scholarly journals Structures of cell wall mannans of pathogenic Candida tropicalis IFO 0199 and IFO 1647 yeast strains.

1994 ◽  
Vol 62 (2) ◽  
pp. 615-622 ◽  
Author(s):  
H Kobayashi ◽  
K Matsuda ◽  
T Ikeda ◽  
M Suzuki ◽  
S Takahashi ◽  
...  
Keyword(s):  
Cell Wall ◽  
Candida Tropicalis ◽  
Yeast Strains

Distribution of antigenic oligomannosyl side chains in the cell wall mannans of several strains of Candida tropicalis

2003 ◽  
Vol 180 (1) ◽  
pp. 76-80 ◽  
Author(s):  
Hidemitsu Kobayashi ◽  
Hiroko Oyamada ◽  
Kyoko Matsuda ◽  
Nobuyuki Shibata ◽  
Shigeo Suzuki
Keyword(s):  
Cell Wall ◽  
Candida Tropicalis ◽  
Side Chains

scholarly journals Cell Wall Changes in Amphotericin B-Resistant Strains from Candida tropicalis and Relationship with the Immune Responses Elicited by the Host

2016 ◽  
Vol 60 (4) ◽  
pp. 2326-2335 ◽  
Author(s):  
Ana C. Mesa-Arango ◽  
Cristina Rueda ◽  
Elvira Román ◽  
Jessica Quintin ◽  
María C. Terrón ◽  
...  
Keyword(s):  
Immune Response ◽  
Cell Wall ◽  
Amphotericin B ◽  
Candida Tropicalis ◽  
Galleria Mellonella ◽  
Regular Growth ◽  
Cell Integrity ◽  
Proinflammatory Response ◽  
Content Type ◽  
Resistant Strains

ABSTRACTWe have morphologically characterizedCandida tropicalisisolates resistant to amphotericin B (AmB). These isolates present an enlarged cell wall compared to isolates of regular susceptibility. This correlated with higher levels of β-1,3-glucan in the cell wall but not with detectable changes in chitin content. In line with this, AmB-resistant strains showed reduced susceptibility to Congo red. Moreover, mitogen-activated protein kinases (MAPKs) involved in cell integrity were already activated during regular growth in these strains. Finally, we investigated the response elicited by human blood cells and found that AmB-resistant strains induced a stronger proinflammatory response than susceptible strains. In agreement, AmB-resistant strains also induced stronger melanization ofGalleria mellonellalarvae, indicating that the effect of alterations of the cell wall on the immune response is conserved in different types of hosts. Our results suggest that resistance to AmB is associated with pleiotropic mechanisms that might have important consequences, not only for the efficacy of the treatment but also for the immune response elicited by the host.

scholarly journals Vacuolar H+-ATPase Protects Saccharomyces cerevisiae Cells against Ethanol-Induced Oxidative and Cell Wall Stresses

2016 ◽  
Vol 82 (10) ◽  
pp. 3121-3130 ◽  
Author(s):  
Sirikarn Charoenbhakdi ◽  
Thanittra Dokpikul ◽  
Thanawat Burphan ◽  
Todsapol Techo ◽  
Choowong Auesukaree
Keyword(s):  
Cell Wall ◽  
Alcoholic Fermentation ◽  
Ethanol Tolerance ◽  
Wall Stress ◽  
Yeast Cells ◽  
Intracellular Acidification ◽  
Straight Chain ◽  
Cell Wall Stress ◽  
Yeast Strains ◽  
Vacuolar Acidification

