Symbiotic fermentation is a form of

fermentation Fermentation is a metabolic process that produces chemical changes in organic substrates through the action of enzymes. In biochemistry, it is narrowly defined as the extraction of energy from carbohydrates in the absence of oxygen. In food ...

in which multiple organisms (

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

acetic acid bacteria 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 ...

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 bacte ...

and others) interact in

symbiosis Symbiosis (from Greek , , "living together", from , , "together", and , bíōsis, "living") is any type of a close and long-term biological interaction between two different biological organisms, be it mutualistic, commensalistic, or parasit ...

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 chemistry, saccharification is a term for denoting any chemical change wherein a monosaccharide molecule remains intact after becoming unbound from another saccharide. For example, when a carbohydrate is broken into its component sugar molecul ...

in a mixed fermentation process.

History

The earliest mention of the term can be found in a lecture given by Dr.

Allan Macfadyen Allan Macfadyen (26 May 1860 in Glasgow – 1 March 1907 in Hampstead, London) was a Scottish bacteriologist, a pioneer in immunization against bacterial infection. Early life and education The youngest of four sons of a brass founder in G ...

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 ( ; also spelled as kephir or kefier; ; ; ) 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 pa ...

and

kumis ''Kumis'' (also spelled ''kumiss'' or ''koumiss'' or ''kumys'', see other transliterations and cognate words below under terminology and etymology – otk, airag kk, қымыз, ''qymyz'') mn, айраг, ''ääryg'') is a fermented dairy p ...

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

Aspergillus oryzae ''Aspergillus oryzae'', also known as , is a filamentous fungus (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 m ...

).'' In 1927, Dr.

Aldo Castellani Aldo Castellani, KCMG (8 September 1874 – 3 October 1971) was an Italian pathologist and bacteriologist A bacteriologist is a microbiologist, or similarly trained professional, in bacteriology -- a subdivision of microbiology that studies b ...

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 two- ...

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'' infecti ...

'') 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 lower ...

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

sake Sake, also spelled saké ( ; 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 indee ...

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

kombucha Kombucha (also tea mushroom, tea fungus, or Manchurian mushroom when referring to the culture; Latin name ''Medusomyces gisevii'') is a fermented, lightly effervescent, sweetened black tea drink commonly consumed for its purported health ben ...

has become a popular fermented beverage 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 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 s ...

formation, while the yeast produce

invertase Invertase is an enzyme that catalyzes the hydrolysis (breakdown) of sucrose (table sugar) into fructose and glucose. Alternative names for invertase include , saccharase, glucosucrase, beta-h-fructosidase, beta-fructosidase, invertin, sucrase, ma ...

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

Examples of symbiotic fermentation

Representation of Symbiotic Fermentation in Koji Culture

Kefir Kefir ( ; also spelled as kephir or kefier; ; ; ) 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 pa ...

**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, access-date=2020-11-07, editor2-last=Holban, editor2-first=Alina Maria *

Sake Sake, also spelled saké ( ; 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 indee ...

** In the making of Sake, Koji molds are used to ferment rice producing free sugars that are then fermented by lactic acid bacteria and yeast, providing ethanol and flavor active compounds. *

Lambic Beer Lambic () is a type of beer brewed in the Pajottenland region of Belgium southwest of Brussels and in Brussels itself since the 13th century. Types of lambic beers include gueuze, kriek lambic and framboise. Lambic differs from most other bee ...

** 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 acetic acid and trace compounds that may include flavorings. Vinegar typically contains 5–8% acetic acid by volume. Usually, the acetic acid is produced by a double fermentation, converting simple sugars to et ...

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

Soy Sauce Soy sauce (also called simply soy in American English and soya sauce in British English) is a liquid condiment of Chinese origin, traditionally made from a fermented paste of soybeans, roasted grain, brine, and '' Aspergillus oryzae'' or ''Asp ...

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

Whiskey Whisky or whiskey is a type of distilled alcoholic beverage made from fermented grain mash. Various grains (which may be malted) are used for different varieties, including barley, corn, rye, and wheat. Whisky is typically aged in wooden cask ...

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

Wine Wine is an alcoholic drink typically made from fermented grapes. Yeast consumes the sugar in the grapes and converts it to ethanol and carbon dioxide, releasing heat in the process. Different varieties of grapes and strains of yeasts are m ...

** Grapes are fermented by yeast and LAB. *

Kombucha Kombucha (also tea mushroom, tea fungus, or Manchurian mushroom when referring to the culture; Latin name ''Medusomyces gisevii'') is a fermented, lightly effervescent, sweetened black tea drink commonly consumed for its purported health ben ...

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

References

Fermentation Symbiosis