WordNet

single-celled yeasts that reproduce asexually by budding; used to ferment carbohydrates (同)genus Saccharomyces

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2015/09/06 06:00:07」(JST)

wiki en

Saccharomyces is a genus in the kingdom of fungi that includes many species of yeast. Saccharomyces is from Greek σάκχαρ (sugar) and μύκης (mushroom) and means sugar fungus. Many members of this genus are considered very important in food production. It is known as the brewer's yeast or baker's yeast. They are unicellular and saprophytic fungi. One example is Saccharomyces cerevisiae, which is used in making wine, bread, and beer. Other members of this genus include the wild yeast Saccharomyces paradoxus that is the closest relative to S. cerevisiae, Saccharomyces bayanus, used in making wine, and Saccharomyces boulardii, used in medicine.

Morphology

Colonies of Saccharomyces grow rapidly and mature in three days. They are flat, smooth, moist, glistening or dull, and cream to tannish cream in color. The inability to use nitrate and ability to ferment various carbohydrates are typical characteristics of Saccharomyces.

Cellular morphology

Generally, they have a diameter of 2-8μm and length of 3-25μm. Blastoconidia (cell buds) are observed. They are unicellular, globose, and ellipsoid to elongate in shape. Multilateral (multipolar) budding is typical. Pseudohyphae, if present, are rudimentary. Hyphae are absent.

Saccharomyces produces ascospores, especially when grown on V-8 medium, acetate ascospor agar, or Gorodkowa medium. These ascospores are globose and located in asci. Each ascus contains 1-4 ascospores. Asci do not rupture at maturity. Ascospores are stained with Kinyoun stain and ascospore stain. When stained with Gram stain, ascospores appear Gram-negative, while vegetative cells appear Gram-positive.

History

The presence of yeast in beer was first suggested in 1680, although the genus was not named Saccharomyces until 1837. It was not until 1876 that Louis Pasteur demonstrated the involvement of living organisms in fermentation and in 1883, Emil C. Hansen isolated brewing yeast and propagated the culture, leading to the discovery of the importance of yeast in brewing.^[1] The use of microscopes for the study of yeast morphology and purity was crucial to understanding their functionality.

Use in brewing

Saccharomyces cerevisiae—the yeast most used for brewing and baking

Numbered ticks are 10 micrometres apart.

Brewing yeasts are polyploid and belong to the Saccharomyces genera. The brewing strains can be classified into two groups; the ale strains (Saccharomyces cerevisiae) and the lager strains (Saccharomyces pastorianus or Saccharomyces carlsbergensis in the old taxonomy). Lager strains are a hybrid strain of S. cerevisiae and S. eubayanus and are often referred to as bottom fermenting. In contrast, ale strains are referred to as top fermenting strains, reflecting their separation characteristics in open square fermenters. Although the two species differ in a number of ways, including their response to temperature, sugar transport and use, the S. pastorianus and S. cerevisiae species are closely related within the Saccharomyces genus.

Saccharomyces yeasts can form symbiotic matrices with bacteria, and are used to produce kombucha, kefir and ginger beer.

Pathology

Saccharomyces cause food spoilage of sugar-rich foods, such as maple sap, syrup, concentrated juices and condiments.^[2] Case report suggest extended exposure to S. cerevisiae can result in hypersensitivity.^[3]

References

^ Boulton, Chris and Quain, David. Brewing yeast and fermentation. John Wiley & Sons, 2001, p. 18
^ MICROBES INVOLVED IN FOOD SPOILAGE Authors: Gabriel Chavarria, Julia Neal, Parul Shah, Katrina Pierzchala, Bryant Conger
^ Yamamoto Y, Osanai S, Fujiuchi S et al. (2002). "[Saccharomyces-induced hypersensitivity pneumonitis in a dairy farmer: a case report]". Nihon Kokyuki Gakkai Zasshi (in Japanese) 40 (6): 484–8. PMID 12325333.

External links

Saccharomyces Genome Database
Saccharomyces at NCBI taxonomy browser

UpToDate Contents

全文を閲覧するには購読必要です。 To read the full text you will need to subscribe.

