Yeast native yeasts

Heering HA, Wiertz FGM, Dekker C, de Vries S. 2004. Direct immobilization of native yeast Iso-1 cytochrome c on bare gold Fast electron relay to redox enzymes and zeptomole protein-film voltammetry. J Am Chem Soc 126 11103-11112. 

Fig. 1. The testosterone 6j8-hydroxylase activity (expressed as turnover number) for cDNA-expressed CYP3A4 using yeast, bacteria and mammalian cell systems. Yeast-based expression with coexpressed human cytochrome P450 reductase and human cytochrome or native, yeast cytochrome P450 reductase and cytochrome bs (Peyronneau et al., 1992). E. co/i-GSH E. co/i-based expression where the enzyme was purified and reconstituted with and without the addition of glutathione (Gillam et al., 1993). Human lymphoblast-based expression with endogeneous cytochrome P450 reductase (Crespi et al., 1991a) and with coexpression of cytochrome P450 reductase cDNA (C. Crespi, unpublished observation). Vaccinia virus (vv)/HepG2 cell expression data from Buters et al. (1994).

Fig. 17. Visible absorption spectra of partially substituted cobalt yeast alcohol dehydrogenase, (Co, Zn)-ADH, and native yeast alcohol dehydrogenase, (Zn-ADH), respectively. Enzyme concentration, approx. 0.35 mM. From Curdel and Iwatsubo (128)...

In the alcoholic fermentation of juice to wine, SO2 is added at the crushers at the rate of about one pound per one thousand gallons. Pectic enzymes may be added to increase juice yields and clarity. The fermentation is conducted with the native yeast of the grape or various pure culture strains of Saccaromyces cerevisiae. Whether or not yeast cultures are added depends on the quality of the grapes and the winemaker s preferences. Dehydrated wine yeast is in general use at the beginning of the crushing season. 

Native yeasts—o—Milk prot + treh —a—Maltose —Lactose —o— Trehalose... 

Belancic, A., Gunata, Z., Vallier, M.J., Agosin, E. (2003). (i-glucosidase from the grape native yeast Debaryomyces vanriji Purification, characterization and its effect on monoterpene concentration of a Muscat grape juice. J. Agric. Food Chem., 51, 3083-3091. 

Goldfarb, A. (1994) Wild or natural, native yeasts have a role in modem winemaking. Wine and Vines, 75, 27-30. 

Variants have also been described for other native yeast prions [PIN1 [99] and [URE3] [103], as well as for chimeric prions comprising the Sup35 PrD from Saccharomyces species other than cerevisiae, fused to the S. cerevisiae C-terminal region [104,105]. As with the [/ S/+] variants, these other yeast prion variants show differences in the relative levels of soluble prion protein and in the stability of the prion during cell division. 

Libkind, D., and van Broock, M. 2006. Biomass and carotenoid pigment production by Patagonian native yeasts. World JMicrobiol Biotechnol 22 687-692. 

Like some native yeast and acetic acid bacteria, native LAB may not be killed during primary processing and alcoholic fermentation. As some of these may be spoilage strains, they may represent a significant carry-through threat, in that if future conditions permit, they may develop into dense populations. 

In most cases, the problem stemmed from fermentation of high-pH (>3.5) musts without prefermentation additions of SO2 (Edwards, 1996). Secondary processing variables also occasionally linked to the infection included extended cold soaking prior to inoculation and/or reliance on native yeast fermentations. 

Processing protocol may differentially effect survival, growth, and potentially numerical dominance of one yeast over another (see Chapters 4 and 5). Due to undefined contributions of native yeasts, most winemakers rely on the use of commercial active-yeast starters. When added to must/... 

The contributions to wine character by native yeast fermentations are not restricted to flavor and bouquet. The extended lag phase before the onset of vigorous fermentation is likely, also important. As noted by Zoecklein et al. (1995), reaction of oxygen with anthocyanins and other phenols, in the absence of ethanol, is thought to enhance color stability (in resultant red wines) as well as accelerating phenol polymerization. 

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