scholarly journals New Cytoplasmic Virus-Like Elements (VLEs) in the Yeast Debaryomyces hansenii

Toxins ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 615
Author(s):  
Xymena Połomska ◽  
Cécile Neuvéglise ◽  
Joanna Zyzak ◽  
Barbara Żarowska ◽  
Serge Casaregola ◽  
...  
Keyword(s):  
Genetic Information ◽  
Yeast Species ◽  
Debaryomyces Hansenii ◽  
Penicillium Roqueforti ◽  
Culture Collections ◽  
Killer Activity ◽  
Killer Toxins ◽  
Genes Encoding ◽  
High Conservation ◽  
Linear Dsdna

Yeasts can have additional genetic information in the form of cytoplasmic linear dsDNA molecules called virus-like elements (VLEs). Some of them encode killer toxins. The aim of this work was to investigate the prevalence of such elements in D. hansenii killer yeast deposited in culture collections as well as in strains freshly isolated from blue cheeses. Possible benefits to the host from harboring such VLEs were analyzed. VLEs occurred frequently among fresh D. hansenii isolates (15/60 strains), as opposed to strains obtained from culture collections (0/75 strains). Eight new different systems were identified: four composed of two elements and four of three elements. Full sequences of three new VLE systems obtained by NGS revealed extremely high conservation among the largest molecules in these systems except for one ORF, probably encoding a protein resembling immunity determinant to killer toxins of VLE origin in other yeast species. ORFs that could be potentially involved in killer activity due to similarity to genes encoding proteins with domains of chitin-binding/digesting and deoxyribonuclease NucA/NucB activity, could be distinguished in smaller molecules. However, the discovered VLEs were not involved in the biocontrol of Yarrowia lipolytica and Penicillium roqueforti present in blue cheeses.

The ecological role of killer yeasts in natural communities of yeasts

1987 ◽  
Vol 33 (9) ◽  
pp. 783-796 ◽  
Author(s):  
William T. Starmer ◽  
Philip F. Ganter ◽  
Virginia Aberdeen ◽  
Marc-Andre Lachance ◽  
Herman J. Phaff
Keyword(s):  
Yeast Species ◽  
Kluyveromyces Lactis ◽  
Killer Toxin ◽  
Toxin Production ◽  
Killer Activity ◽  
Killer Yeast ◽  
Killer Toxins ◽  
Naturally Occurring ◽  
Pichia Kluyveri

The killer phenomenon of yeasts was investigated in naturally occurring yeast communities. Yeast species from communities associated with the decaying stems and fruits of cactus and the slime fluxes of trees were studied for production of killer toxins and sensitivity to killer toxins produced by other yeasts. Yeasts found in decaying fruits showed the highest incidence of killing activity (30/112), while yeasts isolated from cactus necroses and tree fluxes showed lower activity (70/699 and 11/140, respectively). Cross-reaction studies indicated that few killer-sensitive interactions occur within the same habitat at a particular time and locality, but that killer-sensitive reactions occur more frequently among yeasts from different localities and habitats. The conditions that should be optimal for killer activity were found in fruits and young rots of Opuntia cladodes where the pH is low. The fruit habitat appears to favor the establishment of killer species. Killer toxin may affect the natural distribution of the killer yeast Pichia kluyveri and the sensitive yeast Cryptococcus cereanus. Their distributions indicate that the toxin produced by P. kluyveri limits the occurrence of Cr. cereanus in fruit and Opuntia pads. In general most communities have only one killer species. Sensitive strains are more widespread than killer strains and few species appear to be immune to all toxins. Genetic study of the killer yeast P. kluyveri indicates that the mode of inheritance of killer toxin production is nuclear and not cytoplasmic as is found in Saccharomyces cerevisiae and Kluyveromyces lactis.

