Yeast species and strains

Romano P, Riore C, Paraggio M, Caruso M, Capece A (2003b) Runction of yeast species and strains in wine flavour. International Journal of Food Microbiology, 86, 169-180. 

Ockert, P.H.A. and Kock, J.L.F. 1989. Differentiation of yeast species, and strains within a species, by cellular fatty acid analysis. 1. Application of an adapted technique to differentiate between strains of Saccharomyces cerevisiae. J. Microbiol. Methods 10, 9-23. 

Biodiversity and characterization of yeast species and strains from a brewing environment... 

Augustyn, O.P.H., J.L.F. Kock, and D. Ferreira. 1992. Differentiation between yeast species and strains within species by cellular fatty acid analysis 5. A feasible technique Sys. Appl. Microbiol. 15 105—115. 

Table 3 Susceptibility of Yeast Species and Bacterial Strains from Pea Seedlings Against the Heterocyclic Nonprotein Amino Acid P-I.soxylinonyl-Alanine (PlA) ...

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]. 

In addition to the choice of yeast strain, the method of inoculation can be used to modulate wine flavour in ways not readily achievable with conventional yeasts, which are typically used in monoculture. A combination of alternative yeast species and inoculation strategies can lead to wines with very different chemical and flavour profiles, such as greater complexity and diversity of flavours, and enhanced mouth-feel and persistence of flavour (Table 8D.4). 

Soles, R. M., Ough, C. S., Kunkee, R. E. (1982) Ester concentration differences in wine fermented by various species and strains of yeasts. American Journal of Enology and Viticulture, 33, 94-98. 

The information in Sections VI to XI depends on the study of relatively few species and strains, but, in this Section, an attempt will be made to provide some generalizations, applicable to most yeasts, regarding the way in which they utilize sugars. These generalizations must necessarily be partly speculative and, as such, must eventually be subjected to experimental verification by the enzymic examination of selected yeasts. It is hoped that this Section will stimulate such investigations. 

Pichia stipitis. P. stipitis is the most effective natural yeast for the conversion of xylose to ethanol. This yeast species shares many characteristics with its close relative, C. shehatae. Toivola et al. [90] performed a systemic screening program with type strains of some 200 yeast species and identified P. stipitis as one of the yeast species that produces ethanol from xylose. There are many studies that have explored the property of this yeast in relation to its oxygen requirement, ethanol tolerance, enzyme cofactor s balance, etc. According to the reported literature [91,92], ethanol production from xylose by P stipitis exhibits the following characteristics ... 

If a particular yeast strain is chosen for the production of single cell protein, it is desirable to grow the chosen microbe on this same yeast to induce lytic enzyme production. The rationale for this is the considerable variation in cell wall composition between yeast species, and the most effective lytic enzyme complex is obtained by using the same strain as enzyme inducer. 

Lethal effects of a high fermentation temperature are often thought to result from the effect of temperature alone. However, inhibition is also the result of intracellular accumulations of ethanol. Temperature tolerance of yeast varies with species and strain and reflects intrinsic and extrinsic properties of the growth medium. Generally, yeast viability in alcoholic media subsides at temperatures near 35°C (95°F). 

Long-chain fatty acids. Small amounts of 20 0, 22 0 and 24 0 have been recorded in a few yeasts but are probably present as trace continuents in many species. Polyunsaturated, long-chain fatty adds have usually been only recorded in a few instances Cottrell (1989) produced evidence for the occurrence of di-homo-y-linolenic acid (20 3) and arachidonic acid (20 4) in the yeast Dipodascopsis uninucleata (Botha et al., 1992). However, in a detailed examination of a number of related yeasts, Botha et al. (1992) did not find the presence of even traces of 20 4 in any of nearly 50 species and strains that were examined. 

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