1. 成人におけるクローン病の臨床症状、診断、および予後 clinical manifestations diagnosis and prognosis of crohn disease in adults
2. 抗真菌剤感受性試験 antifungal susceptibility testing
3. クロストリジウム・ディフィシルとプロバイオティクス clostridium difficile and probiotics
4. 3歳以上の小児における体重増加不良 poor weight gain in children older than two years of age
5. 消化器疾患に対するプロバイオティクス probiotics for gastrointestinal diseases

English Journal

The effects of engineered nanoparticles on the cellular structure and growth of Saccharomyces cerevisiae.

Bayat N, Rajapakse K, Marinsek-Logar R, Drobne D, Cristobal S.Author information Department of Biochemistry and Biophysics, Stockholm University , Stockholm , Sweden.AbstractAbstract In order to study the effects of nanoparticles (NPs) with different physicochemical properties on cellular viability and structure, Saccharomyces cerevisiae were exposed to different concentrations of TiO2-NPs (1-3 nm), ZnO-NPs (<100 nm), CuO-NPs (<50 nm), their bulk forms, Ag-NPs (10 nm) and single-walled carbon nanotubes (SWCNTs). The GreenScreen assay was used to measure cyto- and genotoxicity, and transmission electron microscopy (TEM) used to assess ultrastructure. CuO-NPs were highly cytotoxic, reducing the cell density by 80% at 9 cm(2)/ml, and inducing lipid droplet formation. Cells exposed to Ag-NPs (19 cm(2)/ml) and TiO2-NPs (147 cm(2)/ml) contained dark deposits in intracellular vacuoles, the cell wall and vesicles, and reduced cell density (40 and 30%, respectively). ZnO-NPs (8 cm(2)/ml) caused an increase in the size of intracellular vacuoles, despite not being cytotoxic. SWCNTs did not cause cytotoxicity or significant alterations in ultrastructure, despite high oxidative potential. Two genotoxicity assays, GreenScreen and the comet assay, produced different results and the authors discuss the reasons for this discrepancy. Classical assays of toxicity may not be the most suitable for studying the effects of NPs in cellular systems, and the simultaneous assessment of other measures of the state of cells, such as TEM are highly recommended.
Nanotoxicology.Nanotoxicology.2014 Jun;8:363-73. doi: 10.3109/17435390.2013.788748. Epub 2013 Apr 22.
Abstract In order to study the effects of nanoparticles (NPs) with different physicochemical properties on cellular viability and structure, Saccharomyces cerevisiae were exposed to different concentrations of TiO2-NPs (1-3 nm), ZnO-NPs (<100 nm), CuO-NPs (<50 nm), their bulk forms, Ag-NPs (10
PMID 23521755

Succinic acid in levels produced by yeast (Saccharomyces cerevisiae) during fermentation strongly impacts wheat bread dough properties.

Jayaram VB1, Cuyvers S1, Verstrepen KJ2, Delcour JA1, Courtin CM3.Author information 1Laboratory of Food Chemistry and Biochemistry, Leuven Food Science and Nutrition Research Centre (LFoRCe) KU Leuven, Kasteelpark Arenberg 20 - Box 2463, B-3001 Leuven, Belgium.2VIB Laboratory for Systems Biology & CMPG Laboratory for Genetics and Genomics, KU Leuven, Bio-Incubator, Gaston Geenslaan 1, B-3001 Leuven, Belgium.3Laboratory of Food Chemistry and Biochemistry, Leuven Food Science and Nutrition Research Centre (LFoRCe) KU Leuven, Kasteelpark Arenberg 20 - Box 2463, B-3001 Leuven, Belgium. Electronic address: christophe.courtin@biw.kuleuven.be.AbstractSuccinic acid (SA) was recently shown to be the major pH determining metabolite produced by yeast during straight-dough fermentation (Jayaram et al., 2013), reaching levels as high as 1.6mmol/100g of flour. Here, the impact of such levels of SA (0.8, 1.6 and 2.4mmol/100g flour) on yeastless dough properties was investigated. SA decreased the development time and stability of dough significantly. Uniaxial extension tests showed a consistent decrease in dough extensibility upon increasing SA addition. Upon biaxial extension in the presence of 2.4mmol SA/100g flour, a dough extensibility decrease of 47-65% and a dough strength increase of 25-40% were seen. While the SA solvent retention capacity of flour increased with increasing SA concentration in the solvent, gluten agglomeration decreased with gluten yield reductions of over 50%. The results suggest that SA leads to swelling and unfolding of gluten proteins, thereby increasing their interaction potential and dough strength, but simultaneously increasing intermolecular electrostatic repulsive forces. These phenomena lead to the reported changes in dough properties. Together, our results establish SA as an important yeast metabolite for dough rheology.
Food chemistry.Food Chem.2014 May 15;151:421-8. doi: 10.1016/j.foodchem.2013.11.025. Epub 2013 Nov 15.
Succinic acid (SA) was recently shown to be the major pH determining metabolite produced by yeast during straight-dough fermentation (Jayaram et al., 2013), reaching levels as high as 1.6mmol/100g of flour. Here, the impact of such levels of SA (0.8, 1.6 and 2.4mmol/100g flour) on yeastless dough pr
PMID 24423552

