YNB (10×) (13.4% Yeast Nitrogen Base with Ammonium Sulfate, without Amino Acids)

2021 ◽  
Vol 2021 (1) ◽  
pp. pdb.rec105239
Keyword(s):  
Amino Acids ◽  
Ammonium Sulfate ◽  
Yeast Nitrogen Base ◽  
Nitrogen Base

scholarly journals Improved Properties of Baker's Yeast Mutants Resistant to 2-Deoxy-d-Glucose

2001 ◽  
Vol 67 (9) ◽  
pp. 4279-4285 ◽  
Author(s):  
Ana M. Rincón ◽  
Antonio C. Codón ◽  
Francisco Castrejón ◽  
Tahı́a Benı́tez
Keyword(s):  
Ammonium Sulfate ◽  
Baker’S Yeast ◽  
Yeast Nitrogen Base ◽  
Baker's Yeast ◽  
Wild Type ◽  
Organoleptic Properties ◽  
Nitrogen Base ◽  
Fermentative Capacity ◽  
Yeast Mutants ◽  
Spontaneous Mutants

ABSTRACT We isolated spontaneous mutants from Saccharomyces cerevisiae (baker's yeast V1) that were resistant to 2-deoxy-d-glucose and had improved fermentative capacity on sweet doughs. Three mutants could grow at the same rate as the wild type in minimal SD medium (0.17% Difco yeast nitrogen base without amino acids and ammonium sulfate, 0.5% ammonium sulfate, 2% glucose) and had stable elevated levels of maltase and/or invertase under repression conditions but lower levels in maltose-supplemented media. Two of the mutants also had high levels of phosphatase active on 2-deoxy-d-glucose-6-phosphate. Dough fermentation (CO2 liberation) by two of the mutants was faster and/or produced higher final volumes than that by the wild type, both under laboratory and industrial conditions, when the doughs were supplemented with glucose or sucrose. However, the three mutants were slower when fermenting plain doughs. Fermented sweet bakery products obtained with these mutants were of better quality than those produced by the wild type, with regard to their texture and their organoleptic properties.

scholarly journals Process Analysis of Variables for Standardization of Antifungal Susceptibility Testing of Nonfermentative Yeasts

2011 ◽  
Vol 55 (4) ◽  
pp. 1563-1570 ◽  
Author(s):  
Oscar Zaragoza ◽  
Ana C. Mesa-Arango ◽  
Alicia Gómez-López ◽  
Leticia Bernal-Martínez ◽  
Juan Luis Rodríguez-Tudela ◽  
...  
Keyword(s):  
Ammonium Sulfate ◽  
Growth Kinetics ◽  
Susceptibility Testing ◽  
Process Analysis ◽  
Antifungal Susceptibility ◽  
Inoculum Size ◽  
Antifungal Susceptibility Testing ◽  
Yeast Nitrogen Base ◽  
Nitrogen Base ◽  
Static Conditions

ABSTRACTNonfermentative yeasts, such asCryptococcusspp., have emerged as fungal pathogens during the last few years. However, standard methods to measure their antifungal susceptibility (antifungal susceptibility testing [AST]) are not completely reliable due to the impaired growth of these yeasts in standard media. In this work, we have compared the growth kinetics and the antifungal susceptibilities of representative species of nonfermentative yeasts such asCryptococcus neoformans,Cryptococcus gattii,Cryptococcus albidus,Rhodotorulaspp.,Yarrowia lipolytica,Geotrichumspp., andTrichosporonspp. The effect of the growth medium (RPMI medium versus yeast nitrogen base [YNB]), glucose concentration (0.2% versus 2%), nitrogen source (ammonium sulfate), temperature (30°C versus 35°C), shaking, and inoculum size (103, 104, and 105cells) were analyzed. The growth rate, lag phase, and maximum optical density were obtained from each growth experiment, and after multivariate analysis, YNB-based media demonstrated a significant improvement in the growth of yeasts. Shaking, an inoculum size of 105CFU/ml, and incubation at 30°C also improved the growth kinetics of organisms. Supplementation with ammonium sulfate and with 2% glucose did not have any effect on growth. We also tested the antifungal susceptibilities of all the isolates by the reference methods of the CLSI and EUCAST, the EUCAST method with shaking, YNB under static conditions, and YNB with shaking. MIC values obtained under different conditions showed high percentages of agreement and significant correlation coefficient values between them. MIC value determinations according to CLSI and EUCAST standards were rather complicated, since more than half of isolates tested showed a limited growth index, hampering endpoint determinations. We conclude that AST conditions including YNB as an assay medium, agitation of the plates, reading after 48 h of incubation, an inoculum size of 105CFU/ml, and incubation at 30°C made MIC determinations easier without an overestimation of MIC values.

