Assimilable nitrogen utilisation and production of volatile and non-volatile compounds in chemically defined medium by Saccharomyces cerevisiae wine yeasts

Cells from stationary-phase cultures of two strains of Saccharomyces cerevisiae (3 and 20) failed to flocculate when grown in a complex or a chemically defined medium, while those of two other strains (11 and 13) flocculated when grown in either medium. Strain 30 flocculated when grown in complex but not defined medium and harvested from stationary-phase cultures. pH – electrophoretic mobility measurements on all five strains showed that mobility attributable to carboxyl groups usually increased as cultures progressed from the exponential to the stationary phase, while that caused by phosphate groups tended to decline. Acquisition of flocculating ability was accompanied in strains 11 and 30 by a slight increase in amidase activity, and greater increases compared with nonflocculent populations in activities of leucine aminopeptidase, α-mannosidase, and proteinase C. Activities of proteinases A and B showed no correlation with acquisition of flocculating ability.

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Tryptophan Derivatives by Saccharomyces cerevisiae EC1118: Evaluation, Optimization, and Production in a Soybean-Based Medium

International Journal of Molecular Sciences ◽

10.3390/ijms22010472 ◽

2021 ◽

Vol 22 (1) ◽

pp. 472

Author(s):

Michele Dei Cas ◽

Ileana Vigentini ◽

Sara Vitalini ◽

Antonella Laganaro ◽

Marcello Iriti ◽

...

Keyword(s):

Saccharomyces Cerevisiae ◽

Kynurenic Acid ◽

Potential Role ◽

Defined Medium ◽

The Other ◽

Chemically Defined Medium ◽

Cultural Medium ◽

Whole Cell Biotransformation ◽

Tryptophan Derivatives

Given the pharmacological properti es and the potential role of kynurenic acid (KYNA) in human physiology and the pleiotropic activity of the neurohormone melatonin (MEL) involved in physiological and immunological functions and as regulator of antioxidant enzymes, this study aimed at evaluating the capability of Saccharomyces cerevisiae EC1118 to release tryptophan derivatives (dTRPs) from the kynurenine (KYN) and melatonin pathways. The setting up of the spectroscopic and chromatographic conditions for the quantification of the dTRPs in LC-MS/MS system, the optimization of dTRPs’ production in fermentative and whole-cell biotransformation approaches and the production of dTRPs in a soybean-based cultural medium naturally enriched in tryptophan, as a case of study, were included in the experimental plan. Variable amounts of dTRPs, with a prevalence of metabolites of the KYN pathway, were detected. The LC-MS/MS analysis showed that the compound synthesized at highest concentration is KYNA that reached 9.146 ± 0.585 mg/L in fermentation trials in a chemically defined medium at 400 mg/L TRP. Further experiments in a soybean-based medium confirm KYNA as the main dTRPs, whereas the other dTRPs reached very lower concentrations. While detectable quantities of melatonin were never observed, two MEL isomers were successfully measured in laboratory media.

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Profile of Volatile Compounds of On-Farm Fermented and Dried Cocoa Beans Inoculated with Saccharomyces cerevisiae KY794742 and Pichia kudriavzevii KY794725

Molecules ◽

10.3390/molecules26020344 ◽

2021 ◽

Vol 26 (2) ◽

pp. 344

Author(s):

Gilson Celso Albuquerque Chagas Junior ◽

Nelson Rosa Ferreira ◽

Eloisa Helena de Aguiar Andrade ◽

Lidiane Diniz do Nascimento ◽

Francilia Campos de Siqueira ◽

...

Keyword(s):

Saccharomyces Cerevisiae ◽

Volatile Compounds ◽

Multivariate Analyses ◽

High Capacity ◽

Starter Cultures ◽

Cocoa Beans ◽

Pichia Kudriavzevii ◽

Fermentative Capacity ◽

Product Identity ◽

On Farm

This study aimed to identify the volatile compounds in the fermented and dried cocoa beans conducted with three distinct inoculants of yeast species due to their high fermentative capacity: Saccharomyces cerevisiae, Pichia kudriavzevii, the mixture in equal proportions 1:1 of both species, and a control fermentation (with no inoculum application). Three starter cultures of yeasts, previously isolated and identified in cocoa fermentation in the municipality of Tomé-Açu, Pará state, Brazil. The seeds with pulp were removed manually and placed in wooden boxes for the fermentation process that lasted from 6 to 7 days. On the last day of fermentation, the almonds were packaged properly and placed to dry (36 °C), followed by preparation for the analysis of volatile compounds by GC-MS technique. In addition to the control fermentation, a high capacity for the formation of desirable compounds in chocolate by the inoculants with P. kudriavzevii was observed, which was confirmed through multivariate analyses, classifying these almonds with the highest content of aldehydes, esters, ketones and alcohols and low concentration of off-flavours. We conclude that the addition of mixed culture starter can be an excellent alternative for cocoa producers, suggesting obtaining cocoa beans with desirable characteristics for chocolate production, as well as creating a product identity for the producing region.

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Effects by heme, insulin, and serum albumin on heme and protein synthesis in chick embryo liver cells cultured in a chemically defined medium, and a spectrofluorometric assay for porphyrin composition.

Journal of Biological Chemistry ◽

10.1016/s0021-9258(19)40633-9 ◽

1975 ◽

Vol 250 (24) ◽

pp. 9215-9225 ◽

Cited By ~ 5

Author(s):

S Granick ◽

P Sinclair ◽

S Sassa ◽

G Grieninger

Keyword(s):

Protein Synthesis ◽

Chick Embryo ◽

Serum Albumin ◽

Defined Medium ◽

Liver Cells ◽

Chemically Defined Medium ◽

Embryo Liver ◽

Cells Cultured

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Molecular Basis of Fructose Utilization by the Wine Yeast Saccharomyces cerevisiae: a Mutated HXT3 Allele Enhances Fructose Fermentation

Applied and Environmental Microbiology ◽

10.1128/aem.02269-06 ◽

2007 ◽

Vol 73 (8) ◽

pp. 2432-2439 ◽

Cited By ~ 67

Author(s):

Carole Guillaume ◽

Pierre Delobel ◽

Jean-Marie Sablayrolles ◽

Bruno Blondin

Keyword(s):

Saccharomyces Cerevisiae ◽

Molecular Basis ◽

Alcoholic Fermentation ◽

Wine Yeast ◽

Glycolytic Flux ◽

Hexose Transporter ◽

Wine Yeasts ◽

Yeast Saccharomyces Cerevisiae ◽

High Fructose ◽

Fructose Fermentation

ABSTRACT Fructose utilization by wine yeasts is critically important for the maintenance of a high fermentation rate at the end of alcoholic fermentation. A Saccharomyces cerevisiae wine yeast able to ferment grape must sugars to dryness was found to have a high fructose utilization capacity. We investigated the molecular basis of this enhanced fructose utilization capacity by studying the properties of several hexose transporter (HXT) genes. We found that this wine yeast harbored a mutated HXT3 allele. A functional analysis of this mutated allele was performed by examining expression in an hxt1-7Δ strain. Expression of the mutated allele alone was found to be sufficient for producing an increase in fructose utilization during fermentation similar to that observed in the commercial wine yeast. This work provides the first demonstration that the pattern of fructose utilization during wine fermentation can be altered by expression of a mutated hexose transporter in a wine yeast. We also found that the glycolytic flux could be increased by overexpression of the mutant transporter gene, with no effect on fructose utilization. Our data demonstrate that the Hxt3 hexose transporter plays a key role in determining the glucose/fructose utilization ratio during fermentation.

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