scholarly journals Management of Multiple Nitrogen Sources during Wine Fermentation by Saccharomyces cerevisiae

2017 ◽  
Vol 83 (5) ◽  
Author(s):  
Lucie Crépin ◽  
Nhat My Truong ◽  
Audrey Bloem ◽  
Isabelle Sanchez ◽  
Sylvie Dequin ◽  
...  

ABSTRACT During fermentative growth in natural and industrial environments, Saccharomyces cerevisiae must redistribute the available nitrogen from multiple exogenous sources to amino acids in order to suitably fulfill anabolic requirements. To exhaustively explore the management of this complex resource, we developed an advanced strategy based on the reconciliation of data from a set of stable isotope tracer experiments with labeled nitrogen sources. Thus, quantifying the partitioning of the N compounds through the metabolism network during fermentation, we demonstrated that, contrary to the generally accepted view, only a limited fraction of most of the consumed amino acids is directly incorporated into proteins. Moreover, substantial catabolism of these molecules allows for efficient redistribution of nitrogen, supporting the operative de novo synthesis of proteinogenic amino acids. In contrast, catabolism of consumed amino acids plays a minor role in the formation of volatile compounds. Another important feature is that the α-keto acid precursors required for the de novo syntheses originate mainly from the catabolism of sugars, with a limited contribution from the anabolism of consumed amino acids. This work provides a comprehensive view of the intracellular fate of consumed nitrogen sources and the metabolic origin of proteinogenic amino acids, highlighting a strategy of distribution of metabolic fluxes implemented by yeast as a means of adapting to environments with changing and scarce nitrogen resources. IMPORTANCE A current challenge for the wine industry, in view of the extensive competition in the worldwide market, is to meet consumer expectations regarding the sensory profile of the product while ensuring an efficient fermentation process. Understanding the intracellular fate of the nitrogen sources available in grape juice is essential to the achievement of these objectives, since nitrogen utilization affects both the fermentative activity of yeasts and the formation of flavor compounds. However, little is known about how the metabolism operates when nitrogen is provided as a composite mixture, as in grape must. Here we quantitatively describe the distribution through the yeast metabolic network of the N moieties and C backbones of these nitrogen sources. Knowledge about the management of a complex resource, which is devoted to improvement of the use of the scarce N nutrient for growth, will be useful for better control of the fermentation process and the sensory quality of wines.

2018 ◽  
Vol 84 (16) ◽  
Author(s):  
Vasileios Englezos ◽  
Luca Cocolin ◽  
Kalliopi Rantsiou ◽  
Anne Ortiz-Julien ◽  
Audrey Bloem ◽  
...  

ABSTRACTOver the last few years, the potential of non-Saccharomycesyeasts to improve the sensory quality of wine has been well recognized. In particular, the use ofStarmerella bacillarisin mixed fermentations withSaccharomyces cerevisiaewas reported as an appropriate way to enhance glycerol formation and reduce ethanol production. However, during sequential fermentation, many factors, such as the inoculation timing, strain combination, and physical and biochemical interactions, can affect yeast growth, the fermentation process, and/or metabolite synthesis. Among them, the availability of yeast-assimilable nitrogen (YAN), due to its role in the control of growth and fermentation, has been identified as a key parameter. Consequently, a comprehensive understanding of the metabolic specificities and the nitrogen requirements would be valuable to better exploit the potential ofStarm. bacillarisduring wine fermentation. In this study, marked differences in the consumption of the total and individual nitrogen sources were registered between the two species, while the twoStarm. bacillarisstrains generally behaved uniformly.Starm. bacillarisstrains are differentiated by their preferential uptake of ammonium compared with amino acids that are poorly assimilated or even produced (alanine). Otherwise, the non-Saccharomycesyeast exhibits low activity through the acetaldehyde pathway, which triggers an important redistribution of fluxes through the central carbon metabolic network. In particular, the formation of metabolites deriving from the two glycolytic intermediates glyceraldehyde-3-phosphate and pyruvate is substantially increased during fermentations byStarm. bacillaris. This knowledge will be useful to better control the fermentation process in mixed fermentation withStarm. bacillarisandS. cerevisiae.IMPORTANCEMixed fermentations using a controlled inoculation ofStarmerella bacillarisandSaccharomyces cerevisiaestarter cultures represent a feasible way to modulate wine composition that takes advantage of both the phenotypic specificities of the non-Saccharomycesstrain and the ability ofS. cerevisiaeto complete wine fermentation. However, according to the composition of grape juices, the consumption byStarm. bacillarisof nutrients, in particular of nitrogen sources, during the first stages of the process may result in depletions that further limit the growth ofS. cerevisiaeand lead to stuck or sluggish fermentations. Consequently, understanding the preferences of non-Saccharomycesyeasts for the nitrogen sources available in grape must together with their phenotypic specificities is essential for an efficient implementation of sequential wine fermentations withStarm. bacillarisandS. cerevisiaespecies. The results of our study demonstrate a clear preference for ammonium compared to amino acids for the non-Saccharomycesspecies. This finding underlines the importance of nitrogen sources, which modulate the functional characteristics of inoculated yeast strains to better control the fermentation process and product quality.


