The yeast Saccharomyces cerevisiae- the main character in beer brewing.

Science.gov (United States)

Lodolo, Elizabeth J; Kock, Johan L F; Axcell, Barry C; Brooks, Martin

2008-11-01

Historically, mankind and yeast developed a relationship that led to the discovery of fermented beverages. Numerous inventions have led to improved technologies and capabilities to optimize fermentation technology on an industrial scale. The role of brewing yeast in the beer-making process is reviewed and its importance as the main character is highlighted. On considering the various outcomes of functions in a brewery, it has been found that these functions are focused on supporting the supply of yeast requirements for fermentation and ultimately to maintain the integrity of the product. The functions/processes include: nutrient supply to the yeast (raw material supply for brewhouse wort production); utilities (supply of water, heat and cooling); quality assurance practices (hygiene practices, microbiological integrity measures and other specifications); plant automation (vessels, pipes, pumps, valves, sensors, stirrers and centrifuges); filtration and packaging (product preservation until consumption); distribution (consumer supply); and marketing (consumer awareness). Considering this value chain of beer production and the 'bottle neck' during production, the spotlight falls on fermentation, the age-old process where yeast transforms wort into beer.

Comparison of DNA-based techniques for differentiation of production strains of ale and lager brewing yeast.

Science.gov (United States)

Kopecká, J; Němec, M; Matoulková, D

2016-06-01

Brewing yeasts are classified into two species-Saccharomyces pastorianus and Saccharomyces cerevisiae. Most of the brewing yeast strains are natural interspecies hybrids typically polyploids and their identification is thus often difficult giving heterogenous results according to the method used. We performed genetic characterization of a set of the brewing yeast strains coming from several yeast culture collections by combination of various DNA-based techniques. The aim of this study was to select a method for species-specific identification of yeast and discrimination of yeast strains according to their technological classification. A group of 40 yeast strains were characterized using PCR-RFLP analysis of ITS-5·8S, NTS, HIS4 and COX2 genes, multiplex PCR, RAPD-PCR of genomic DNA, mtDNA-RFLP and electrophoretic karyotyping. Reliable differentiation of yeast to the species level was achieved by PCR-RFLP of HIS4 gene. Numerical analysis of the obtained RAPD-fingerprints and karyotype revealed species-specific clustering corresponding with the technological classification of the strains. Taxonomic position and partial hybrid nature of strains were verified by multiplex PCR. Differentiation among species using the PCR-RFLP of ITS-5·8S and NTS region was shown to be unreliable. Karyotyping and RFLP of mitochondrial DNA evinced small inaccuracies in strain categorization. PCR-RFLP of HIS4 gene and RAPD-PCR of genomic DNA are reliable and suitable methods for fast identification of yeast strains. RAPD-PCR with primer 21 is a fast and reliable method applicable for differentiation of brewing yeasts with only 35% similarity of fingerprint profile between the two main technological groups (ale and lager) of brewing strains. It was proved that PCR-RFLP method of HIS4 gene enables precise discrimination among three technologically important Saccharomyces species. Differentiation of brewing yeast to the strain level can be achieved using the RAPD-PCR technique. © 2016 The

MALDI-TOF MS typing enables the classification of brewing yeasts of the genus Saccharomyces to major beer styles.

Science.gov (United States)

