scholarly journals Unique brewing-relevant properties of a strain of Saccharomyces jurei isolated from ash (Fraxinus excelsior)

2021 ◽  
Author(s):  
Mathias Hutzler ◽  
Maximilian Michel ◽  
Oliver Kunz ◽  
Tiina Kuusisto ◽  
Frederico Magalhães ◽  
...  
Keyword(s):  
Fraxinus Excelsior ◽  
Lag Phase ◽  
Tropical Fruit ◽  
Ethyl Hexanoate ◽  
Wild Yeast ◽  
Trained Panel ◽  
Application Potential ◽  
Maltose Utilization ◽  
Saccharomyces Eubayanus ◽  
High Level

AbstractThe successful application of Saccharomyces eubayanus and Saccharomyces paradoxus in brewery fermentations has highlighted the potential of wild yeast for brewing, and prompted investigation into the application potential of other members of the genus. Here, we evaluate, for the first time, the brewing potential of Saccharomyces jurei. The newly isolated strain from an ash tree (Fraxinus excelsior) in Upper Bavaria, Germany, close to the river Isar, was used to ferment a 12°P wort at 15°C. Performance was compared directly with that of a reference lager strain (TUM 34/70) and the S. eubayanus type strain. Both wild yeast rapidly depleted simple sugars and thereafter exhibited a lag phase before maltose utilization. This phase lasted for 4 and 10 days for S. eubayanus and S. jurei, respectively. S. eubayanus utilized fully the available maltose but, consistent with previous reports, did not use maltotriose. S. jurei, in contrast, utilized approx. 50% of the maltotriose available, making this the first report of maltotriose utilization in a wild Saccharomyces species. Maltotriose use was directly related to alcohol yield with 5.5, 4.9, and 4.5 % ABV produced by S. pastorianus, S. jurei and S. eubayanus. Beers also differed with respect to aroma volatiles, with a high level (0.4 mg/L) of the apple/aniseed aroma ethyl hexanoate in S. jurei beers, while S. eubayanus beers had a high level of phenylethanol (100 mg/L). A trained panel rated all beers as being of high quality, but noted clear differences. A phenolic spice/clove note was prominent in S. jurei beer. This was less pronounced in the S. eubayanus beers, despite analytical levels of 4-vinylguaiacol being similar. Tropical fruit notes were pronounced in S. jurei beers, possibly resulting from the high level of ethyl hexanoate. Herein, we present the successful results of the first intentional application of S. jurei as a yeast for beer fermentation known to us and compare its fermentation performance to other species of the genus. Results indicate considerable potential for S. jurei application in brewing, with clear advantages compared to other wild Saccharomyces species.

scholarly journals Unique Brewing-Relevant Properties of a Strain of Saccharomyces jurei Isolated From Ash (Fraxinus excelsior)

2021 ◽  
Vol 12 ◽  
Author(s):  
Mathias Hutzler ◽  
Maximilian Michel ◽  
Oliver Kunz ◽  
Tiina Kuusisto ◽  
Frederico Magalhães ◽  
...  
Keyword(s):  
Fraxinus Excelsior ◽  
Lag Phase ◽  
Tropical Fruit ◽  
Ethyl Hexanoate ◽  
Wild Yeast ◽  
Saccharomyces Pastorianus ◽  
Application Potential ◽  
Maltose Utilization ◽  
Saccharomyces Eubayanus ◽  
High Level