scholarly journals Metabolic Engineering of Non-carotenoid-Producing Yeast Yarrowia lipolytica for the Biosynthesis of Zeaxanthin

2021 ◽  
Vol 12 ◽  
Author(s):  
Yuxiao Xie ◽  
Shulin Chen ◽  
Xiaochao Xiong
Keyword(s):  
Yarrowia Lipolytica ◽  
Fold Increase ◽  
Genetically Engineered ◽  
Cell Factory ◽  
Yeast Nitrogen Base ◽  
Nitrogen Base ◽  
Yeast Extract Peptone Dextrose ◽  
Dry Cell Weight ◽  
A Cell ◽  
Β Carotene

Zeaxanthin is vital to human health; thus, its production has received much attention, and it is also an essential precursor for the biosynthesis of other critical carotenoids such as astaxanthin and crocetin. Yarrowia lipolytica is one of the most intensively studied non-conventional yeasts and has been genetically engineered as a cell factory to produce carotenoids such as lycopene and β-carotene. However, zeaxanthin production by Y. lipolytica has not been well investigated. To fill this gap, β-carotene biosynthesis pathway has been first constructed in this study by the expression of genes, including crtE, crtB, crtI, and carRP. Three crtZ genes encoding β-carotene hydroxylase from different organisms were individually introduced into β-carotene-producing Y. lipolytica to evaluate their performance for producing zeaxanthin. The expression of crtZ from the bacterium Pantoea ananatis (formerly Erwinia uredovora, Eu-crtZ) resulted in the highest zeaxanthin titer and content on the basis of dry cell weight (DCW). After verifying the function of Eu-crtZ for producing zeaxanthin, the high-copy-number integration into the ribosomal DNA of Y. lipolytica led to a 4.02-fold increase in the titer of zeaxanthin and a 721% increase in the content of zeaxanthin. The highest zeaxanthin titer achieved 21.98 ± 1.80 mg/L by the strain grown on a yeast extract peptone dextrose (YPD)–rich medium. In contrast, the highest content of DCW reached 3.20 ± 0.11 mg/g using a synthetic yeast nitrogen base (YNB) medium to culture the cells. Over 18.0 g/L of citric acid was detected in the supernatant of the YPD medium at the end of cultivation. Furthermore, the zeaxanthin-producing strains still accumulated a large amount of lycopene and β-carotene. The results demonstrated the potential of a cell factory for zeaxanthin biosynthesis and opened up an avenue to engineer this host for the overproduction of carotenoids.

scholarly journals Correlation of Fluconazole MICs with Clinical Outcome in Cryptococcal Infection

2000 ◽  
Vol 44 (6) ◽  
pp. 1544-1548 ◽  
Author(s):  
A. I. Aller ◽  
E. Martin-Mazuelos ◽  
F. Lozano ◽  
J. Gomez-Mateos ◽  
L. Steele-Moore ◽  
...  
Keyword(s):  
Clinical Outcome ◽  
Maintenance Therapy ◽  
National Committee ◽  
Yeast Nitrogen Base ◽  
Nitrogen Base ◽  
Cryptococcal Infection ◽  
Microdilution Method ◽  
Cryptococcal Disease ◽  
Fluconazole Therapy

ABSTRACT We have correlated the in vitro results of testing the susceptibility of Cryptococcus neoformans to fluconazole with the clinical outcome after fluconazole maintenance therapy in patients with AIDS-associated cryptococcal disease. A total of 28 isolates of C. neoformans from 25 patients (24 AIDS patients) were tested. The MICs were determined by the broth microdilution technique by following the modified guidelines described in National Committee for Clinical Standards (NCCLS) document M27-A, e.g., use of yeast nitrogen base medium and a final inoculum of 104 CFU/ml. The fluconazole MIC at which 50% of isolates are inhibited (MIC50) and MIC90, obtained spectrophotometrically after 48 h of incubation, were 4 and 16 μg/ml, respectively. Of the 25 patients studied, 4 died of active cryptococcal disease and 2 died of other causes. Therapeutic failure was observed in five patients who were infected with isolates for which fluconazole MICs were ≥16 μg/ml. Four of these patients had previously had oropharyngeal candidiasis (OPC); three had previously had episodes of cryptococcal infection, and all five treatment failure patients had high cryptococcal antigen titers in either serum or cerebrospinal fluid (titers, >1:4,000). Although 14 of the 18 patients who responded to fluconazole therapy had previously had OPC infections, they each had only a single episode of cryptococcal infection. It appears that the clinical outcome after fluconazole maintenance therapy may be better when the infecting C. neoformans strain is inhibited by lower concentrations of fluconazole for eradication (MICs, <16 μg/ml) than when the patients are infected with strains that require higher fluconazole concentrations (MICs, ≥16 μg/ml). These findings also suggest that the MICs determined by the modified NCCLS microdilution method can be potential predictors of the clinical response to fluconazole therapy and may aid in the identification of patients who will not respond to fluconazole therapy.

