Characterization of killer-resistant strains of Saccharomyces cerevisiae isolated from spontaneous fermentations

Cansado, José; Barros‐Velázquez, Jorge; Calo, Pilar; Sieiro, Carmen; Longo, Elisa; Villa, Tomás G.

doi:10.1016/0378-1097(92)90356-s

Cited by 5 publications

(7 citation statements)

References 20 publications

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“…In this study it was observed that the killer response seems to be race-specific and that the best flor yeasts (S. cerevisiae (beticus) and S. cerevisiae (cheresiensis)) ( Table 5) are resistant to both K, and K, killer toxins (except B16, which was K, sensitive), although they are nonproducers (Table 6). In line with these results it has been reported that the inability to produce killer toxins by resistant strains is favoured by an increase in fermentative capacity (Cansado et al, 1992).…”

Section: Discussionsupporting

confidence: 67%

Physiological and molecular characterization of flor yeasts: Polymorphism of flor yeast populations

Martínez¹,

Codón

Pérez³

et al. 1995

Yeast

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Yeast strains which form velum on the surface of Sherry wine during the aging process have been isolated and characterized. According to their metabolic and molecular features most of the yeasts that were isolated belong to different races of Saccharomyces cerevisiae (beticus, cheresiensis, montuliensis and rouxii). Due to the conditions under which these yeasts were isolated, all strains have in common the capacity to develop a film as an adaptive mechanism which allows them to grow and survive in 15.5% vol. ethanol. All strains were prototrophs for amino acids and most vitamins but they gave different responses to the killer factor. However, whereas their physiological features were similar, they showed a great heterogeneity with regards to the nuclear and mitochondrial genome (mtDNA): DNA content per cell was quite variable (1.3 to 2n), electrophoretic karyotypes of nuclear genomes indicated a main pattern with some variations, and polymorphism shown by the mtDNA was very high. Under extreme conditions such as Sherry wine with 15.5% vol. ethanol, no fermentable sugar and an exclusively oxidative metabolism, cells hardly grow and the maintenance of a live population depends on survival and respiration, which in turn depend on the mtDNA. At the same time these environmental conditions are mutagenic for the mtDNA, causing an increase in variation. Thus, the polymorphism observed might reflect the enormous variability induced by the ethanol followed by the selection of those mtDNA sequences which make the mitochondria metabolically active under these conditions.

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Section: Discussionsupporting

confidence: 67%

Physiological and molecular characterization of flor yeasts: Polymorphism of flor yeast populations

Martínez¹,

Codón

Pérez³

et al. 1995

Yeast

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“…Interestingly however, chromosome DNA pulsed field gel electrophoresis of 26 killerresistant N (neutral) wine strains of S. cerevisiae revealed that 92 % were derivatives of K2 killer toxin producing strains that had lost the ability to produce active toxin (16). Similar results were obtained in a Bordeaux winery (17) where it was observed that one karyotype of S. cerevisiae was stable and dominant in different wine vessels over a 2-year period.…”

Section: Among Yeastssupporting

confidence: 68%

Fungal interactions in food fermentations

Nout¹

1995

Can. J. Bot.

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Fermented foods are of importance worldwide. Most are prepared under nonsterile conditions using mixed cultures, either deliberately or unavoidably. Fungal mixed cultures show interactive relations at various levels. In this paper, inhibitory effects among fungi owing to competition, formation of organic acids, toxic proteins, and mycotoxins are discussed. In addition, fungi show inhibitory effects towards bacteria and vice versa, through pH changes, and excretion of organic acids, antibiotics, peptides, etc. Stimulatory interactions among fungi and between fungi and bacteria relate mainly to carbon and nitrogen metabolism, and they play an important role in the inherent stability of mixedculture systems maintained by enrichment techniques. Better understanding of natural mixed-culture fermentations has evolved into the development of the concept of cocultivation employing compatible microbial strains of complementary metabolic ability. Especially in the area of direct conversion of complex carbohydrates (e.g., starch, inulin, or lignocellulosic matter into ethanol), cocultivation has much to offer. Genetic modification of starter organisms offers opportunities to improve, for example, their ability to degrade substrate with a minimum of catabolite repression, and produce final products of superior quality. This is illustrated by recent recombinant DNA constructs for alcoholic fermentations.RCsurnC : Les aliments ferment& sont importants partout dans le monde. La plupart sont prCparCs sous des conditions non-sttriles, en utilisant des cultures mixtes, soit de f a~o n dCLibirCe soit de f a~o n inCvitable. Les cultures fongiques mixtes montrent des relations interactives B diffirents niveaux. Dans sa revue, l'auteur discute les effets inhibiteurs chez les champignons dus B la cornpitition, ? i la formation d'acides organiques, d'antibiotiques et de mycotoxines. De plus, les champignons montrent des effets inhibiteurs envers les bacttries et vice versa, par 1'intermCdiaire de changement du pH et I'excrCtion d'acides organiques, d'antibiotiques, de peptides etc. Les interactions de stimulation entre champignons et entre champignons et bactCries sont principalement reliCes au mttabolisme du carbone et de l'azote, et elles jouent un rBle important dans la stabilitC inherente des systbmes de cultures mixtes maintenues par des techniques d'enrichissement. Une meilleure comprChension des fermentations naturelles mixtes s'est dtveloppte avec le dCveloppement du concept de co-culture impliquant des souches microbiennes compatibles posstdant des dispositions mCtaboliques compltmentaires. Surtout dans les systkmes impliquant la conversion directe des glucides (p. ex., l'amidon, l'inuline ou la matibre ligno-cellulosique en tthanol), la co-culture a beaucoup B offrir. La modification gCnCtique des organismes de dCpart offre des occasions d'amCliorer par example, leur capacitC B dCgrader le substrat avec un minimum de rtpression catabolique, et des produits finis de qualit6 suptrieure. Ce propos est illustrt par la construction...

