Zygosaccharomyces rouxii | |
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Zygosaccharomyces rouxii growing on media with different carbon sources | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Fungi |
Division: | Ascomycota |
Class: | Saccharomycetes |
Order: | Saccharomycetales |
Family: | Saccharomycetaceae |
Genus: | Zygosaccharomyces |
Species: | Z. rouxii |
Binomial name | |
Zygosaccharomyces rouxii | |
Zygosaccharomyces rouxii is a species of yeast in the genus Zygosaccharomyces. Initially described as Saccharomyces rouxii by Boutroux in 1883, it was then moved to the genus Zygosaccharomyces in the work of Barnett et al. [1] It is remarkably tolerant of high concentrations of sugar or salt, making it a spoilage agent of otherwise stable foods, but also present in fermentation of products such as soy sauce or balsamic vinegar.
It is a diploid, homothallic, and osmophilic (capable of withstanding high osmotic pressures, such as high concentrations of sugar) yeast. It produces ethanol by alcoholic fermentation.
It is found on grapes, in urine, fermented foods, syrups (maple), honey, grape juice concentrate, marzipan, candied fruit, [2] miso, marmalade, and wine. [1]
It is capable of fermenting dextrose (D-glucose) and maltose but has no fermentation activity on sucrose and lactose. Cells are small, round or oval and linked together in chains. [3] It is particularly tolerant of a wide range of acidity and sugar and salt concentration but is sensitive to temperatures above 35°C unless protected by a small amount of sugar in the medium. [4]
In lab, is grown on malt extract agar. After 3 days at 25°C, cells are spheroidal to cylindrical, either singly or in pairs or sometimes in small clumps. [5]
Two collaborators of Louis Pasteur are the origin of the discovery of this new yeast: it was isolated by Émile Roux from fermenting fruit juice and was described as Saccharomyces rouxi by Léon Boutroux in 1883.
It has been described multiple times under different names. See the Catalogue of Life checklist.
It has been genetically sequenced in 2009. [6]
In food, this yeast is used in the fermentation of soybeans during the manufacture of soy sauce and miso where it plays an important role in the development of aromas. It is also present in the fermentation of traditional Italian balsamic vinegar. [N 1] [7]
In the manufacture of soy sauce, soybeans and grain are inoculated with mold cultures such as Aspergillus oryzae to make what is called koji, then it is put in brine and seeded with the lactic acid bacteria Tetragenococcus halophilus (=Pediococcus halophilus) which produces lactic acid then with Zygosaccharomyces rouxii which ferments alcohol. [8]
Miso is obtained from a cereal koji seeded with a mold (Aspergillus oryzae) which is then salted and fermented by lactic acid bacteria. (Enterococcus, Pediococcus...) and yeasts like Z. rouxii.
Z. rouxii produces alcoholic fermentation and hydrolyzes various amino acids into their respective alcohols. [9] It synthesises aromatic components HEMF and HDMF. [N 2]
Z. rouxii can cause spoilage of certain high-sugar and high-salt foods such as condensed milk, fruit juices, jam, pastries and salad dressings. [10] It causes alcoholic fermentation: the alteration of the product is manifested by an alcoholic taste and especially by an intense gas release which makes the drink fizzy and which can cause the packaging to swell. [8]
Miso is a traditional Japanese seasoning. It is a thick paste produced by fermenting soybeans with salt and kōji and sometimes rice, barley, seaweed, or other ingredients. It is used for sauces and spreads, pickling vegetables, fish, or meats, and mixing with dashi soup stock to serve as miso soup, a Japanese culinary staple. Miso is high in protein and rich in vitamins and minerals, and it played an important nutritional role in feudal Japan. Miso is still widely used in both traditional and modern cooking in Japan and has been gaining worldwide interest.
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 acetic acid bacteria (AAB). It is similar to the symbiotic culture of bacteria and yeast (SCOBY) mostly known from production of kombucha, but develops to a much lesser extent due to lesser availability of yeast, which is often no longer present in wine/cider at this stage, 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.
