The occurrence of killer character in yeasts of various genera

Philliskirk, G.; Young, Tom

doi:10.1007/bf02565046

Cited by 153 publications

(83 citation statements)

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“…Non-Saccharomyces yeasts exhibiting killer activity were first reported by Philliskirk and Young (1975) Wickner (1979) reported that Torulopsis glabrata ATCC15126 also secretes a killer toxin, named K11. Non-Saccharomyces killer toxins originate either from linear dsDNA plasmids or chromosomes (Marquina et al, 2002;Liu et al, 2013), with the notable exception of the killer toxins of H. uvarum and Z. bailii, which originate from virus-like particles (Schmitt & Neuhausen, 1994), similar to those of S. cerevisiae.…”

Section: Killer Toxins Secreted By Non-saccharomyces Yeastsmentioning

confidence: 99%

Non-Saccharomyces Killer Toxins: Possible Biocontrol Agents Against Brettanomyces in Wine?

Mehlomakulu

Setati

Divol

2015

SAJEV

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Red wine spoiled by the yeast Brettanomyces bruxellensis is characterised by off-odours commonly described as horse sweat, phenolic, varnish and band-aid. The growth of this yeast in wine is traditionally controlled by the use of sulphur dioxide (SO 2 ). However, the concentration of SO 2 , the pH of the wine, the presence of SO 2 -binding chemical compounds in the wine, as well as the strain of B. bruxellensis, determine the effectiveness of SO 2 . Other chemical preservatives have been tested, but are not much more efficient than SO 2 , and methods used to clean barrels are only partially effective. Filtration of wine and the use of electric currents/fields are also reported to alter the physical and sensory properties of wine. In this context, alternative methods are currently sought to achieve full control of this yeast in wine. Killer toxins have recently been proposed to fulfil this purpose. They are antimicrobial compounds secreted by Saccharomyces and non-Saccharomyces yeasts, displaying killer activity against other yeasts and filamentous fungi. They are believed to play a role in yeast population dynamics, and this killer phenotype potentially could be exploited to inhibit the growth of undesired microorganisms within a microbial ecosystem such as that occurring in wine. In this review, non-Saccharomyces killer toxins are described and their potential application in inhibiting B. bruxellensis in wine is discussed in comparison to other tried methods and techniques.

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Section: Killer Toxins Secreted By Non-saccharomyces Yeastsmentioning

confidence: 99%

Non-Saccharomyces Killer Toxins: Possible Biocontrol Agents Against Brettanomyces in Wine?

Mehlomakulu

Setati

Divol

2015

SAJEV

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“…Killer activity was assayed by the methods described in various earlier papers on the killer phenomenon (8,16). YM agar buffered to pH 4.2 with 0.05 M citrate buffer and containing 0.003% (wt/vol) methylene blue was used as the assay medium.…”

Section: Samples Of Necrotic Opuntia Tissue Yielding Pichia Barkerimentioning

confidence: 99%

Pichia barkeri, a New Yeast Species Occurring in Necrotic Tissue of Opuntia stricta

Phaff

Starmer

Tredick-Kline

et al. 1987

International Journal of Systematic Bacteriology

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We describe Pichiu barkeri, a new cactophilic yeast species occurring in necrotic tissue of Opuntia stricta in New South Wales, Australia, and on several islands in the Caribbean Sea. The new species is homothallic and appears to occur in nature in the haploid state. After conjugation between a mother cell and a bud, four hat-shaped spores are produced that are rapidly released from the ascus. The range of guanine-plus-cytosine contents for the nuclear deoxyribonucleic acids of 22 strains is 35.7 to 36.6 mol% (average, 36.1 mol%; standard deviation, 0.2 mol%). The type strain of P. barkeri is strain UCD-FST 83-994.3 (ATCC 64111, CBS 7256) isolated at Discovery Bay, Jamaica.The rotting stems and cladodes of Opuntia species are specific habitats for a diversity of cactus-specific yeast species (1,2,7,11). During surveys of yeasts associated with rots of Opuntia species in Australia (1, 2), we isolated a number of strains that were initially identified by the system of Lodder (5) as Pichia kluyveri. Because P. kluyveri had been recovered only rarely in earlier surveys of columnar cacti (12), we initially concluded that these strains might have converged on the P . kluyveri phenotype or might be fermentative forms of Pichia cactophila. Subsequent characterization by molecular criteria (6) showed that the isolates in question differed from P. kluyveri in having a nuclear deoxyribonucleic acid (DNA) guanine-plus-cytosine (G + C) content approximately 6 mol% higher than that of P. kluyveri (-36 versus -30 mol%), virtually precluding conspecificity (6). Ensuing experiments, using the technique of DNA-DNA hybridization, provided additional evidence that the Australian isolates represented a different species, although retaining a distant relationship with P. kluyveri. DNA-DNA hybridization experiments also showed that the Australian isolates are distinct from P. cactophila, which has a similar base composition (-36 mol% G+C). During subsequent explorations of the yeast floras associated with cacti occurring on various islands in the Caribbean Sea, we isolated several additional strains of the new species, Pichia barkeri, also associated with necrotic tissue of Opuntia stricta.