Lauterbach, Alexander; Usbeck, Julia C; Behr, Jürgen; Vogel, Rudi F

2017-01-01

Brewing yeasts of the genus Saccharomyces are either available from yeast distributor centers or from breweries employing their own "in-house strains". During the last years, the classification and characterization of yeasts of the genus Saccharomyces was achieved by using biochemical and DNA-based methods. The current lack of fast, cost-effective and simple methods to classify brewing yeasts to a beer type, may be closed by Matrix Assisted Laser Desorption/Ionization-Time-Of-Flight Mass Spectrometry (MALDI-TOF MS) upon establishment of a database based on sub-proteome spectra from reference strains of brewing yeasts. In this study an extendable "brewing yeast" spectra database was established including 52 brewing yeast strains of the most important types of bottom- and top-fermenting strains as well as beer-spoiling S. cerevisiae var. diastaticus strains. 1560 single spectra, prepared with a standardized sample preparation method, were finally compared against the established database and investigated by bioinformatic analyses for similarities and distinctions. A 100% separation between bottom-, top-fermenting and S. cerevisiae var. diastaticus strains was achieved. Differentiation between Alt and Kölsch strains was not achieved because of the high similarity of their protein patterns. Whereas the Ale strains show a high degree of dissimilarity with regard to their sub-proteome. These results were supported by MDS and DAPC analysis of all recorded spectra. Within five clusters of beer types that were distinguished, and the wheat beer (WB) cluster has a clear separation from other groups. With the establishment of this MALDI-TOF MS spectra database proof of concept is provided of the discriminatory power of this technique to classify brewing yeasts into different major beer types in a rapid, easy way, and focus brewing trails accordingly. It can be extended to yeasts for specialty beer types and other applications including wine making or baking.

MALDI-TOF MS typing enables the classification of brewing yeasts of the genus Saccharomyces to major beer styles.

Directory of Open Access Journals (Sweden)

Alexander Lauterbach

Full Text Available Brewing yeasts of the genus Saccharomyces are either available from yeast distributor centers or from breweries employing their own "in-house strains". During the last years, the classification and characterization of yeasts of the genus Saccharomyces was achieved by using biochemical and DNA-based methods. The current lack of fast, cost-effective and simple methods to classify brewing yeasts to a beer type, may be closed by Matrix Assisted Laser Desorption/Ionization-Time-Of-Flight Mass Spectrometry (MALDI-TOF MS upon establishment of a database based on sub-proteome spectra from reference strains of brewing yeasts. In this study an extendable "brewing yeast" spectra database was established including 52 brewing yeast strains of the most important types of bottom- and top-fermenting strains as well as beer-spoiling S. cerevisiae var. diastaticus strains. 1560 single spectra, prepared with a standardized sample preparation method, were finally compared against the established database and investigated by bioinformatic analyses for similarities and distinctions. A 100% separation between bottom-, top-fermenting and S. cerevisiae var. diastaticus strains was achieved. Differentiation between Alt and Kölsch strains was not achieved because of the high similarity of their protein patterns. Whereas the Ale strains show a high degree of dissimilarity with regard to their sub-proteome. These results were supported by MDS and DAPC analysis of all recorded spectra. Within five clusters of beer types that were distinguished, and the wheat beer (WB cluster has a clear separation from other groups. With the establishment of this MALDI-TOF MS spectra database proof of concept is provided of the discriminatory power of this technique to classify brewing yeasts into different major beer types in a rapid, easy way, and focus brewing trails accordingly. It can be extended to yeasts for specialty beer types and other applications including wine making or baking.

MALDI-TOF MS typing enables the classification of brewing yeasts of the genus Saccharomyces to major beer styles

Science.gov (United States)

Lauterbach, Alexander; Usbeck, Julia C.; Behr, Jürgen

2017-01-01

Brewing yeasts of the genus Saccharomyces are either available from yeast distributor centers or from breweries employing their own “in-house strains”. During the last years, the classification and characterization of yeasts of the genus Saccharomyces was achieved by using biochemical and DNA-based methods. The current lack of fast, cost-effective and simple methods to classify brewing yeasts to a beer type, may be closed by Matrix Assisted Laser Desorption/Ionization–Time-Of-Flight Mass Spectrometry (MALDI-TOF MS) upon establishment of a database based on sub-proteome spectra from reference strains of brewing yeasts. In this study an extendable “brewing yeast” spectra database was established including 52 brewing yeast strains of the most important types of bottom- and top-fermenting strains as well as beer-spoiling S. cerevisiae var. diastaticus strains. 1560 single spectra, prepared with a standardized sample preparation method, were finally compared against the established database and investigated by bioinformatic analyses for similarities and distinctions. A 100% separation between bottom-, top-fermenting and S. cerevisiae var. diastaticus strains was achieved. Differentiation between Alt and Kölsch strains was not achieved because of the high similarity of their protein patterns. Whereas the Ale strains show a high degree of dissimilarity with regard to their sub-proteome. These results were supported by MDS and DAPC analysis of all recorded spectra. Within five clusters of beer types that were distinguished, and the wheat beer (WB) cluster has a clear separation from other groups. With the establishment of this MALDI-TOF MS spectra database proof of concept is provided of the discriminatory power of this technique to classify brewing yeasts into different major beer types in a rapid, easy way, and focus brewing trails accordingly. It can be extended to yeasts for specialty beer types and other applications including wine making or baking. PMID

Effects of the usage of dried brewing yeast in the diets on the performance, egg traits and blood parameters in quails.

