Assessment of the atmospheric fungal prevalence through field ergosterol measurement I—Determination of the specific ergosterol content in common ambient fungal spores and yeast cells

2008 ◽  
Vol 42 (22) ◽  
pp. 5526-5533 ◽  
Author(s):  
Jessica Y.W. Cheng ◽  
Arhur P.S. Lau ◽  
Ming Fang
Keyword(s):  
Fungal Spores ◽  
Yeast Cells ◽  
Ergosterol Content

scholarly journals The CDC42 Homolog of the Dimorphic FungusPenicillium marneffei Is Required for Correct Cell Polarization during Growth but Not Development

2001 ◽  
Vol 183 (11) ◽  
pp. 3447-3457 ◽  
Author(s):  
Kylie J. Boyce ◽  
Michael J. Hynes ◽  
Alex Andrianopoulos
Keyword(s):  
Cell Shape ◽  
Pathogenic Fungus ◽  
Cell Polarization ◽  
Dominant Negative ◽  
Yeast Cells ◽  
Polarized Growth ◽  
Temperature Dependent ◽  
Human Pathogenic Fungus ◽  
Rho Family

ABSTRACT The opportunistic human pathogenic fungus Penicillium marneffei is dimorphic and is thereby capable of growth either as filamentous multinucleate hyphae or as uninucleate yeast cells which divide by fission. The dimorphic switch is temperature dependent and requires regulated changes in morphology and cell shape. Cdc42p is a Rho family GTPase which in Saccharomyces cerevisiae is required for changes in polarized growth during mating and pseudohyphal development. Cdc42p homologs in higher organisms are also associated with changes in cell shape and polarity. We have cloned a highly conserved CDC42 homolog from P. marneffeinamed cflA. By the generation of dominant-negative and dominant-activated cflA transformants, we have shown that CflA initiates polarized growth and extension of the germ tube and subsequently maintains polarized growth in the vegetative mycelium. CflA is also required for polarization and determination of correct cell shape during yeast-like growth, and active CflA is required for the separation of yeast cells. However, correct cflAfunction is not required for dimorphic switching and does not appear to play a role during the generation of specialized structures during asexual development. In contrast, heterologous expression ofcflA alleles in Aspergillus nidulansprevented conidiation.

scholarly journals Quantifying Mold Biomass on Gypsum Board: Comparison of Ergosterol and Beta-N-Acetylhexosaminidase as Mold Biomass Parameters

2003 ◽  
Vol 69 (7) ◽  
pp. 3996-3998 ◽  
Author(s):  
M. Reeslev ◽  
M. Miller ◽  
K. F. Nielsen
Keyword(s):  
Stationary Phase ◽  
Linear Correlation ◽  
Stachybotrys Chartarum ◽  
Gypsum Board ◽  
Biomass Density ◽  
Activity Data ◽  
Good Linear ◽  
Ergosterol Content ◽  
Good Linear Correlation

ABSTRACT Two mold species, Stachybotrys chartarum and Aspergillus versicolor, were inoculated onto agar overlaid with cellophane, allowing determination of a direct measurement of biomass density by weighing. Biomass density, ergosterol content, and beta-N-acetylhexosaminidase (3.2.1.52) activity were monitored from inoculation to stationary phase. Regression analysis showed a good linear correlation to biomass density for both ergosterol content and beta-N-acetylhexosaminidase activity. The same two mold species were inoculated onto wallpapered gypsum board, from which a direct biomass measurement was not possible. Growth was measured as an increase in ergosterol content and beta-N-acetylhexosaminidase activity. A good linear correlation was seen between ergosterol content and beta-N-acetylhexosaminidase activity. From the experiments performed on agar medium, conversion factors (CFs) for estimating biomass density from ergosterol content and beta-N-acetylhexosaminidase activity were determined. The CFs were used to estimate the biomass density of the molds grown on gypsum board. The biomass densities estimated from ergosterol content and beta-N-acetylhexosaminidase activity data gave similar results, showing significantly slower growth and lower stationary-phase biomass density on gypsum board than on agar.

scholarly journals ESR as a monitoring method of the interactions between TEMPO-functionalized magnetic nanoparticles and yeast cells

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Ryszard Krzyminiewski ◽  
Bernadeta Dobosz ◽  
Grzegorz Schroeder ◽  
Joanna Kurczewska
Keyword(s):  
Magnetic Nanoparticles ◽  
Drug Carriers ◽  
Magnetic Core ◽  
Yeast Cells ◽  
Spin Labels ◽  
Monitoring Method ◽  
Functionalized Magnetic Nanoparticles ◽  
Spin Resonance

AbstractPotential application of magnetic nanoparticles as drug carriers in medical treatment requires prior determination of their effects on cells. In this work different spin labels and magnetic nanoparticles functionalized with spin labels as well as their interaction with yeast cells were investigated using electron spin resonance (ESR) method. ESR was demonstrated to be a suitable method for monitoring of magnetic core and attached spin labels. Particular emphasis was placed on characterization of endocytosis and redox processes running inside the cell, resulting in recombination of spin labels. Such data could only be obtained at reduced temperature of ESR measurements.

