Yeasts, classification

Lewin A., Morimoto R., Rabinowitz M. (1978). Restriction enzyme analysis of mitochondrial DNAs of petite mutants of yeast classification of petites, and deletion mapping of mitochondrial genes. Mol. Gen. Genet. 163 257-275. 

For yeasts, classification to the genus level requires demonstration of the presence or absence of a sexual phase in the life cycle. Sexual spores, called ascospores, are produced and upon germination yield the vegetative budding yeast. The absence of sexual spores during the life cycle results in the yeast being classified as the anamorph or asexual ( imperfect ) form, whereas success in demonstrating the presence of sexual... 

The latest yeast classification (Barnett etal., 2000) is based on recent advances in genetics and molecular taxonomy—in particular, DNA recombination tests reported by Vaughan Martini and Martini (1987) and hybridization experiments... 

Boekhout, T., Kurtzman, C. P. Principles and methods used in yeast classification, and overview of currently accepted genera. In Non conventional yeasts in Biotechnology, A Handbook, Wolf, K., Ed., Springer-Verlag Berlin, 1996, pp. 1-80. 

G. I. De Becze, Classification of Yeasts, WaHerstein Laboratories Communications, 1958—1963. 

Fungi are microscopic nonphotosynthetic plants which include in their classification yeast and molds. Yeasts have a commercial value as they are used for fermentation operations in distilling and brewing. When anaerobic conditions exist, yeasts metabolize sugar, manufacturing alcohol from the synthesis of new cells. Alcohol... 

The ability to grow at the expense of 4-hydroxy- and 3,4-dihydroxybenzoate has been nsed for the classification of medically important yeasts inclnding Candida parapsilosis (Cooper and Land 1979). This organism degrades these snbstrates by oxidative decarboxylation, catalyzed by a flavoprotein monooxygenase (Eppink et al. 1997). 

Allen, J. Broadhurst, H. M. Heald, J. K. Rowland, J. J. Oliver, S. G Kell, D. B. High-throughput classification of yeast mutants for functional genomics using metabolic footprinting. Nat. Biotechnol. 2003, 21, 692-696. 

Ceramidases are enzymes that cleave the N-acyl linkage of Cer into SPH and free fatty acid. They are an emerging class of enzymes composed of multiple isoforms. Historically, these isoforms have been classified as acid, neutral or alkaline, based on the pH optimum of their activities although some isoforms show activity in a broad range. With the recent cloning of several isoforms from yeast, bacteria, and mammals, a genetical distinction and classification of these enzymes can now be employed. 

The equivalent cyclins in yeast have a different classification and are shown in Table 13.1. 

Yeasts, along with the algae, lichens, and other fungi, are known as thallophytes, a term which means they are undifferentiated plants or ones which do not have separate roots, stems, and leaves. Wine yeasts, along with most brewers, distillers, and bakers yeasts, are classed in the genus Saccharomyces or sugar fungus. The classification of yeasts is based on microscopic observation of their shape and forms, the way... 

The classification presented here is based upon consistency brought about by differences in moisture content (soft, semisoft, hard, very hard), the manner of ripening (bacteria, mold, yeast, surface or interior microorganisms, combinations or unripened), the method by which the curd is produced (acid or coagulating enzymes, or by acid and high heat, or combinations), and the type of milk employed (National Dairy Council 1979). 

Microorganisms are microscopic plants and animals. In relation to their presence as cooling water contaminants, we generally mean the mixed populations of bacteria, fungi (which includes yeasts), phytoplankton (algae), and zooplankton commonly found. Basic classifications and descriptions of microorganisms are discussed in the following sections. 

This example inspired searches for radiation sensitive mutants in yeast. The way was led by Nakai and Matsumoto (1967) who isolated one mutant, UV which was very sensitive to ultraviolet and a second, Xj sensitive to X-rays. They went one step further than isolation and survival curves by making the double-mutant and showing that like double mutants of recA and uvr A in E. coli it was much more sensitive to UV than either single mutant alone. This was the first demonstration of the existence of more than one type or pathway of DNA repair of UV damage in yeast, and inspired the later work of Game and Cox (1972 1973 1974), Brendel and Haynes (1973) and Louise Prakash (1993) in the genetic analysis of pathways of repair in yeast. This led to the classification of the many mutant loci into epistasis groups, which are defined as those mutants which, when combined in the same strain, are no more UV-sensitive than the most sensitive of the two when alone. 

By calculating an average Raman spectrum from a line scan over the long axis of yeast cells a differentiation of single yeast cells on a species and strain level can be performed [110, 111]. The application of Raman spectroscopy in combination with a supervised classification method allows for the identification of single yeast cells in a large data set [69]. 

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