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.
Fermented tofu is a Chinese condiment consisting of a form of processed, preserved tofu used in East Asian cuisine. The ingredients typically are soybeans, salt, rice wine and sesame oil or vinegar. In mainland China the product is often freshly distributed. In overseas Chinese communities living in Southeast Asia, commercially packaged versions are often sold in jars containing blocks 2- to 4-cm square by 1 to 2 cm thick soaked in brine with select flavorings.
Zygosaccharomyces bailii is a species in the genus Zygosaccharomyces. It was initially described as Saccharomyces bailii by Lindner in 1895, but in 1983 it was reclassified as Zygosaccharomyces bailii in the work by Barnett et al.
In food processing, fermentation is the conversion of carbohydrates to alcohol or organic acids using microorganisms—yeasts or bacteria—under anaerobic (oxygen-free) conditions. Fermentation usually implies that the action of microorganisms is desired. The science of fermentation is known as zymology or zymurgy.
Candida stellata is a species of yeast of the genus Candida. The year of 1978 saw work of Yarrow & Meyer the yeast was reclassified to its current name from Saccharomyces stellatus, which was initially described by Kroemer and Krumbholz in 1931.
Fermented bean paste is a category of fermented foods typically made from ground soybeans, which are indigenous to the cuisines of East, South and Southeast Asia. In some cases, such as the production of miso, other varieties of beans, such as broad beans, may also be used.
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.
The process of fermentation in winemaking turns grape juice into an alcoholic beverage. During fermentation, yeasts transform sugars present in the juice into ethanol and carbon dioxide. In winemaking, the temperature and speed of fermentation are important considerations as well as the levels of oxygen present in the must at the start of the fermentation. The risk of stuck fermentation and the development of several wine faults can also occur during this stage, which can last anywhere from 5 to 14 days for primary fermentation and potentially another 5 to 10 days for a secondary fermentation. Fermentation may be done in stainless steel tanks, which is common with many white wines like Riesling, in an open wooden vat, inside a wine barrel and inside the wine bottle itself as in the production of many sparkling wines.
Tetragenococcus halophilus is a halophilic lactic acid bacterium active in the fermentation processes of soy sauce, miso, fish sauce and salted anchovies.
Yeast assimilable nitrogen or YAN is the combination of free amino nitrogen (FAN), ammonia (NH3) and ammonium (NH4+) that is available for a yeast, e.g. the wine yeast Saccharomyces cerevisiae, to use during fermentation. Outside of the fermentable sugars glucose and fructose, nitrogen is the most important nutrient needed to carry out a successful fermentation that doesn't end prior to the intended point of dryness or sees the development of off-odors and related wine faults. To this extent winemakers will often supplement the available YAN resources with nitrogen additives such as diammonium phosphate (DAP).
Symbiotic fermentation is a form of fermentation in which multiple organisms interact in symbiosis 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.
Nuruk (누룩) is a traditional Korean fermentation starter. It is used to make various types of Korean alcoholic beverages including takju, cheongju, and soju. It is an essential ingredient in Shindari and is mixed with rice. Historically, it was used in a variety of provinces of Korea, including Jeju Island.
Hanseniaspora opuntiae is a species of yeast in the family Saccharomycetaceae. It has been isolated from locations worldwide, on grape berries and on prickly pear cacti.
Hanseniaspora osmophila is a species of yeast in the family Saccharomycetaceae. It is found in soil and among the bark, leaves, and fruits of plants, as well as fermented foods and beverages made from fruit.
Saccharomycodes ludwigii is a yeast species best known for being a contaminant in alcohol and fruit juice production. It is highly resistant to typical environmental stressors such as high temperature, high sugar concentration, and high sulfur dioxide concentration. It is often referred to as the "winemaker's nightmare," as it contaminates products by outcompeting desirable yeast species. However, S. ludwigii strains are currently being tested in the growing low-alcohol beer industry.