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“…Recently, interest in the development of bacteriocins as food preservatives (14) and in the use of the killer factors for industrial applications has increased (7,13,29,30). However, the role that killer activity may have as a mechanism of antagonism among yeasts in natural environments is not clear, and the conditions governing their behavior in various niches are mostly unknown.…”

mentioning

confidence: 99%

“…However, the role that killer activity may have as a mechanism of antagonism among yeasts in natural environments is not clear, and the conditions governing their behavior in various niches are mostly unknown. In spite of this lack of knowledge, the use of killer toxins to control yeast populations during fermentations has been postulated for beer and wine (7).…”

mentioning

confidence: 99%

(1→6)-β-d-Glucan as Cell Wall Receptor forPichia membranifaciensKiller Toxin

Santos

Marquina

Leal

et al. 2000

Appl Environ Microbiol

111

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Cell walls determine the shape of fungal cells and are essential for their integrity. They consist mainly of carbohydrates, some free and some linked to protein. The main components of the yeast cell wall are a (133)-␤-D-glucan (50%) that also contains some (136)-␤-linked branches (5%) (11) and a mannoprotein, most of which is carbohydrate. A (136)-␤-D-glucan, also containing some (133)-␤-linked branches (14%), is a relatively minor constituent (15%), and chitin (0.6 to 9%) is present at an even lower level (18). The latter is concentrated in the bud-scar region (18). The role of cell surface polysaccharides as receptors for proteins in many cell events is widely accepted, but the mechanism of their action is poorly understood. As well as acting as receptors for bacteria, viruses, and toxins, surface polysaccharides may be involved in cell interactions, such as cell associations, distribution, and turnover (15).Killer yeasts act on sensitive yeasts by liberating killer toxins that are either proteins or glycoproteins. The K1 killer toxin of Saccharomyces cerevisiae acts in two steps (20). First, the toxin is adsorbed by a glucan of the cell wall. Then, the toxin is bound to a receptor in the cell membrane, damaging the membrane and releasing K ϩ , ATP, and other metabolites and destroying the pH gradient of the membrane (8). Binding of toxin to the wall receptor appears to be a necessary prelude to cell killing (1, 4). Previous workers (1, 5) defined a specific cell wall receptor for killer toxin by measuring binding of toxin to sensitive cells and to resistant mutants with defective receptors. The receptor, probably a polysaccharide or glycoprotein, was solubilized from yeast cell walls by an endo-(133)-␤-D-glucanase action and is heat and pronase resistant but periodate sensitive (1).Various primary receptors for other killer toxins have been reported. (133) (33), and chitin is a receptor for Kluyveromyces lactis killer toxin (41). Thus, any of the principal components of the cell wall could be the primary receptor for a killer toxin.The phenomenon of killer activity in yeast was originally observed with Saccharomyces (23) and was later found in other genera (19,27). Recently, interest in the development of bacteriocins as food preservatives (14) and in the use of the killer factors for industrial applications has increased (7,13,29,30). However, the role that killer activity may have as a mechanism of antagonism among yeasts in natural environments is not clear, and the conditions governing their behavior in various niches are mostly unknown. In spite of this lack of knowledge, the use of killer toxins to control yeast populations during fermentations has been postulated for beer and wine (7).In previous work (22,25,26), members of this group found that Pichia membranifaciens, the dominant species of yeast isolated from spontaneously fermenting olive brines, had killer characteristics. We also found that sodium chloride, in concentrations similar to those found in the brines, enhanced the apparent toxicity of...

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Characterization of killer-resistant strains of Saccharomyces cerevisiae isolated from spontaneous fermentations

Cited by 5 publications

References 20 publications

Physiological and molecular characterization of flor yeasts: Polymorphism of flor yeast populations

Physiological and molecular characterization of flor yeasts: Polymorphism of flor yeast populations

Fungal interactions in food fermentations

(1→6)-β-d-Glucan as Cell Wall Receptor forPichia membranifaciensKiller Toxin

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