The successful application of Saccharomyces eubayanus and Saccharomyces paradoxus in brewery fermentations has highlighted the potential of wild Saccharomyes yeasts for brewing, and prompted investigation into the application potential of other members of the genus. Here, we evaluate, for the first time, the brewing potential of Saccharomyces jurei. The newly isolated strain from an ash tree (Fraxinus excelsior) in Upper Bavaria, Germany, close to the river Isar, was used to ferment a 12°P wort at 15°C. Performance was compared directly with that of a reference lager strain (TUM 34/70) and the S. eubayanus type strain. Both wild yeast rapidly depleted simple sugars and thereafter exhibited a lag phase before maltose utilization. This phase lasted for 4 and 10 days for S. eubayanus and S. jurei, respectively. S. eubayanus utilized fully the available maltose but, consistent with previous reports, did not use maltotriose. S. jurei, in contrast, utilized approximately 50% of the maltotriose available, making this the first report of maltotriose utilization in a wild Saccharomyces species. Maltotriose use was directly related to alcohol yield with 5.5, 4.9, and 4.5% ABV produced by Saccharomyces pastorianus, S. jurei, and S. eubayanus. Beers also differed with respect to aroma volatiles, with a high level (0.4 mg/L) of the apple/aniseed aroma ethyl hexanoate in S. jurei beers, while S. eubayanus beers had a high level of phenylethanol (100 mg/L). A trained panel rated all beers as being of high quality, but noted clear differences. A phenolic spice/clove note was prominent in S. jurei beer. This was less pronounced in the S. eubayanus beers, despite analytical levels of 4-vinylguaiacol being similar. Tropical fruit notes were pronounced in S. jurei beers, possibly resulting from the high level of ethyl hexanoate. Herein, we present results from the first intentional application of S. jurei as a yeast for beer fermentation (at the time of submission) and compare its fermentation performance to other species of the genus. Results indicate considerable potential for S. jurei application in brewing, with clear advantages compared to other wild Saccharomyces species.

scholarly journals The Transcriptional Factors MurR and Catabolite Activator Protein Regulate N-Acetylmuramic Acid Catabolism in Escherichia coli

2008 ◽  
Vol 190 (20) ◽  
pp. 6598-6608 ◽  
Author(s):  
Tina Jaeger ◽  
Christoph Mayer
Keyword(s):  
Escherichia Coli ◽  
Cell Wall ◽  
Sole Source ◽  
Lag Phase ◽  
Face To Face ◽  
E Coli ◽  
Catabolite Activator Protein ◽  
Activator Protein ◽  
High Level ◽  
First Time

ABSTRACT The MurNAc etherase MurQ of Escherichia coli is essential for the catabolism of the bacterial cell wall sugar N-acetylmuramic acid (MurNAc) obtained either from the environment or from the endogenous cell wall (i.e., recycling). High-level expression of murQ is required for growth on MurNAc as the sole source of carbon and energy, whereas constitutive low-level expression of murQ is sufficient for the recycling of peptidoglycan fragments continuously released from the cell wall during growth of the bacteria. Here we characterize for the first time the expression of murQ and its regulation by MurR, a member of the poorly characterized RpiR/AlsR family of transcriptional regulators. Deleting murR abolished the extensive lag phase observed for E. coli grown on MurNAc and enhanced murQ transcription some 20-fold. MurR forms a stable multimer (most likely a tetramer) and binds to two adjacent inverted repeats within an operator region. In this way MurR represses transcription from the murQ promoter and also interferes with its own transcription. MurNAc-6-phosphate, the substrate of MurQ, was identified as a specific inducer that weakens binding of MurR to the operator. Moreover, murQ transcription depends on the activation by cyclic AMP (cAMP)-catabolite activator protein (CAP) bound to a class I site upstream of the murQ promoter. murR and murQ are divergently orientated and expressed from nonoverlapping face-to-face (convergent) promoters, yielding transcripts that are complementary at their 5′ ends. As a consequence of this unusual promoter arrangement, cAMP-CAP also affects murR transcription, presumably by acting as a roadblock for RNA polymerase.

scholarly journals Complex Ancestries of Lager-Brewing Hybrids Were Shaped by Standing Variation in the Wild Yeast Saccharomyces eubayanus

PLoS Genetics ◽  
2016 ◽  
Vol 12 (7) ◽  
pp. e1006155 ◽  
Author(s):  
David Peris ◽  
Quinn K. Langdon ◽  
Ryan V. Moriarty ◽  
Kayla Sylvester ◽  
Martin Bontrager ◽  
...  
Keyword(s):  
Wild Yeast ◽  
Standing Variation ◽  
In The Wild ◽  
Saccharomyces Eubayanus

scholarly journals Release of Strawberry Aroma Compounds by Different Starch-Aroma Systems

2009 ◽  
Vol 27 (Special Issue 1) ◽  
pp. S58-S61 ◽  
Author(s):  
R. Vidrih ◽  
E. Zlatić ◽  
J. Hribar
Keyword(s):  
Guar Gum ◽  
Corn Starch ◽  
Cold Water ◽  
Solid Phase ◽  
Aroma Compounds ◽  
Aroma Release ◽  
Ethyl Hexanoate ◽  
Ethyl Butanoate ◽  
Trained Panel ◽  
Modified Starches