Genes encoding DNA polymerases on linear dsDNA plasmids of Debaryomyces hansenii yeasts share very high homology

2014 ◽  
Vol 31 ◽  
pp. S219
Author(s):  
Xymena Połomska ◽  
Cecile Neuveglise ◽  
Zbigniew Lazar ◽  
Barbara Zarowska
Keyword(s):  
Dna Polymerases ◽  
Debaryomyces Hansenii ◽  
High Homology ◽  
Genes Encoding ◽  
Linear Dsdna ◽  
Very High

scholarly journals Transcriptional Regulation of Genes Encoding the Selenium-Free [NiFe]-Hydrogenases in the Archaeon Methanococcus voltae Involves Positive and Negative Control Elements

Genetics ◽  
1999 ◽  
Vol 152 (4) ◽  
pp. 1335-1341
Author(s):  
Izabela Noll ◽  
Steffen Müller ◽  
Albrecht Klein
Keyword(s):  
Intergenic Region ◽  
Genetic Information ◽  
Regulatory Element ◽  
Transcription Unit ◽  
Negative Control ◽  
Negative Regulation ◽  
Negative Regulatory Element ◽  
Methanococcus Voltae ◽  
Genes Encoding ◽  
Made In

Abstract Methanococcus voltae harbors genetic information for two pairs of homologous [NiFe]-hydrogenases. Two of the enzymes contain selenocysteine, while the other two gene groups encode apparent isoenzymes that carry cysteinyl residues in the homologous positions. The genes coding for the selenium-free enzymes, frc and vhc, are expressed only under selenium limitation. They are transcribed out of a common intergenic region. A series of deletions made in the intergenic region localized a common negative regulatory element for the vhc and frc promoters as well as two activator elements that are specific for each of the two transcription units. Repeated sequences, partially overlapping the frc promoter, were also detected. Mutations in these repeated heptanucleotide sequences led to a weak induction of a reporter gene under the control of the frc promoters in the presence of selenium. This result suggests that the heptamer repeats contribute to the negative regulation of the frc transcription unit.

Selection of preservation conditions for Debaryomyces hansenii yeasts killer toxins

2014 ◽  
Vol 31 ◽  
pp. S218
Author(s):  
Barbara Zarowska ◽  
Lukasz Bobak ◽  
Piotr Regiec ◽  
Adam Figiel ◽  
Monika Grzegorczyk ◽  
...  
Keyword(s):  
Debaryomyces Hansenii ◽  
Killer Toxins ◽  
Preservation Conditions ◽  
Selection Of

scholarly journals Divergence of Peroxisome Membrane Gene Sequence and Expression Between Yeast Species

2020 ◽  
Vol 10 (6) ◽  
pp. 2079-2085
Author(s):  
Claire A. Dubin ◽  
Jeremy I. Roop ◽  
Rachel B. Brem
Keyword(s):  
Molecular Mechanisms ◽  
Genomic Sequence ◽  
Yeast Species ◽  
Large Population ◽  
Adaptive Divergence ◽  
Comparative Genomic ◽  
Sequencing Studies ◽  
Genes Encoding ◽  
Mechanisms Of Adaptation ◽  
Peroxisome Membrane

Large population-genomic sequencing studies can enable highly-powered analyses of sequence signatures of natural selection. Genome repositories now available for Saccharomyces yeast make it a premier model for studies of the molecular mechanisms of adaptation. We mined the genomes of hundreds of isolates of the sister species S. cerevisiae and S. paradoxus to identify sequence hallmarks of adaptive divergence between the two. From the top hits we focused on a set of genes encoding membrane proteins of the peroxisome, an organelle devoted to lipid breakdown and other specialized metabolic pathways. In-depth population- and comparative-genomic sequence analyses of these genes revealed striking divergence between S. cerevisiae and S. paradoxus. And from transcriptional profiles we detected non-neutral, directional cis-regulatory variation at the peroxisome membrane genes, with overall high expression in S. cerevisiae relative to S. paradoxus. Taken together, these data support a model in which yeast species have differentially tuned the expression of peroxisome components to boost their fitness in distinct niches.

