Yeast species

Fig. 3. Comparison of 18 S rRNA sequences from four plant species, yeast, rabbit, and Xenopus. Sequences of a portion of the 3 minor domain of 18 S rRNA are compared. Also shown is a consensus derived from the comparison. Lowercase letters indicate where the sequence differs from the consensus. Numbers correspond to the coordinates for the four plant rRNAs determined in this study. Gaps introduced by sequence alignment are ignored in the numbering.

Besides human SOD, other types of SOD were expressed in organisms different from those of the native species. Yeast SOD from S. cerevisiae was expressed in E. coli using the T7 RNA polymerase expression system (148-150). Cu2Zn2SOD from X. laevis was overex-... 

Mitochondria from maize leaves do in fact respond to a series of strobilurins, but are in this case less sensitive than mitochondria from non-plant species (yeast, Botrytis, rat, house fly) [59]. Note that, generally, inhibition of mitochondrial respiration in plants ( dark respiration ) does not lead to severe undesired influences on plant physiology. 

Interactions of Cactus Species, Yeasts, and Drosophila Benzylisoquinoline Alkaloids... 

The agents that induce superficial fungal infections include dermatophytes (responsible for tinea, or ringworm) and Candida species yeasts. 

The specificity of conduritol B epoxide is such that -glucosidases from widely differing sources have been found to react with loss of enzymic activity from various Aspergillus species, > yeast, snail Helix pomatia) sweet almonds, and mammals. The only exceptions have been the / -glucosidases from garbanzo plants Cicer arietum L.) and from Alocasia macrorrhiza The only other enzymes that have been found to be covalently inhibited are a-glucosidase from yeast Saccharo-myces cerevisiae) and the sucrase-isomaltase complex from rabbit small intestine. ... 

In addition to its presence in fmits, S(—)-malic acid has been found in cultures of a variety of microorganisms including the aspergiUi, yeasts, species of Sekrotinia, and Penicillium brevicompactum. Yields of levorotatory malic acid as high as 74% of theoretical have been reported. Iron, manganese, chromium, or aluminum ions reportedly enhance malic acid production. S(—)-Mahc acid is involved in two respiratory metaboHc cycles the Krebs tricarboxylic acid... 

In the acid hydrolysis process (79—81), wood is treated with concentrated or dilute acid solution to produce a lignin-rich residue and a Hquor containing sugars, organic acids, furfural, and other chemicals. The process is adaptable to all species and all forms of wood waste. The Hquor can be concentrated to a molasses for animal feed (82), used as a substrate for fermentation to ethanol or yeast (82), or dehydrated to furfural and levulinic acid (83—86). Attempts have been made to obtain marketable products from the lignin residue (87) rather than using it as a fuel, but currently only carbohydrate-derived products appear practical. 

Yeasts belonging to Basidior cetes form external spores. ia.yiscomjcetes sexual reproduction occurs with the formation of spores in a cell that serves as a spore sac or ascus. Generally four, but sometimes eight or more, spores are formed in each ascus. This is sometimes reflected in the species name, ie,... 

The elemental and vitamin compositions of some representative yeasts are Hsted in Table 1. The principal carbon and energy sources for yeasts are carbohydrates (usually sugars), alcohols, and organic acids, as weU as a few other specific hydrocarbons. Nitrogen is usually suppHed as ammonia, urea, amino acids or oligopeptides. The main essential mineral elements are phosphoms (suppHed as phosphoric acid), and potassium, with smaller amounts of magnesium and trace amounts of copper, zinc, and iron. These requirements are characteristic of all yeasts. The vitamin requirements, however, differ among species. Eor laboratory and many industrial cultures, a commercial yeast extract contains all the required nutrients (see also Mineral nutrients). 

Beer taste can be spoiled by contaminating bacteria or yeasts. The most common bacteria are lactic and acetic acid producers and T ymomonas. Wild yeasts can be anything other than the intended strain S. uvarum is considered a contaminant of ale fermentations and S. cerevisiae a contaminant of lager fermentations. The common wild yeast contaminants are S. diastaticus and species of Picbia, Candida and Brettanomjces. It may be noted that the flavor of beer may be improved by the ability of yeast to adsorb bitter substances extracted from hops, such as humulones and isohumulones. 

Wine. The earliest known wines were made in Iran about 5400—5000 BC (25). The species of grape used is unknown and may have been either the wild grape Fitis viniferus sylvestris or a cultivated precursor of the modem wine grape V. viniferus viniferus. The source of the yeast used, and the procedures used are completely unknown. In modem times, grapes (about 21—23% sugar) are pressed the liquid must is either separated and allowed to settle for 1—2 days (for white wines) before inoculation with yeast, or the whole mass is dkectly inoculated with yeast (for red wines). In either case, while the initial fermentation takes place, the carbon dioxide formed by fermentation excludes ak and prevents oxidation. White wines are transferred to a second fermentor (racked) near the end of fermentation and kept isolated from the ak while solids, including yeast, settle out, a process that requkes about six... 

Many foods such as alcohoHc beverages, pickles, cheese, and fish sauce are preserved by fermentation. Spontaneous fermentations by mixed populations of yeasts and bacteria are normally iavolved. Preservation results from a lowering of pH or the formation of ethanol. Yeasts do not produce antibiotics, although isolates of a number of species produce a toxia ("killer factor") lethal to other yeasts. 

Indications are mycoses of the skin, hair, and nails due to species of Trichophyton Tpidermophyton floccosum and Microsporum. Yeasts and bacteria are not sensitive. Griseofulvin has a very weak effect against Side effects may include headaches and gastrointestinal disorders, but they are usually only... 

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