In the food industry, the addition of flavours is used to reinforce the aroma profile of different goods. However, interactions between starch and aroma compounds can occur, and this can impact upon aroma release and perception. In the present study, we have investigated the influence of starch type on aroma release from starch-aroma systems. The food model system used was composed of an aqueous starch dispersion (1 g dry starch/100 g dispersion) and 10 aroma compounds (ethyl butanoate, ethyl 2-methylbutanoate, ethyl 3-methylbutanoate, ethyl pentanoate, methyl hexanoate, ethyl hexanoate, methyl ethyl propanoate, hexyl acetate, 3-hexenol, and phenyl methyl acetate). Different commercially available starches were used: Amilogels P, K, PDP, G, MVK, HP, OK and HPW, and carrageenan (Amilogel CAR) and guar gum (Amilogel GG). Aroma release from these starch-aroma systems into the gas phase above food (headspace) were monitored by GC-MS analysis with a solid-phase micro-extraction technique. The smell of the starch-aroma system was also evaluated sensorially by a trained panel. The release of aroma compounds from the different starch-aroma systems was statistically significant (<I>P</I> < 0.0001) for all of the aroma compounds, with the exception of ethyl pentanoate. A correlation between the concentration of individual aroma compounds in the headspace and the sensory evaluation (smell) was seen. Starch-aroma systems comprising corn starch (Amilogel G), physically modified starches that are soluble in cold water (Amilogels K, PDP), and hydroxypropyl distarch phosphate (Amilogels HP) had sensorially superior smells compared to the other types of starches tested. At the same time, the headspace GC-MS analyses showed ethyl butanoate, ethyl 2-methylbutanoate, ethyl 3-methylbutanoate and ethyl pentanoate to be at the highest concentrations, which are all typical aroma compounds of strawberry fruit, and which also have low perception thresholds. Dextrin-roasted starch, guar gum and carrageenan provided the lowest sensory scores, although in contrast, they more strongly retained these aroma compounds.

scholarly journals Characterization and Dynamic Behavior of Wild Yeast during Spontaneous Wine Fermentation in Steel Tanks and Amphorae

2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Cecilia Díaz ◽  
Ana María Molina ◽  
Jörg Nähring ◽  
Rainer Fischer
Keyword(s):  
Dynamic Behavior ◽  
Fermentation Process ◽  
Pilot Scale ◽  
Wine Fermentation ◽  
Lag Phase ◽  
Wild Yeast ◽  
Spoilage Yeasts ◽  
Wild Yeasts ◽  
Red Grape ◽  
Grape Varieties

We studied the dynamic behavior of wild yeasts during spontaneous wine fermentation at a winery in the Valais region of Switzerland. Wild yeasts in the winery environment were characterized using a PCR-RFLP method. Up to 11 different yeast species were isolated from the vineyard air, whereas only seven were recovered from the grapes surface. We initially investigated a cultureindependent method in pilot-scale steel fermentation tanks and found a greater diversity of yeasts in the musts from two red grape varieties compared to three white grape varieties. We found that the yeastsMetschnikowia pulcherrima,Rhodotorula mucilaginosa,Pichia kluyveri,P. membranifaciensandSaccharomyces cerevisiaeremained active at the end of the fermentation. We also studied the dynamic behavior of yeasts in Qvevris for the first time using a novel, highlysensitive quantitative real-time PCR method. We found that non-Saccharomycesyeasts were present during the entire fermentation process, withR. mucilaginosaandP. anomalathe most prominent species. We studied the relationship between the predominance of different species and the output of the fermentation process. We identified so-called spoilage yeasts in all the fermentations, but high levels of acetic acid accumulated only in those fermentations with an extended lag phase.

