fermented grain mashing, mash. Various grains (which may be Malting, malted) are used for different varieties, including barley, Maize, corn, rye, and wheat. Whisky ...

** Barley, corn, and rye are fermented by yeast and LAB. *

Wine Wine is an alcoholic drink made from Fermentation in winemaking, fermented fruit. Yeast in winemaking, Yeast consumes the sugar in the fruit and converts it to ethanol and carbon dioxide, releasing heat in the process. Wine is most often made f ...

** Grapes are fermented by yeast and LAB. *

Kombucha Kombucha (also tea mushroom, tea fungus, or Manchurian mushroom when referring to the Microbiological culture, culture; Latin name ''Medusomyces gisevii'') is a fermented beverage, fermented, effervescent, Sweetened beverage, sweetened black ...

** Tea and sucrose are fermented by yeast and acetic acid bacteria from a

References

Fermentation Symbiosis