scholarly journals Characterization and Structural Determination of Cold-Adapted Monodehydroascorbate Reductase, MDHAR, from the Antarctic Hairgrass Deschampsia Antarctica

Crystals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 537 ◽  
Author(s):  
Ae Kyung Park ◽  
Il-Sup Kim ◽  
Hackwon Do ◽  
Hyun Kim ◽  
Woong Choi ◽  
...  
Keyword(s):  
Oryza Sativa L ◽  
Extreme Temperature ◽  
Biochemical Properties ◽  
Yeast Cells ◽  
Monodehydroascorbate Reductase ◽  
Deschampsia Antarctica ◽  
Freezing And Thawing ◽  
Freezing And Thawing Cycles ◽  
The Antarctic

Ascorbic acid (AsA) is an abundant component of plants and acts as a strong and active antioxidant. In order to maintain the antioxidative capacity of AsA, the rapid regeneration of AsA is regulated by dehydroascorbate reductase (DHAR) and monodehydroascorbate reductase (MDHAR). To understand how MDHAR functions under extreme temperature conditions, this study characterized its biochemical properties and determined the crystal structure of MDHAR from the Antarctic hairgrass Deschampsia antarctica (DaMDHAR) at 2.2 Å resolution. This allowed for a structural comparison with the mesophilic MDHAR from Oryza sativa L. japonica (OsMDHAR). In the functional analysis, yeast cells expressing DaMDHAR were tolerant to freezing and thawing cycles. It is possible that the expression of DaMDHAR in yeast enhanced the tolerance for ROS-induced abiotic stress.

Use of permeabilized yeast cells for the determination of ethanol and alcohol dehydrogenase assay

1982 ◽  
Vol 123 (1) ◽  
pp. 205-207 ◽  
Author(s):  
Carlos Pascual ◽  
Roberto Pascual ◽  
Arnošt Kotyk
Keyword(s):  
Alcohol Dehydrogenase ◽  
Yeast Cells

scholarly journals Rhodotorula glutinis: STRAIN ENRICHMENT AND EVALUATION OF PHENYLALANINE AMMONIA LYASE

2007 ◽  
Vol 44 (1) ◽  
Author(s):  
M. Jason MacDonald ◽  
Godwin B. D'Cunha
Keyword(s):  
Nous Avons ◽  
Yeast Extract ◽  
Phenylalanine Ammonia Lyase ◽  
Rhodotorula Glutinis ◽  
Yeast Cells ◽  
Pal Activity ◽  
Yeast Extract Medium ◽  
Extract Medium ◽  
Phenylalanine Methyl Ester

2006 NSIS Honourable Mention, Undergraduate Student ResearchPrize Winning PaperThe enrichment of a Rhodotorula glufinis strain and the determination of itsphenylalanine ammonia lyase (E.C.4.3.1.5 - PAL) activity and attempts to measure peroxidase (E.C.1.11.1. 7) activity included conventional mycological procedures along with chemical and microscopic examination. Sabouraud dextrose medium was found to be the most suitable for cell growth, but cells grown on yeast-extract medium exhibited optimal enzyme activity. Growth and PAL activity were measured in yeast cells grown in yeast-extract broth medium for 24-27 h. The appearance of a reddish pink color associated with the yeast cells coincided with the appearance of appreciable PAL activity. The maximum PAL activity and biomass of yeast obtained in the yeast extract medium ranged from 33 to 35 unitslmg dry cells and 7.5 to 8.0 g dry cells/l, respectively. In addition to phenylalanine, Rhodatowla PAL also used phenylalanine methyl-ester as a substrate. No peroxidase activity was found in these R. glutinis cells.L'enrichissement de la souche de Rhodatarula glutinis et la detenmination de l'activite de la phenylalanine ammoniac-lyase (E.C.4.3.1.5 - PAL) chez cette souche, de meme que les tentatives de mesure de I'activite de la peroxydase (E.C.1 .11.1 .7), ont compris I'utilisation de procedures mycologiques traditionnelles ainsi que des examens microscopiques et chimiques. Nous avons constate que la gelose Sabouraud au dextrose est Ie meilleur milieu pour assurer la croissance cellulaire, mais que l'activite enzymatique est optimale dans les cellules cultivees sur un milieu a base d'extrait de levure. Nousavons mesure la croissance de cellulesde levure culliveesdans un bouillon a base d'extrait de levure pendant 24 a 27 heures et nous avons mesure I'activite de la PAL dans ces memes cellules. L'apparition d'une couleur rose rougeatre associee aux cellules de levure a coIncide avec Ie debut d'une periode d'activite notable de laPAL. L'activite maxima Ie de la PAL obtenue dans Ie milieu a base d'exlrait de levure a varie de 33 a 35 unites par mg de cellules seches, tandis que la biomasse de levure maximale obtenue dans Ie meme milieu a varie de 7,5 a 8,0 9 de cellules seches par litre. En plus de la phenylalanine, la PAlde Rhodotorula a utilise I'ester methylique de la phenylalanine comme substrat. Aucune activite de la peroxydase n'a ete observee dans ces cellules de R. glutinis.•

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