ABSTRACTDuring fermentation, increased ethanol concentration is a major stress for yeast cells. Vacuolar H+-ATPase (V-ATPase), which plays an important role in the maintenance of intracellular pH homeostasis through vacuolar acidification, has been shown to be required for tolerance to straight-chain alcohols, including ethanol. Since ethanol is known to increase membrane permeability to protons, which then promotes intracellular acidification, it is possible that the V-ATPase is required for recovery from alcohol-induced intracellular acidification. In this study, we show that the effects of straight-chain alcohols on membrane permeabilization and acidification of the cytosol and vacuole are strongly dependent on their lipophilicity. These findings suggest that the membrane-permeabilizing effect of straight-chain alcohols induces cytosolic and vacuolar acidification in a lipophilicity-dependent manner. Surprisingly, after ethanol challenge, the cytosolic pH in Δvma2and Δvma3mutants lacking V-ATPase activity was similar to that of the wild-type strain. It is therefore unlikely that the ethanol-sensitive phenotype ofvmamutants resulted from severe cytosolic acidification. Interestingly, thevmamutants exposed to ethanol exhibited a delay in cell wall remodeling and a significant increase in intracellular reactive oxygen species (ROS). These findings suggest a role for V-ATPase in the regulation of the cell wall stress response and the prevention of endogenous oxidative stress in response to ethanol.IMPORTANCEThe yeastSaccharomyces cerevisiaehas been widely used in the alcoholic fermentation industry. Among the environmental stresses that yeast cells encounter during the process of alcoholic fermentation, ethanol is a major stress factor that inhibits yeast growth and viability, eventually leading to fermentation arrest. This study provides evidence for the molecular mechanisms of ethanol tolerance, which is a desirable characteristic for yeast strains used in alcoholic fermentation. The results revealed that straight-chain alcohols induced cytosolic and vacuolar acidification through their membrane-permeabilizing effects. Contrary to expectations, a role for V-ATPase in the regulation of the cell wall stress response and the prevention of endogenous oxidative stress, but not in the maintenance of intracellular pH, seems to be important for protecting yeast cells against ethanol stress. These findings will expand our understanding of the mechanisms of ethanol tolerance and provide promising clues for the development of ethanol-tolerant yeast strains.

Detection of Zygosaccharomyces rouxii and Candida tropicalis in a High-Sugar Medium by a Metal Oxide Sensor–Based Electronic Nose and Comparison with Test Panel Evaluation

2015 ◽  
Vol 78 (11) ◽  
pp. 2052-2063 ◽  
Author(s):  
HUXUAN WANG ◽  
ZHONGQIU HU ◽  
FANGYU LONG ◽  
CHUNFENG GUO ◽  
YAHONG YUAN ◽  
...  
Keyword(s):  
Electronic Nose ◽  
Candida Tropicalis ◽  
Solid Phase ◽  
Reference Method ◽  
Test Panel ◽  
Zygosaccharomyces Rouxii ◽  
High Sugar ◽  
Yeast Strains ◽  
Total Yeast ◽  
Panel Evaluation

Osmotolerant yeasts are primarily responsible for spoilage of sugar-rich foods. In this work, an electronic nose (e-nose) was used to diagnose contamination caused by two osmotolerant yeast strains (Zygosaccharomyces rouxii and Candida tropicalis) in a high-sugar medium using test panel evaluation as the reference method. Solid-phase microextraction gas chromatography with mass spectrometry (GC-MS) was used to determine the evolution of the volatile organic compound fingerprint in the contaminated samples during yeast growth. Principal component analysis and linear discriminant analysis revealed that the e-nose could identify contamination after 48 h, corresponding to the total yeast levels of 3.68 (Z. rouxii) and 3.09 (C. tropicalis) log CFU/ml. At these levels, the test panel could not yet diagnose the spoilage, indicating that the e-nose approach was more sensitive than the test panel evaluation. Loading analysis indicated that sensors 8 and 6 were the most important for detection of these two yeasts. Based on the result obtained with the e-nose, the incubation time and total yeast levels could be accurately predicted by established multiple regression models with a correlation of greater than 0.97. In the sensory evaluation, spoilage was diagnosed after 72 h in samples contaminated with C. tropicalis and after 48 to 72 h for samples contaminated with Z. rouxii. GC-MS revealed that compounds such as acetaldehyde, acetone, ethyl acetate, alcohol, and 3-methyl-1-butanol contributed to spoilage detection by the e-nose after 48 h. In the high-sugar medium, the e-nose was more sensitive than the test panel evaluation for detecting contamination with these test yeast strains. This information could be useful for developing instruments and techniques for rapid scanning of sugar-rich foods for contamination with osmotolerant yeasts before such spoilage could be detected by the consumer.

scholarly journals Cell Wall and Whole Cell Proteomes Define Flocculation and Fermentation Behavior of Yeast

Fermentation ◽  
2018 ◽  
Vol 4 (3) ◽  
pp. 80 ◽  
Author(s):  
Edward Kerr ◽  
Duin McDiarmid ◽  
James Fraser ◽  
Benjamin Schulz
Keyword(s):  
Cell Wall ◽  
Protein Abundance ◽  
Metabolic Diversity ◽  
Brewing Yeast ◽  
Whole Cell ◽  
Flocculation Efficiency ◽  
Yeast Strains ◽  
Commercial Yeast ◽  
The Relationship