Harvesting yeast (Saccharomyces cerevisiae) at different physiological phases significantly affects its functionality in bread dough fermentation.

Rezaei MN1, Dornez E1, Jacobs P1, Parsi A1, Verstrepen KJ2, Courtin CM3.Author information 1Laboratory of Food Chemistry and Biochemistry & Leuven Food Science and Nutrition Research Centre (LFoRCe), Department of Molecular and Microbial Systems, KU Leuven, Kasteelpark Arenberg 20, Box 2463, B-3001 Leuven, Belgium.2VIB Laboratory for Systems Biology & CMPG Laboratory for Genetics and Genomics, KU Leuven, Bio-Incubator, Gaston Geenslaan 1, B-3001 Leuven, Belgium.3Laboratory of Food Chemistry and Biochemistry & Leuven Food Science and Nutrition Research Centre (LFoRCe), Department of Molecular and Microbial Systems, KU Leuven, Kasteelpark Arenberg 20, Box 2463, B-3001 Leuven, Belgium. Electronic address: christophe.courtin@biw.kuleuven.be.AbstractFermentation of sugars into CO2, ethanol and secondary metabolites by baker's yeast (Saccharomyces cerevisiae) during bread making leads to leavening of dough and changes in dough rheology. The aim of this study was to increase our understanding of the impact of yeast on dough related aspects by investigating the effect of harvesting yeast at seven different points of the growth profile on its fermentation performance, metabolite production, and the effect on critical dough fermentation parameters, such as gas retention potential. The yeast cells harvested during the diauxic shift and post-diauxic growth phase showed a higher fermentation rate and, consequently, higher maximum dough height than yeast cells harvested in the exponential or stationary growth phase. The results further demonstrate that the onset of CO2 loss from fermenting dough is correlated with the fermentation rate of yeast, but not with the amount of CO2 that accumulated up to the onset point. Analysis of the yeast metabolites produced in dough yielded a possible explanation for this observation, as they are produced in different levels depending on physiological phase and in concentrations that can influence dough matrix properties. Together, our results demonstrate a strong effect of yeast physiology at the time of harvest on subsequent dough fermentation performance, and hint at an important role of yeast metabolites on the subsequent gas holding capacity.
Food microbiology.Food Microbiol.2014 May;39:108-15. doi: 10.1016/j.fm.2013.11.013. Epub 2013 Dec 1.
Fermentation of sugars into CO2, ethanol and secondary metabolites by baker's yeast (Saccharomyces cerevisiae) during bread making leads to leavening of dough and changes in dough rheology. The aim of this study was to increase our understanding of the impact of yeast on dough related aspects by inv
PMID 24387860

Modified COLD-PCR for detection of minor microorganisms in wine samples during the fermentation.