Science.gov (United States)

Yalçın, S; Erol, H; Ozsoy, B; Onbaşılar, I; Yalçın, S

2008-12-01

This experiment was carried out to determine the effects of the usage of dried brewing yeast in quail diets on laying performance, egg traits and blood parameters. A total of 240 Japanese quails (Coturnix coturnix japonica) aged 10 weeks were randomly allocated into one control group and three treatment groups. Each group was divided into five replicates as subgroups, comprising 12 quails each. Dried brewing yeast (Saccharomyces cerevisiae) was used at the levels of 1.5%, 3.0% and 4.5% in the diets of the first, second and third treatment groups, respectively. Soyabean meal was replaced with dried brewing yeast. The diets were formulated to be isocaloric and isonitrogenous. The experimental period lasted 18 weeks. Dietary treatments did not significantly affect body weight, daily feed intake, daily protein intake, egg production, egg weight, feed efficiency, mortality, egg shell thickness, egg albumen index, egg yolk index, egg Haugh unit, the percentages of egg shell, albumen and yolk, excreta moisture and small intestinal pH. Inclusion of 3% and 4.5% dried brewing yeast in diets reduced egg yolk cholesterol concentration as mg per yolk and mg per g yolk (P brewing yeast was significantly lower (P brewing yeast resulted in significant increases (P brewing yeast. It is concluded that dried brewing yeast can be used up to 4.5% in the diets of laying quails without adverse effects on the measured parameters.

Multi-locus genotyping of bottom fermenting yeasts by single nucleotide polymorphisms indicative of brewing characteristics.

Science.gov (United States)

Ikushima, Shigehito; Tateishi, Yoshiyuki; Kanai, Keiko; Shimada, Emiko; Tanaka, Misa; Ishiguro, Tatsuji; Mizutani, Satoru; Kobayashi, Osamu

2012-04-01

Yeast plays a capital role in brewing fermentation and has a direct impact on flavor and aroma. For the evaluation of competent brewing strains during quality control or development of novel strains it is standard practice to perform fermentation tests, which are costly and time-consuming. Here, we have categorized DNA markers which enable to distinguish and to screen brewing strains more efficiently than ever before. Sequence analysis at 289 loci in the genomes of six bottom fermenting Saccharomyces pastorianus strains revealed that 30 loci contained single nucleotide polymorphisms (SNPs). By determining the nucleotide sequences at the SNP-loci in 26 other S. pastorianus strains and 20 strains of the top fermenting yeast Saccharomyces cerevisiae, almost all these strains could be discriminated solely on the basis of the SNPs. By comparing the fermentative phenotypes of these strains we found that some DNA markers showed a strong association with brewing characteristics, such as the production of ethyl acetate and hydrogen sulphide (H2S). Therefore, the DNA markers we identified will facilitate quality control and the efficient development of brewing yeast strains. Copyright © 2011 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Relationship between ethanol and oxidative stress in laboratory and brewing yeast strains.

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Bleoanca, Iulia; Silva, Ana Rita Courelas; Pimentel, Catarina; Rodrigues-Pousada, Claudina; Menezes, Regina de Andrade