2020 ◽  
Vol 8 (6) ◽  
pp. 799
Author(s):  
Emilio M. Ungerfeld ◽  
M. Fernanda Aedo ◽  
Camila Muñoz ◽  
Natalie L. Urrutia ◽  
Emilio D. Martínez ◽  
...  

Ameliorating methane (CH4) emissions from ruminants would have environmental benefits, but it is necessary to redirect metabolic hydrogen ([H]) toward useful sinks to also benefit animal productivity. We hypothesized that inhibiting rumen methanogenesis would increase de novo synthesis of microbial amino acids (AA) as an alternative [H] sink if sufficient energy and carbon are provided. We examined the effects of inhibiting methanogenesis with 9, 10-anthraquione (AQ) on mixed rumen batch cultures growing on cellulose or starch as sources of energy and carbon contrasting in fermentability, with ammonium (NH4+) or trypticase (Try) as nitrogen (N) sources. Inhibiting methanogenesis with AQ inhibited digestion with cellulose but not with starch, and decreased propionate and increased butyrate molar percentages with both substrates. Inhibiting methanogenesis with 9, 10-anthraquinone increased de novo synthesis of microbial AA with starch but not with cellulose. The decrease in the recovery of [H] caused by the inhibition of methanogenesis was more moderate with starch due to an enhancement of butyrate and AA as [H] sinks. There may be an opportunity to simultaneously decrease the emissions of CH4 and N with some ruminant diets and replace plant protein supplements with less expensive non-protein nitrogen sources such as urea.


2015 ◽  
Vol 26 (4) ◽  
pp. 726-739 ◽  
Author(s):  
Bethany R. Cartwright ◽  
Derk D. Binns ◽  
Christopher L. Hilton ◽  
Sungwon Han ◽  
Qiang Gao ◽  
...  

Seipin is necessary for both adipogenesis and lipid droplet (LD) organization in nonadipose tissues; however, its molecular function is incompletely understood. Phenotypes in the seipin-null mutant of Saccharomyces cerevisiae include aberrant droplet morphology (endoplasmic reticulum–droplet clusters and size heterogeneity) and sensitivity of droplet size to changes in phospholipid synthesis. It has not been clear, however, whether seipin acts in initiation of droplet synthesis or at a later step. Here we utilize a system of de novo droplet formation to show that the absence of seipin results in a delay in droplet appearance with concomitant accumulation of neutral lipid in membranes. We also demonstrate that seipin is required for vectorial budding of droplets toward the cytoplasm. Furthermore, we find that the normal rate of droplet initiation depends on 14 amino acids at the amino terminus of seipin, deletion of which results in fewer, larger droplets that are consistent with a delay in initiation but are otherwise normal in morphology. Importantly, other functions of seipin, namely vectorial budding and resistance to inositol, are retained in this mutant. We conclude that seipin has dissectible roles in both promoting early LD initiation and in regulating LD morphology, supporting its importance in LD biogenesis.