Improved High-Quality Genome Assembly and Annotation of Pineapple (Ananas comosus) Cultivar MD2 Revealed Extensive Haplotype Diversity and Diversified FRS/FRF Gene Family

Genes ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 52
Author(s):  
Ashley G. Yow ◽  
Hamed Bostan ◽  
Raúl Castanera ◽  
Valentino Ruggieri ◽  
Molla F. Mengist ◽  
...  
Keyword(s):  
Gene Prediction ◽  
Haplotype Diversity ◽  
Fold Increase ◽  
Ananas Comosus ◽  
High Quality ◽  
Tropical Fruit ◽  
Related Sequence ◽  
New Genes ◽  
High Level ◽  
High Quality Genome

Pineapple (Ananas comosus (L.) Merr.) is the second most important tropical fruit crop globally, and ‘MD2’ is the most important cultivated variety. A high-quality genome is important for molecular-based breeding, but available pineapple genomes still have some quality limitations. Here, PacBio and Hi-C data were used to develop a new high-quality MD2 assembly and gene prediction. Compared to the previous MD2 assembly, major improvements included a 26.6-fold increase in contig N50 length, phased chromosomes, and >6000 new genes. The new MD2 assembly also included 161.6 Mb additional sequences and >3000 extra genes compared to the F153 genome. Over 48% of the predicted genes harbored potential deleterious mutations, indicating that the high level of heterozygosity in this species contributes to maintaining functional alleles. The genome was used to characterize the FAR1-RELATED SEQUENCE (FRS) genes that were expanded in pineapple and rice. Transposed and dispersed duplications contributed to expanding the numbers of these genes in the pineapple lineage. Several AcFRS genes were differentially expressed among tissue-types and stages of flower development, suggesting that their expansion contributed to evolving specialized functions in reproductive tissues. The new MD2 assembly will serve as a new reference for genetic and genomic studies in pineapple.

Temperature-Supported Forming of Automobile Related Magnesium Components

2013 ◽  
Author(s):  
Frank Schieck ◽  
Welf-Guntram Drossel ◽  
Hans Bräunlich ◽  
Sören Scheffler ◽  
Norbert Pierschel
Keyword(s):  
Lightweight Design ◽  
Construction Materials ◽  
Passenger Cars ◽  
Forming Simulation ◽  
Forming Technology ◽  
Related Part ◽  
Tailored Blanks ◽  
Application Potential ◽  
High Level ◽  
Forming Tools

Lightweight design in passenger cars is gaining more and more importance. Independent from conventionally or electrically drive train concepts, weight reduction is one of the most rated defining variables for fuel or energy consumption, thus affecting the range of the vehicle. Overall, the potential for using steel in lightweight bodywork construction has attained a high level of development with the result that the potential for further optimisation is increasingly diminishing. As a consequence, alternative lightweight construction materials are set to become more important in the future. Compared to the beneficial application potential regarding bending and distortion of steel- and Aluminium compared to Magnesium blanks, this material becomes more and more interesting for automobile applications. Beside challenges like corrosion and recycling, mainly an appropriate forming technology lies in the focus of investigations. Due to the insufficient forming conditions of Magnesium at room temperature the focus of investigation was related to the characterisation of material properties depending on temperature, the thermo-mechanical forming simulation for process and tool design and the practical realisation of complex, car-related part geometries as well as requirements for forming tools and additional devices. In the following article we will present the results of studies into the forming of magnesium sheets (AZ31) including tailored blanks, achieved within a growth cell (TeMaK and TeMaK+).

scholarly journals Brewing potential of the wild yeast species Saccharomyces paradoxus

2020 ◽  
Vol 246 (11) ◽  
pp. 2283-2297 ◽  
Author(s):  
Jarkko Nikulin ◽  
Virve Vidgren ◽  
Kristoffer Krogerus ◽  
Frederico Magalhães ◽  
Seija Valkeemäki ◽  
...  
Keyword(s):  
Pilot Scale ◽  
Lag Phase ◽  
Yeast Fermentation ◽  
Lager Yeast ◽  
Saccharomyces Paradoxus ◽  
Beer Brewing ◽  
Wild Yeast ◽  
Oak Trees ◽  
Wild Strains ◽  
Selling Point