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“…Killer toxins were first discovered in Saccharomyces cerevisiae by Makower & Bevan (1963) and they have since been found in numerous other yeast genera (Philliskirk & Young, 1975;Stumm et al, 1977;Rosini, 1983Rosini, , 1985Starmer et al, 1987). Through the following years, killer yeasts and their toxins found applications in several fields.…”

Section: Introductionmentioning

confidence: 99%

Kluyveromyces phaffii killer toxin active against wine spoilage yeasts: purification and characterization

et al. 2004

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The killer toxin secreted by Kluyveromyces phaffii (KpKt) is active against spoilage yeast under winemaking conditions and thus has potential applications in the biocontrol of undesired micro-organisms in the wine industry. Biochemical characterization and N-terminal sequencing of the purified toxin show that KpKt is a glycosylated protein with a molecular mass of 33 kDa. Moreover, it shows 93 % and 80 % identity to a b-1,3-glucanase of Saccharomyces cerevisiae and a b-1,3-glucan transferase of Candida albicans, respectively, and it is active on laminarin and glucan, thus showing a b-glucanase activity. Competitive inhibition of killer activity by cell-wall polysaccharides suggests that glucan (b-1,3 and b-1,6 branched glucans) represents the first receptor site of the toxin on the envelope of the sensitive target. Flow cytometry analysis of the sensitive target after treatment with KpKt and K1 toxin of S. cerevisiae, known to cause loss of cell viability via formation of pores in the cell membrane, suggests a different mode of action for KpKt. INTRODUCTIONKiller toxins were first discovered in Saccharomyces cerevisiae by Makower & Bevan (1963) and they have since been found in numerous other yeast genera (Philliskirk & Young, 1975; Stumm et al., 1977;Rosini, 1983Rosini, , 1985Starmer et al., 1987). Through the following years, killer yeasts and their toxins found applications in several fields. For example, killer yeasts have provided an interesting model for studying the mechanisms involved in the processing and secretion of extracellular proteins, and the identification of killer toxin receptors on the envelope of sensitive targets has helped in the elucidation of the structure and function of the yeast cell wall. Killer yeasts have been used to combat contaminating wild yeasts in the food and fermentation industries, and to control wooddecay basidiomycetes and plant-pathogenic fungi (Young, 1987; Boone et al., 1990;Palpacelli et al., 1991, van Vuuren & Jacobs, 1992Walker et al., 1995). In the medical field, these yeasts have been used in the biotyping of pathogenic yeasts and yeast-like fungi (Morace et al., 1989;Boeckhout & Scorzetti, 1997;Buzzini & Martini, 2001), and in the development of novel antimycotics for the treatment of human and animal fungal infections Seguy et al., 1998; Conti et al., 2002;Schmitt & Breinig, 2002).Recently, it has been shown that Kluyveromyces phaffii (since reclassified as Tetrapisispora phaffii) (Ueda-Nishimura & Mikata, 1999) produces a killer toxin (KpKt) that is active on wine spoilage yeasts (Ciani & Fatichenti, 2001). KpKt has an extensive anti-Hansenispora/Kloeckera activity under winemaking conditions and, therefore, is of particular interest for its potential application as an antimicrobial agent in the wine industry (Ciani & Fatichenti, 2001). At present, the inhibition of wild spoilage yeast at the prefermentative stage is achieved by the addition of SO 2 to freshly pressed must. This antiseptic agent, which has been shown to have a toxic action on humans, is also r...

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The occurrence of killer character in yeasts of various genera

Cited by 153 publications

References 9 publications

Non-Saccharomyces Killer Toxins: Possible Biocontrol Agents Against Brettanomyces in Wine?

Non-Saccharomyces Killer Toxins: Possible Biocontrol Agents Against Brettanomyces in Wine?

Pichia barkeri, a New Yeast Species Occurring in Necrotic Tissue of Opuntia stricta

Kluyveromyces phaffii killer toxin active against wine spoilage yeasts: purification and characterization

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