Flocculation is one of the most important characteristics of brewing yeast as it allows for the easy and cheap removal of cells after fermentation. The genes responsible for both the Flo1 and NewFlo flocculation phenotypes are well characterized. However, the relationship between Flo protein abundance and flocculation efficiency is poorly understood. In this present study, we used mass spectrometry proteomics to compare the cell wall and whole cell proteomes of commercial yeast strains with diverse flocculation behaviors. We found that the relative abundance of Flo1/5 or Flo10 in the cell wall was correlated with the ability of these yeast strains to flocculate. Analysis of whole cell proteomes identified differences in the proteomes of yeast strains and identified the potential for high metabolic diversity. Characterization of the cell wall and whole cell proteomes during fermentation showed high levels of Flo10 in cells that settled early during fermentation. Our data reveal the diversity of the cell wall and global proteomes of brewing yeast, highlighting the potential biochemical diversity present in yeast that can be utilized in the production of fermented beverages.

scholarly journals Yeast Cell Wall Chitin Reduces Wine Haze Formation

2018 ◽  
Vol 84 (13) ◽  
Author(s):  
Thulile Ndlovu ◽  
Benoit Divol ◽  
Florian F. Bauer
Keyword(s):  
Cell Wall ◽  
Yeast Cell ◽  
Wine Yeast ◽  
Wine Industry ◽  
Yeast Cell Wall ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Yeast Strains ◽  
Protein Haze ◽  
Haze Formation

ABSTRACT Protein haze formation in bottled wines is a significant concern for the global wine industry, and wine clarification before bottling is therefore a common but expensive practice. Previous studies have shown that wine yeast strains can reduce haze formation through the secretion of certain mannoproteins, but it has been suggested that other yeast-dependent haze protective mechanisms exist. On the other hand, the addition of chitin has been shown to reduce haze formation, likely because grape chitinases have been shown to be the major contributors to haze. In this study, Chardonnay grape must fermented by various yeast strains resulted in wines with different protein haze levels, indicating differences in haze-protective capacities of the strains. The cell wall chitin levels of these strains were determined, and a strong correlation between cell wall chitin levels and haze protection capability was observed. To further evaluate the mechanism of haze protection, Escherichia coli -produced green fluorescent protein (GFP)-tagged grape chitinase was shown to bind efficiently to yeast cell walls in a cell wall chitin concentration-dependent manner, while commercial chitinase was removed from synthetic wine in quantities that also correlated with the cell wall chitin levels of the strains. Our findings suggest a new mechanism of reducing wine haze, and we propose a strategy for optimizing wine yeast strains to improve wine clarification. IMPORTANCE In this study, we establish a new mechanism by which wine yeast strains can impact the protein haze formation of wines, and we demonstrate that yeast cell wall chitin binds grape chitinase in a chitin concentration-dependent manner. We also show that yeast can remove this haze-forming protein from wine. Chitin has in the past been shown to efficiently reduce wine haze formation when added to the wine in high concentration as a clarifying agent. Our data suggest that the selection of yeast strains with high levels of cell wall chitin can reduce protein haze. We also investigate how yeast cell wall chitin levels are affected by environmental conditions.

Binding and activation of the human plasma kinin-forming system on the cell walls of Candida albicans and Candida tropicalis

2010 ◽  
Vol 391 (1) ◽  
Author(s):  
Justyna Karkowska-Kuleta ◽  
Andrzej Kozik ◽  
Maria Rapala-Kozik
Keyword(s):  
Cell Wall ◽  
Candida Albicans ◽  
Candida Tropicalis ◽  
Cell Walls ◽  
Bacterial Infections ◽  
Coagulation Factor ◽  
Contact System ◽  
Factor Xii ◽  
Cell Surfaces ◽  
Plasma Kinin

Abstract Bacterial infections often upregulate the plasma kinin-forming cascade of the host (the ‘contact system’) which is triggered by adsorption of high molecular mass kininogen (HK), coagulation factor XII (FXII) and prekallikrein (pHPK) on the host or pathogen cell surfaces. A possible activation of the contact system upon infection of the human host by major fungal pathogens of Candida species has not been extensively explored until a recent report of tight binding of HK to the cell walls of these fungi. In the current study, the adsorption of the other contact system components to the cell surfaces of Candida albicans and Candida tropicalis was characterized. FXII was found to be tightly bound by Candida germ tube forms, to a level 5-fold higher than that for HK. In contrast, pHPK bound poorly but its additional amounts could dock to the cell wall through the surface-bound HK. It was also shown that within the complex of these proteins assembled on the cell walls of fungal hyphae, pHPK could be activated by FXIIa and the active HPK effectively produced kinins from HK. It is suggested that kinins, released at the Candida cell wall, can promote host colonization by the pathogen and the development of infection.

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