2013-12-01

Ethanol is a chemical stress factor that inhibits cellular growth and determines metabolic changes leading to reduction of cell viability during fermentation and yeast storage. To determine the effect of time, temperature and ethanol during storage of brewing yeasts we have monitored viability of cells stored for 72 h, at 6 °C or 12 °C, in the presence of various ethanol concentrations. Under the conditions tested, 6 °C is the most favourable temperature to store brewing yeast creams emphasizing the importance of a tight temperature control in the storage vessels. Because W210 is less resistant to storage in the presence of ethanol than W34/70, the optimal storage parameters obtained under our laboratory conditions vary significantly. The ale strain is sensitive to storage under ethanol concentrations higher than 5% (v/v) for more than 48 h at 6 °C whereas at the same temperature the lager strain tolerates ethanol up to 7.5% (v/v) for 72 h. Also, the viability assays indicate that the antioxidant protein Yap1 is an important factor to storage resistance of BY4741 laboratory strain. To investigate the molecular mechanisms underlying tolerance of brewing yeast strains to ethanol, we have performed phenotypic analysis, localization studies and have monitored the activation of antioxidant and protection genes as well as the intracellular contents of glycogen and trehalose. Overall, our data suggest that the ale strain W210 has a defective antioxidant defence system and that ethanol may induce the antioxidant defences as well as glycogen and trehalose protection mechanisms in laboratory and brewing yeast strains. Copyright © 2013 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Analysis of Growth Inhibition and Metabolism of Hydroxycinnamic Acids by Brewing and Spoilage Strains of Brettanomyces Yeast.

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Lentz, Michael; Harris, Chad

2015-10-15

Brettanomyces yeasts are well-known as spoilage organisms in both the wine and beer industries, but also contribute important desirable characters to certain beer styles. These properties are mediated in large part by Brettanomyces ' metabolism of hydroxycinnamic acids (HCAs) present in beverage raw materials. Here we compare growth inhibition by, and metabolism of, HCAs among commercial brewing strains and spoilage strains of B. bruxellensis and B. anomalus . These properties vary widely among the different strains tested and between the HCAs analyzed. Brewing strains showed more efficient metabolism of ferulic acid over p -coumaric acid, a trait not shared among the spoilage strains.

Analysis of Growth Inhibition and Metabolism of Hydroxycinnamic Acids by Brewing and Spoilage Strains of Brettanomyces Yeast

Directory of Open Access Journals (Sweden)

Michael Lentz

2015-10-01

Full Text Available Brettanomyces yeasts are well-known as spoilage organisms in both the wine and beer industries, but also contribute important desirable characters to certain beer styles. These properties are mediated in large part by Brettanomyces’ metabolism of hydroxycinnamic acids (HCAs present in beverage raw materials. Here we compare growth inhibition by, and metabolism of, HCAs among commercial brewing strains and spoilage strains of B. bruxellensis and B. anomalus. These properties vary widely among the different strains tested and between the HCAs analyzed. Brewing strains showed more efficient metabolism of ferulic acid over p-coumaric acid, a trait not shared among the spoilage strains.

Microbe domestication and the identification of the wild genetic stock of lager-brewing yeast

Science.gov (United States)

Libkind, Diego; Hittinger, Chris Todd; Valério, Elisabete; Gonçalves, Carla; Dover, Jim; Johnston, Mark; Gonçalves, Paula; Sampaio, José Paulo

2011-01-01

Domestication of plants and animals promoted humanity's transition from nomadic to sedentary lifestyles, demographic expansion, and the emergence of civilizations. In contrast to the well-documented successes of crop and livestock breeding, processes of microbe domestication remain obscure, despite the importance of microbes to the production of food, beverages, and biofuels. Lager-beer, first brewed in the 15th century, employs an allotetraploid hybrid yeast, Saccharomyces pastorianus (syn. Saccharomyces carlsbergensis), a domesticated species created by the fusion of a Saccharomyces cerevisiae ale-yeast with an unknown cryotolerant Saccharomyces species. We report the isolation of that species and designate it Saccharomyces eubayanus sp. nov. because of its resemblance to Saccharomyces bayanus (a complex hybrid of S. eubayanus, Saccharomyces uvarum, and S. cerevisiae found only in the brewing environment). Individuals from populations of S. eubayanus and its sister species, S. uvarum, exist in apparent sympatry in Nothofagus (Southern beech) forests in Patagonia, but are isolated genetically through intrinsic postzygotic barriers, and ecologically through host-preference. The draft genome sequence of S. eubayanus is 99.5% identical to the non-S. cerevisiae portion of the S. pastorianus genome sequence and suggests specific changes in sugar and sulfite metabolism that were crucial for domestication in the lager-brewing environment. This study shows that combining microbial ecology with comparative genomics facilitates the discovery and preservation of wild genetic stocks of domesticated microbes to trace their history, identify genetic changes, and suggest paths to further industrial improvement. PMID:21873232