Biodiversity of killer activity in yeasts isolated from the Brazilian rain forest

2000 ◽  
Vol 46 (7) ◽  
pp. 607-611 ◽  
Author(s):  
Pietro Buzzini ◽  
Alessandro Martini
Keyword(s):  
Rain Forest ◽  
Debaryomyces Hansenii ◽  
Cryptococcus Laurentii ◽  
Plasmid Curing ◽  
Candida Maltosa ◽  
Killer Activity ◽  
Pseudozyma Antarctica ◽  
Tropical Environments ◽  
Toxin Producers

The occurrence of killer activity against a panel composed of 22 industrially and (or) medically important yeasts was investigated in 438 yeast and yeast-like cultures belonging to 96 species, isolated from different environments of the Brazilian rain forest. Altogether, 26% of ascomycetes, 56% of basidiomycetes, and 42% of yeast-like cultures exhibited killer activity against at least one of the panel yeasts. More than 15 species never reported before as toxin producers were found, with Pseudozyma antarctica, Trichosporon asteroides, and Geotrichum klebahnii, showing the broader activity spectra. Plasmid curing did not cure the killer phenotypes of Candida maltosa, Debaryomyces hansenii, G. klebahnii, Tr. asteroides, Cryptococcus laurentii, and Ps. antarctica.Key words: yeasts, killer activity, tropical environments.

Factors affecting killer activity of some yeast species occurring in rokpol cheese

2004 ◽  
Vol 49 (6) ◽  
pp. 713-717 ◽  
Author(s):  
B. Żarowska ◽  
M. Wojtatowicz ◽  
X. Polomska ◽  
P. Juszczyk ◽  
J. Chrzanowska
Keyword(s):  
Yeast Species ◽  
Killer Activity ◽  
Factors Affecting

scholarly journals The Species-Specific Acquisition and Diversification of a K1-like Family of Killer Toxins in Budding Yeasts of the Saccharomycotina

PLoS Genetics ◽  
2021 ◽  
Vol 17 (2) ◽  
pp. e1009341 ◽  
Author(s):  
Lance R. Fredericks ◽  
Mark D. Lee ◽  
Angela M. Crabtree ◽  
Josephine M. Boyer ◽  
Emily A. Kizer ◽  
...  
Keyword(s):  
Yeast Species ◽  
Killer Toxin ◽  
Biologically Active ◽  
Genetic Sequencing ◽  
Evolutionary Origins ◽  
Killer Toxins ◽  
Antifungal Proteins ◽  
Dsrna Viruses ◽  
Niche Competition ◽  
Species Specific

Killer toxins are extracellular antifungal proteins that are produced by a wide variety of fungi, including Saccharomyces yeasts. Although many Saccharomyces killer toxins have been previously identified, their evolutionary origins remain uncertain given that many of these genes have been mobilized by double-stranded RNA (dsRNA) viruses. A survey of yeasts from the Saccharomyces genus has identified a novel killer toxin with a unique spectrum of activity produced by Saccharomyces paradoxus. The expression of this killer toxin is associated with the presence of a dsRNA totivirus and a satellite dsRNA. Genetic sequencing of the satellite dsRNA confirmed that it encodes a killer toxin with homology to the canonical ionophoric K1 toxin from Saccharomyces cerevisiae and has been named K1-like (K1L). Genomic homologs of K1L were identified in six non-Saccharomyces yeast species of the Saccharomycotina subphylum, predominantly in subtelomeric regions of the genome. When ectopically expressed in S. cerevisiae from cloned cDNAs, both K1L and its homologs can inhibit the growth of competing yeast species, confirming the discovery of a family of biologically active K1-like killer toxins. The sporadic distribution of these genes supports their acquisition by horizontal gene transfer followed by diversification. The phylogenetic relationship between K1L and its genomic homologs suggests a common ancestry and gene flow via dsRNAs and DNAs across taxonomic divisions. This appears to enable the acquisition of a diverse arsenal of killer toxins by different yeast species for potential use in niche competition.

scholarly journals Several Yeast Species Induce Iron Deficiency Responses in Cucumber Plants (Cucumis sativus L.)