Abstract Saccharomyces paradoxus is commonly isolated from environmental samples in Northern Europe and North America, but is rarely found associated with fermentation. However, as novelty has become a selling point in beer markets, interest toward non-conventional and local yeasts is increasing. Here, we report the first comprehensive investigation of the brewing potential of the species. Eight wild strains of S. paradoxus were isolated from oak trees growing naturally in Finland, screened in a series of fermentation trials and the most promising strain was selected for lager beer brewing at pilot scale (40 l). Yeasts were evaluated according to their ability to utilize wort sugars, their production of flavour-active aroma volatiles, diacetyl and organic acids, and sensorial quality of beers produced. All strains could assimilate maltose but this occurred after a considerable lag phase. Once adapted, most wild strains reached attenuation rates close to 70%. Adaptation to maltose could be maintained by re-pitching and with appropriate handling of the adapted yeast. Fermentation at 15 °C with the best performing strain was completed in 17 days. Maltose was consumed as efficiently as with a reference lager yeast, but no maltotriose use was observed. Bottled beers were evaluated by a trained sensory panel, and were generally rated as good as, or better than, reference beers. S. paradoxus beers were considered full-bodied and had a relatively clean flavour profile despite the presence of the clove-like 4-vinyl guaiacol. In conclusion, S. paradoxus exhibits a number of traits relevant to brewing, and with appropriate handling could be applied industrially.

scholarly journals Nanostructured Materials for Artificial Tissue Replacements

2020 ◽  
Vol 21 (7) ◽  
pp. 2521 ◽  
Author(s):  
Jana Pryjmaková ◽  
Markéta Kaimlová ◽  
Tomáš Hubáček ◽  
Václav Švorčík ◽  
Jakub Siegel
Keyword(s):  
Tissue Regeneration ◽  
Nano Particles ◽  
Porous Scaffolds ◽  
Current Trends ◽  
Organic Matrices ◽  
Application Potential ◽  
Inorganic Nanomaterials ◽  
High Level ◽  
Almost All ◽  
Organic Nanomaterials

This paper review current trends in applications of nanomaterials in tissue engineering. Nanomaterials applicable in this area can be divided into two groups: organic and inorganic. Organic nanomaterials are especially used for the preparation of highly porous scaffolds for cell cultivation and are represented by polymeric nanofibers. Inorganic nanomaterials are implemented as they stand or dispersed in matrices promoting their functional properties while preserving high level of biocompatibility. They are used in various forms (e.g., nano- particles, -tubes and -fibers)—and when forming the composites with organic matrices—are able to enhance many resulting properties (biologic, mechanical, electrical and/or antibacterial). For this reason, this contribution points especially to such type of composite nanomaterials. Basic information on classification, properties and application potential of single nanostructures, as well as complex scaffolds suitable for 3D tissues reconstruction is provided. Examples of practical usage of these structures are demonstrated on cartilage, bone, neural, cardiac and skin tissue regeneration and replacements. Nanomaterials open up new ways of treatments in almost all areas of current tissue regeneration, especially in tissue support or cell proliferation and growth. They significantly promote tissue rebuilding by direct replacement of damaged tissues.

scholarly journals Saccharomyces cerevisiaestrain YH166: a novel wild yeast for the production of tropical fruit sensory attributes in fermented beverages

2017 ◽  
Author(s):  
Kara Osburn ◽  
Robert Caputo ◽  
Justin Miller ◽  
Matthew L. Bochman
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Genetic Diversity ◽  
Genome Sequencing ◽  
Sensory Profile ◽  
Whole Genome ◽  
Brewing Industry ◽  
Tropical Fruit ◽  
Fermented Beverages ◽  
Wild Yeast ◽  
Phenotypic Variations

AbstractAll ales are fermented by various strains ofSaccharomyces cerevisiae.However, recent whole-genome sequencing has revealed that most commercially available ale yeasts are highly related and represent a small fraction of the genetic diversity found amongS. cerevisiaeisolates as a whole. This lack of diversity limits the phenotypic variations between these strains, which translates into a limited number of sensory compounds created during fermentation. Here, we characterized a collection of wildS. cerevisiae,S. kudriavzevii, andS. paradoxusstrains for their ability to ferment wort into beer. Although many isolates performed well,S. cerevisiaestrain YH166 was the most promising, displaying excellent fermentation kinetics and attenuation, as well as a tropical fruit sensory profile. Use of this strain in multiple styles of beer suggested that it is broadly applicable in the brewing industry. Thus, YH166 is a novel ale strain that can be used to lend fruity esters to beer and should pair well with citrusy hops in hop-forward ales.

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