Using Microsatellites to Identify Yeast Strains in Beer

OpenAIRE

Bruke, Alexandria; Van Brocklin, Jennifer; Rivest, Jason; Prenni, Jessica E.; Ibrahim, Hend

2012-01-01

Yeast is an integral part of the brewing process and is responsible for much of the taste and characteristics of beer. During the brewing process, yeast is subject to ageing and stress factors that can result in growth inhibition, decreased genetic stability, and changes in cell membrane stability. Characterization of yeast species used in industrial fermentation (e.g. S. cerevisiae) is of great importance to the brewing industry. The objective of this study was to develop an assay to identif...

Phenotypic and genetic diversity of Saccharomyces contaminants isolated from lager breweries and their phylogenetic relationship with brewing yeasts

DEFF Research Database (Denmark)

Jespersen, Lene; Kühle, Alis Van der Aa; Petersen, Kamilla M.

2000-01-01

-amplified intergenic transcribed spacer (ITS) regions. Chromosome length polymorphism (CLP) was evident among the Saccharomyces brewing contaminants with chromosome profiles typical of Saccharomyces sensu stricto. Based upon cluster analysis of their chromosome profiles the majority of the brewing contaminants could...... be grouped as either S. cerevisiae or S. pastorianus/S. bayanus. Further, the technique was able to differentiate between almost all brewing contaminants and to separate them from any specific lager brewing yeast. The diversity of the Saccharomyces brewing contaminants clearly demonstrated by their CLP...... in the SaccharomYces brewing contaminants indicate their adaptation to a maltose-enriched environment....

Yeast: the soul of beer's aroma--a review of flavour-active esters and higher alcohols produced by the brewing yeast.

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Pires, Eduardo J; Teixeira, José A; Brányik, Tomás; Vicente, António A

2014-03-01

Among the most important factors influencing beer quality is the presence of well-adjusted amounts of higher alcohols and esters. Thus, a heavy body of literature focuses on these substances and on the parameters influencing their production by the brewing yeast. Additionally, the complex metabolic pathways involved in their synthesis require special attention. More than a century of data, mainly in genetic and proteomic fields, has built up enough information to describe in detail each step in the pathway for the synthesis of higher alcohols and their esters, but there is still place for more. Higher alcohols are formed either by anabolism or catabolism (Ehrlich pathway) of amino acids. Esters are formed by enzymatic condensation of organic acids and alcohols. The current paper reviews the up-to-date knowledge in the pathways involving the synthesis of higher alcohols and esters by brewing yeasts. Fermentation parameters affecting yeast response during biosynthesis of these aromatic substances are also fully reviewed.

Immobilization: A Revolution in Traditional Brewing

Science.gov (United States)

Virkajärvi, Ilkka; Linko, Matti

In nature many micro-organisms tend to bind to solid surfaces. This tendency has long been utilized in a number of processes, for example in producing vinegar and acetic acid in bioreactors filled with wood shavings. Acetobacteria are attached to the surface of these shavings. In modern technical language: they are immobilized. Also yeast cells can be immobilized. In the brewing industry this has been the basis for maintaining efficient, continuous fermentation in bioreactors with very high yeast concentrations. The most dramatic change in brewing over recent years has been the replacement of traditional lagering of several weeks by a continuous process in which the residence time is only about 2h. Continuous primary fermentation is used on a commercial scale in New Zealand. In this process, instead of a carrier, yeast is retained in reactors by returning it partly after separation. In many pilot scale experiments the primary fermentation is shortened from about 1week to 1-2days using immobilized yeast reactors. When using certain genetically modified yeast strains no secondary fermentation is needed, and the total fermentation time in immobilized yeast reactors can therefore be shortened to only 2days.