2021 ◽  
Vol 9 (12) ◽  
pp. 2603
Author(s):  
Carlos Lucena ◽  
María T. Alcalá-Jiménez ◽  
Francisco J. Romera ◽  
José Ramos
Keyword(s):  
Yeast Species ◽  
Reductase Activity ◽  
Hansenula Polymorpha ◽  
Debaryomyces Hansenii ◽  
Root Hairs ◽  
Fe Deficiency ◽  
Ferric Reductase ◽  
Cucumis Sativus L ◽  
Growth System ◽  
Promising Line

Iron (Fe) deficiency is a first-order agronomic problem that causes a significant decrease in crop yield and quality. Paradoxically, Fe is very abundant in most soils, mainly in its oxidized form, but is poorly soluble and with low availability for plants. In order to alleviate this situation, plants develop different morphological and physiological Fe-deficiency responses, mainly in their roots, to facilitate Fe mobilization and acquisition. Even so, Fe fertilizers, mainly Fe chelates, are widely used in modern agriculture, causing environmental problems and increasing the costs of production, due to the high prices of these products. One of the most sustainable and promising alternatives to the use of agrochemicals is the better management of the rhizosphere and the beneficial microbial communities presented there. The main objective of this research has been to evaluate the ability of several yeast species, such as Debaryomyces hansenii, Saccharomyces cerevisiae and Hansenula polymorpha, to induce Fe-deficiency responses in cucumber plants. To date, there are no studies on the roles played by yeasts on the Fe nutrition of plants. Experiments were carried out with cucumber plants grown in a hydroponic growth system. The effects of the three yeast species on some of the most important Fe-deficiency responses developed by dicot (Strategy I) plants, such as enhanced ferric reductase activity and Fe2+ transport, acidification of the rhizosphere, and proliferation of subapical root hairs, were evaluated. The results obtained show the inductive character of the three yeast species, mainly of Debaryomyces hansenii and Hansenula polymorpha, on the Fe-deficiency responses evaluated in this study. This opens a promising line of study on the use of these microorganisms as Fe biofertilizers in a more sustainable and environmentally friendly agriculture.

Elevated minimum inhibitory concentrations to antifungal drugs prevail in 14 rare species of candidemia-causing Saccharomycotina yeasts

2020 ◽  
Vol 58 (7) ◽  
pp. 987-995
Author(s):  
Aimilia A Stavrou ◽  
Antonio Pérez-Hansen ◽  
Michaela Lackner ◽  
Cornelia Lass-Flörl ◽  
Teun Boekhout
Keyword(s):  
Rare Species ◽  
Yeast Species ◽  
Antifungal Susceptibility ◽  
Debaryomyces Hansenii ◽  
Antifungal Drugs ◽  
Antifungal Compound ◽  
Candida Auris ◽  
Minimum Inhibitory Concentrations ◽  
Rare Yeast Species ◽  
Multiple Drugs

Abstract Antifungal susceptibility profiles of rare Saccharomycotina yeasts remain missing, even though an increase in prevalence of such rare Candida species was reported in candidemia. Majority of these rare yeast species carry intrinsic resistances against at least one antifungal compound. Some species are known to be cross-resistant (against multiple drugs of the same drug class) or even multi-drug resistant (against multiple drugs of different drug classes). We performed antifungal susceptibility testing (AFST) according to EUCAST broth microdilution for 14 rare species (Clavispora lusitaniae, Candida intermedia, Candida auris, Diutina rugosa, Wickerhamiella pararugosa, Yarrowia lipolytica, Pichia norvegensis, Candida nivariensis, Kluyveromyces marxianus, Wickerhamomyces anomalus, Candida palmioleophila, Meyerozyma guilliermondii, Meyerozyma caribbica, and Debaryomyces hansenii) known to cause candidemia. In total, 234 isolates were tested for amphotericin B, fluconazole, itraconazole, voriconazole, posaconazole, anidulafungin, micafungin, and caspofungin. Amphothericin B had the broadest efficiency against the 14 tested rare yeast species, while high minimum inhibitory concentrations (MICs) against azole drugs and echinocandins were common. Voriconazole was the most efficient azole drug. Multidrug resistance was observed for the species C. auris and K. marxianus. Multidrug resistant individual isolates were found for Y. lipolytica and M. caribbica. In conclusion, the observed high MIC values of the rare Saccharomycotina species tested limit antifungal treatment options, complicating the management of such infections.

Sign in / Sign up

Export Citation Format

Share Document