scholarly journals Cell Surface Engineering of a β-Galactosidase for Galactooligosaccharide Synthesis

2009 ◽  
Vol 75 (18) ◽  
pp. 5938-5942 ◽  
Author(s):  
Yumei Li ◽  
Lili Lu ◽  
Hongmei Wang ◽  
Xiaodong Xu ◽  
Min Xiao
Keyword(s):  
Cell Surface ◽  
Surface Engineering ◽  
Yeast Cells ◽  
Penicillium Expansum ◽  
Yeast Nitrogen Base ◽  
Gene Encoding ◽  
Nitrogen Base ◽  
Reading Frame ◽  
Acid Protein ◽  
Casamino Acids

ABSTRACT A novel gene encoding transglycosylating β-galactosidase (BGase) was cloned from Penicillium expansum F3. The sequence contained a 3,036-bp open reading frame encoding a 1,011-amino-acid protein. This gene was subsequently expressed on the cell surface of Saccharomyces cerevisiae EBY-100 by galactose induction. The BGase-anchored yeast could directly utilize lactose to produce galactooligosaccharide (GOS), as well as the by-products glucose and a small quantity of galactose. The glucose was consumed by the yeast, and the galactose was used for BGase expression, thus greatly facilitating GOS synthesis. The GOS yield reached 43.64% when the recombinant yeast was cultivated in yeast nitrogen base-Casamino Acids medium containing 100 g/liter initial lactose at 25°C for 5 days. The yeast cells were harvested and recycled for the next batch of GOS synthesis. During sequential operations, both oligosaccharide synthesis and BGase expression were maintained at high levels with GOS yields of over 40%, and approximately 8 U/ml of BGase was detected in each batch.

scholarly journals EFFECT OF NIGELLA SATIVA SEED EXTRACT ON THE VIABILITY OF CANDIDA GLABRATA

2019 ◽  
pp. 84-87
Author(s):  
FARAH DIBA ◽  
RATNA FARIDA ◽  
SRI REDJEKI
Keyword(s):  
Candida Glabrata ◽  
Nigella Sativa ◽  
Artificial Saliva ◽  
Positive Control ◽  
Negative Control ◽  
Seed Extract ◽  
Yeast Nitrogen Base ◽  
Nitrogen Base ◽  
Common Opportunistic Infection ◽  
Yeast Nitrogen Base Medium

Objective: Candidiasis is a common opportunistic infection of the oral cavity caused by a yeast-like fungus called Candida. Candida glabrata is thesecond most frequently isolated species from this condition, after Candida albicans. This study aimed to evaluate the effect of Nigella sativa (blackcumin), known to possess antifungal properties, on the viability of C. glabrata.Methods: C. glabrata was added to a 96-microwell plate that was coated with artificial saliva and exposed to various concentrations (6.25%, 12.5%,25%, and 50%) of N. sativa seed extract; amphotericin B (250 mg/mL) was used as the positive control and 200 μL of yeast nitrogen base medium asthe negative control. The viability percentage of C. glabrata was determined by MTT assay.Results: The results showed that the viability values of C. glabrata were lower after exposure to the N. sativa seed extract when compared with thenegative control.Conclusion: The viability of Candida glabrata was decreased with increasing concentrations of the extract.

scholarly journals Saccharide sources do not influence the biofilm formation in Scedosporium/Lomentospora species

2020 ◽  
Vol 1 ◽  
Author(s):  
Thaís Pereira de Mello ◽  
Marta Helena Branquinha ◽  
André Luis Souza dos Santos
Keyword(s):  
Biofilm Formation ◽  
Culture Media ◽  
Yeast Nitrogen Base ◽  
Human Pathogens ◽  
Nitrogen Base ◽  
Opportunistic Fungi ◽  
Abiotic Surfaces ◽  
Resistance Patterns ◽  
Almost All ◽  
Glucose Supplementation