2009 ◽  
Vol 52 (2) ◽  
pp. 449-455 ◽  
Author(s):  
Fátima de Cássia Oliveira Gomes ◽  
Roberta Amália de Carvalho Araújo ◽  
Patrícia Silva Cisalpino ◽  
Elizabeth Spangler Andrade Moreira ◽  
Carlos Leomar Zani ◽  
...  

Two Saccharomyces cerevisiae strains were tested as the starter yeasts in a traditional cachaça distillery. The strains used were S. cerevisiae UFMG-A829, isolated from a cachaça fermentation process, and S. cerevisiae K1-V1116, obtained from the wine industry. The permanence of each strain in the fermentation must was determined by RAPD (Random Amplified Polymorphic DNA)-PCR, with primer M13. Both yeast strains were prevalent in the vats for approximately 30 days. Indigenous non-Saccharomyces and indigenous S. cerevisiae strains were isolated in lower counts during the fermentation period. Indigenous S. cerevisiae strains were molecularly distinct when compared to the starter yeasts. The two yeasts appeared promising starter yeasts in the fermentation process to produce traditional cachaça.


Author(s):  
Frans Bianchi ◽  
Joury S. van’t Klooster ◽  
Stephanie J. Ruiz ◽  
Bert Poolman

SUMMARY We review the mechanisms responsible for amino acid homeostasis in Saccharomyces cerevisiae and other fungi. Amino acid homeostasis is essential for cell growth and survival. Hence, the de novo synthesis reactions, metabolic conversions, and transport of amino acids are tightly regulated. Regulation varies from nitrogen pool sensing to control by individual amino acids and takes place at the gene (transcription), protein (posttranslational modification and allostery), and vesicle (trafficking and endocytosis) levels. The pools of amino acids are controlled via import, export, and compartmentalization. In yeast, the majority of the amino acid transporters belong to the APC (amino acid-polyamine-organocation) superfamily, and the proteins couple the uphill transport of amino acids to the electrochemical proton gradient. Although high-resolution structures of yeast amino acid transporters are not available, homology models have been successfully exploited to determine and engineer the catalytic and regulatory functions of the proteins. This has led to a further understanding of the underlying mechanisms of amino acid sensing and subsequent downregulation of transport. Advances in optical microscopy have revealed a new level of regulation of yeast amino acid transporters, which involves membrane domain partitioning. The significance and the interrelationships of the latest discoveries on amino acid homeostasis are put in context.


2015 ◽  
Vol 3 (3) ◽  
pp. 439-442
Author(s):  
D.V. Surya Prakash ◽  
Meena Vangalapati

Chebulinic acid is a phenolic compound, commonly found in the Terminalia chebula, Phyllanthus emblica, Dimocarpus longan species etc. The enhancement of Chebulinic acid was obtained from the composition of medicinal herbs by using Baker’s yeast (Saccharomyces cerevisiae) under fermentation process. The optimum results were observed for the effect of % inoculum, substrate wt, incubation period, temperature, pH, carbon sources and nitrogen sources were 2.0ml, 6g, 48hr, 30oC, 4.0, sucrose and yeast extract respectively. The Chebulinic acid concentration enhanced from 3.4 to 6.8mg/ml for the optimised conditions. Int J Appl Sci Biotechnol, Vol 3(3): 439-442


2014 ◽  
Vol 2 (1) ◽  
pp. 41-44 ◽  
Author(s):  
Jarina Joshi

Ammonium sulphate, ammonium phosphate, sodium nitrate, urea and glycine were the five different commonly available nitrogen sources used at different concentration ranging from 0.5 to 4% w/v to produce ethanol in batch culture. Potato paste made from red potatoes grown in hilly regions of Nepal was used as carbon source. Prior to fermentation all carbon sources were saccharified enzymatically using α- amylase at pH 5 and temperature 55oC. Maximum yield of ethanol 5.2% was obtained at a temperature of 30oC and pH 5.0 without exogeneous supply of nitrogen. There is slight decrease in concentration when temperature is decreased to 25oC but a drastic decrease in concentration when temperature is increased beyond optimum. All the exogeneously supplied nitrogen sources found to enhance ethanol production and cell viability when yeast strain Saccharomyces cerevisiae isolated from brewer’s yeast was used. Ammonium sulphate was found as best nitrogen supplement among them. Maximum ethanol percentage of 8.3 was observed at pH 5.0 and temperature 30oC with Ammonium sulphate concentration of 2%.DOI: http://dx.doi.org/10.3126/ijasbt.v2i1.9191Int J Appl Sci Biotechnol, Vol. 2(1): 41-44