Takahashi M1, Masaki K2, Mizuno A2, Goto-Yamamoto N2.Author information 1National Research Institute of Brewing (NRIB), 3-7-1 Kagamiyama, Higashi-Hiroshima 739-0046, Japan. Electronic address: m.takahashi@nrib.go.jp.2National Research Institute of Brewing (NRIB), 3-7-1 Kagamiyama, Higashi-Hiroshima 739-0046, Japan.AbstractThe detection of low-abundant microorganism is difficult when in a sample in which a specific microorganism represents an overwhelming majority using polymerase chain reaction (PCR)-based methods. A modified CO-amplification at Lower Denaturation temperature PCR (mCOLD-PCR) method was developed to detect low-abundant microorganisms using a double-strand RNA probe to inhibit the amplification of the sequence of a major microorganism. Combining the mCOLD-PCR and downstream application (e.g., denaturing gradient gel electrophoresis (DGGE) and next-generation sequencing (NGS)), low-abundant microorganisms were detected more efficiently, even when a specific microorganism represents an overwhelming majority of the sample. We demonstrated that mCOLD-PCR-DGGE enabled us to detect Schizosaccharomyces pombe in a model sample coexisting with 10,000 times as many Saccharomyces cerevisiae. When mCOLD-PCR-DGGE was applied in the microbiota analysis of a fermenting white wine, Candida sp. and Cladosporium sp., which were not detected by conventional PCR, were detected. According to the NGS analysis after mCOLD-PCR of a fermenting red wine, the detection ratio of Saccharomyces was decreased dramatically, and the detection ratios of other microorganisms and the numbers of genera detected were increased compared with the conventional PCR. Thus, the application of mCOLD-PCR will reveal comprehensive microbiota of fermented foods, beverages, and so on.
Food microbiology.Food Microbiol.2014 May;39:74-80. doi: 10.1016/j.fm.2013.11.009. Epub 2013 Nov 21.
The detection of low-abundant microorganism is difficult when in a sample in which a specific microorganism represents an overwhelming majority using polymerase chain reaction (PCR)-based methods. A modified CO-amplification at Lower Denaturation temperature PCR (mCOLD-PCR) method was developed to d
PMID 24387855

Japanese Journal

Cre/loxP, Flp/FRT Systems and Pluripotent Stem Cell Lines

Candice G. T. Tahimic,Sakurai Kenji,Aiba Kazuhiro,Nakatsuji Norio
Topics in Current Genetics 23, 189-209, 2013
… coli bacteriophage P1 where it plays a crucial role in the life cycle of P1 while Flp recombinase was originally derived from the 2 μ circle of Saccharomyces cerevisiae and catalyzes recombination between inverted repeats within the 2 μ plasmid. …
NAID 120004873769

Time Dependence of Nonlinear Dielectric Responses in Yeast Cells at Various Concentrations

Mizuyama Kazuaki,Muraji Masafumi
電気学会論文誌. A, 基礎・材料・共通部門誌 132(11), 993-996, 2012-11
NAID 40019483563

Improvement of the growth defect in salt- and ethanol-tolerant yeast mutagenized with error-prone DNA polymerization by using backcross cell fusion

Hayashi Kazukiyo,Yano Shuntaro,Abe Hiroko [他]
Journal of bioscience and bioengineering 114(4), 476478, 2012-10
NAID 40019464320

Related Pictures

★リンクテーブル★

リンク元	「酵母菌属」「酵母類」「サッカロミセス」「サッカロマイセス」「サッカロミセス属」
拡張検索	「Saccharomyces cerevisiae」「Saccharomyces属」「Saccharomyces carlsbergensis」「yeast Saccharomyces cerevisiae」

「酵母菌属」

Saccharomyces
Scientific classification
Domain:	Eukarya
Kingdom:	Fungi
Phylum:	Ascomycota
Subphylum:	Saccharomycotina
Class:	Saccharomycetes
Order:	Saccharomycetales
Family:	Saccharomycetaceae
Genus:	Saccharomyces; (E.C. Hansen 1838) Meyen
Species
	Saccharomyces arboricolus; Saccharomyces bayanus; Saccharomyces boulardii; Saccharomyces bulderi; Saccharomyces cariocanus; Saccharomyces cariocus; Saccharomyces cerevisiae; Saccharomyces chevalieri; Saccharomyces dairenensis; Saccharomyces ellipsoideus; Saccharomyces eubayanus; Saccharomyces exiguus; Saccharomyces florentinus; Saccharomyces kluyveri; Saccharomyces kudriavzevii; Saccharomyces martiniae; Saccharomyces mikatae; Saccharomyces monacensis; Saccharomyces norbensis; Saccharomyces paradoxus; Saccharomyces pastorianus; Saccharomyces spencerorum; Saccharomyces turicensis; Saccharomyces unisporus; Saccharomyces uvarum; Saccharomyces zonatus;