Abstract Scedosporium and Lomentospora species are ubiquitous saprophytic filamentous fungi that emerged as human pathogens with impressive multidrug-resistance profile. The ability to form biofilm over several biotic and abiotic surfaces is one of the characteristics that contributes to their resistance patterns against almost all currently available antifungals. Herein, we have demonstrated that Scedosporium apiospermum, Scedosporium minutisporum, Scedosporium aurantiacum and Lomentospora prolificans were able to form biofilm, in similar amounts, when conidial cells were incubated in a polystyrene substrate containing Sabouraud medium supplemented or not with different concentrations (2%, 5% and 10%) of glucose, fructose, sucrose and lactose. Likewise, the glucose supplementation of culture media primarily composed of amino acids (SCFM, synthetic cystic fibrosis medium) and salts (YNB, yeast nitrogen base) did not modulate the biofilm formation of Scedosporium/Lomentospora species. Collectively, the present data reinforce the ability of these opportunistic fungi to colonize and to build biofilm structures under different environmental conditions.

Effects on GSH synthesis in Chinese cabbage when the culturing solution is supplemented with ammonium sulfate or the constituent amino acids for glutathione

2005 ◽  
Vol 48 (4) ◽  
pp. 404-410 ◽  
Author(s):  
Ju-Sung Kim ◽  
Sang-Gyu Seo ◽  
Sun-Hyung Kim ◽  
Kenji Usui ◽  
Ie-Sung Shim
Keyword(s):  
Amino Acids ◽  
Ammonium Sulfate ◽  
Chinese Cabbage

The effect of ammonium sulfate on the solubility of amino acids in water at (298.15 and 323.15)K

2009 ◽  
Vol 41 (2) ◽  
pp. 193-196 ◽  
Author(s):  
Luísa A. Ferreira ◽  
Eugénia A. Macedo ◽  
Simão P. Pinho
Keyword(s):  
Amino Acids ◽  
Ammonium Sulfate

scholarly journals Fermentation of Dairy-Relevant Sugars by Saccharomyces, Kluyveromyces, and Brettanomyces: An Exploratory Study with Implications for the Utilization of Acid Whey, Part I

Fermentation ◽  
2021 ◽  
Vol 7 (4) ◽  
pp. 266
Author(s):  
Viviana K. Rivera Flores ◽  
Timothy A. DeMarsh ◽  
Patrick A. Gibney ◽  
Samuel D. Alcaine
Keyword(s):  
Value Added ◽  
Yeast Nitrogen Base ◽  
Sugar Consumption ◽  
Linear Modeling ◽  
Nitrogen Base ◽  
Fermentation Products ◽  
Significant Difference ◽  
Ethanol Yields ◽  
Acid Whey ◽  
Future Work

Acid whey from Greek-style yogurt (YAW) is an underutilized byproduct and a challenge for the dairy industry. One alternative is the fermentation of YAW by yeasts such as Saccharomyces, Brettanomyces, and Kluyveromyces spp., to produce new styles of fermented beverages. Previous research in our group suggested that the sugar profiles of the dairy coproducts impacted the fermentation profiles produced by B. claussenii. The present work aims to describe the fermentation of dairy sugars by S. cerevisiae, K. marxianus, and B. claussenii, under conditions comparable to those of YAW. For this purpose, four preparations of yeast nitrogen base, each containing 40 g/L of either lactose (LAC), glucose (GLU), galactose (GAL), or a 1:1 mixture of glucose and galactose (GLU:GAL), all at pH 4.20, were used as fermentation media. The fermentation was performed independently by each organism at 25 °C under anoxic conditions, while density, pH, cell count, ethanol, and organic acids were monitored. Non-linear modeling was used to characterize density curves, and Analysis of Variance and Tukey’s Honest Significant Difference tests were used to compare fermentation products. K. marxianus and S. cerevisiae displayed rapid sugar consumption with consistent ethanol yields in all media, as opposed to B. claussenii, which showed more variable results. The latter organism exhibited what appears to be a selective glucose fermentation in GLU:GAL, which will be explored in the future. These results provide a deeper understanding of dairy sugar utilization by relevant yeasts, allowing for future work to optimize fermentations to improve value-added beverage and ingredient production from YAW.

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