2002 ◽  
Vol 48 (11) ◽  
pp. 965-970 ◽  
Author(s):  
Javier Arrizon ◽  
Anne Gschaedler

In the tequila industry, fermentation is traditionally achieved at sugar concentrations ranging from 50 to 100 g·L–1. In this work, the behaviour of the Saccharomyces cerevisiae yeast (isolated from the juices of the Agave tequilana Weber blue variety) during the agave juice fermentation is compared at different sugar concentrations to determine if it is feasible for the industry to run fermentation at higher sugar concentrations. Fermentation efficiency is shown to be higher (above 90%) at a high concentration of initial sugar (170 g·L–1) when an additional source of nitrogen (a mixture of amino acids and ammonium sulphate, different than a grape must nitrogen composition) is added during the exponential growth phase.Key words: Saccharomyces cerevisiae, fermentation efficiency, nitrogen source, tequila.


2020 ◽  
Vol 8 (6) ◽  
pp. 904
Author(s):  
Ying Su ◽  
Pauline Seguinot ◽  
Audrey Bloem ◽  
Anne Ortiz-Julien ◽  
José María Heras ◽  
...  

Non-Saccharomyces yeast strains have become increasingly prevalent in the food industry, particularly in winemaking, because of their properties of interest both in biological control and in complexifying flavour profiles in end-products. However, unleashing the full potential of these species would require solid knowledge of their physiology and metabolism, which is, however, very limited to date. In this study, a quantitative analysis using 15N-labelled NH4Cl, arginine, and glutamine, and 13C-labelled leucine and valine revealed the specificities of the nitrogen metabolism pattern of two non-Saccharomyces species, Torulaspora delbrueckii and Metschnikowia pulcherrima. In T. delbrueckii, consumed nitrogen sources were mainly directed towards the de novo synthesis of proteinogenic amino acids, at the expense of volatile compounds production. This redistribution pattern was in line with the high biomass-producer phenotype of this species. Conversely, in M. pulcherrima, which displayed weaker growth capacities, a larger proportion of consumed amino acids was catabolised for the production of higher alcohols through the Ehrlich pathway. Overall, this comprehensive overview of nitrogen redistribution in T. delbrueckii and M. pulcherrima provides valuable information for a better management of co- or sequential fermentation combining these species with Saccharomyces cerevisiae.


2006 ◽  
Vol 5 (5) ◽  
pp. 816-824 ◽  
Author(s):  
Joanne M. Kingsbury ◽  
Alan L. Goldstein ◽  
John H. McCusker

ABSTRACT Saccharomyces cerevisiae is both an emerging opportunistic pathogen and a close relative of pathogenic Candida species. To better understand the ecology of fungal infection, we investigated the importance of pathways involved in uptake, metabolism, and biosynthesis of nitrogen and carbon compounds for survival of a clinical S. cerevisiae strain in a murine host. Potential nitrogen sources in vivo include ammonium, urea, and amino acids, while potential carbon sources include glucose, lactate, pyruvate, and fatty acids. Using mutants unable to either transport or utilize these compounds, we demonstrated that no individual nitrogen source was essential, while glucose was the most significant primary carbon source for yeast survival in vivo. Hydrolysis of the storage carbohydrate glycogen made a slight contribution for in vivo survival compared with a substantial requirement for trehalose hydrolysis. The ability to sense and respond to low glucose concentrations was also important for survival. In contrast, there was little or no requirement in vivo in this assay for any of the nitrogen-sensing pathways, nitrogen catabolite repression, the ammonium- or amino acid-sensing pathways, or general control. By using auxotrophic mutants, we found that some nitrogenous compounds (polyamines, methionine, and lysine) can be acquired from the host, while others (threonine, aromatic amino acids, isoleucine, and valine) must be synthesized by the pathogen. Our studies provide insights into the yeast-host environment interaction and identify potential antifungal drug targets.


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