Isolation and Characterization of a Gene Specific to Lager Brewing Yeast That Encodes a Branched-Chain Amino Acid Permease

Science.gov (United States)

Kodama, Yukiko; Omura, Fumihiko; Ashikari, Toshihiko

2001-01-01

We found two types of branched-chain amino acid permease gene (BAP2) in the lager brewing yeast Saccharomyces pastorianus BH-225 and cloned one type of BAP2 gene (Lg-BAP2), which is identical to that of Saccharomyces bayanus (by-BAP2-1). The other BAP2 gene of the lager brewing yeast (cer-BAP2) is very similar to the Saccharomyces cerevisiae BAP2 gene. This result substantiates the notion that lager brewing yeast is a hybrid of S. cerevisiae and S. bayanus. The amino acid sequence homology between S. cerevisiae Bap2p and Lg-Bap2p was 88%. The transcription of Lg-BAP2 was not induced by the addition of leucine to the growth medium, while that of cer-BAP2 was induced. The transcription of Lg-BAP2 was repressed by the presence of ethanol and weak organic acid, while that of cer-BAP2 was not affected by these compounds. Furthermore, Northern analysis during beer fermentation revealed that the transcription of Lg-BAP2 was repressed at the beginning of the fermentation, while cer-BAP2 was highly expressed throughout the fermentation. These results suggest that the transcription of Lg-BAP2 is regulated differently from that of cer-BAP2 in lager brewing yeasts. PMID:11472919

[IMPLEMENTATION OF MEASURES FOR OCCUPATIONAL HYGIENE AT ENTERPRISES OF BREWING INDUSTRY].

Science.gov (United States)

Agafonov, G V; Novikova, L V; Chusova, A E

2015-01-01

In the paper there are considered the legal basics of the occupational hygiene of brewing production: acts, bylaws and normative legal acts. There are characterized types of supervision and control (state, departmental, public) implementing the abidance of the sanitary legislation at the enterprises of the brewing industry. There are presented sanitary and hygienic requirements to the enterprises of the brewing industry. There are designated measures of occupational hygiene of brewing production: a sink, cleaning--removal of various pollutions, and also disinfection--process of the decline in quantity of microorganisms to safe level. There are considered some characteristics of pollutions which are subject to removal at various stages ofproduction of beer and stages of sanitary processing of brewing systems according to chemical properties of substances.

Designer Yeasts for the Fermentation Industry of the 21st Century

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Isak S. Pretorius

2003-01-01

Full Text Available The budding yeast, Saccharomyces cerevisiae, has enjoyed a long and distinguished history in the fermention industry. Owing to its efficiency in producing alcohol, S. cerevisiae is, without doubt, the most important commercial microorganism with GRAS (Generally Regarded As Safe status. By brewing beer and sparkling wine, mankind’s oldest domesticated organism made possible the world’s first biotechnological processes. With the emergence of modern molecular genetics, S. cerevisiae has again been harnessed to shift the frontiers of mankind’s newest revolution, genetic engineering. S. cerevisiae is at the forefront of many of these developments in modern biotechnology. Consequently, the industrial importance of S. cerevisiae has extended beyond traditional fermentation. Today, the products of yeast biotechnologies impinge on many commercially important sectors, including food, beverages, biofuels, chemicals, industrial enzymes, pharmaceuticals, agriculture and the environment. Nevertheless, since ethyl alcohol produced by yeast fermentation is likely to remain the foremost worldwide biotechnological commodity for the foreseeable future, this review focuses on advances made with respect to the development of tailor- made yeast strains for the fermented beverage and biofuel industries.

Performance factors of Czech brewing industry companies

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Gabriela Chmelíková

2013-01-01

Full Text Available The aim of this paper is to identify and subsequently quantify the intensity of relation between selected value drivers of Czech brewing industry companies and thus answer the question of what the significance level of partial indicators influencing the economic value added in the Czech brewing industry is. The aim was achieved by construction and application of multifactorial model for value generators explanation, which represents a synthesis of the INFA model and performance system Balanced Scorecard. The features typical for the first part of the model are algorithmized relations and financial character of the elements, while in the second with non-financial elements the ability of algorithmization is lost and the connection are defined solely on the basis of causality. This inconsistency also implied the difference in the character of analysis results. The proposed model made it possible to identify the most significant generators of value in the Czech brewing industry and it thus became an important guideline for brewery management. The results of the analysis offer a comprehensive overview of the most important value generators and thus enable the company managers to attain the goals of the owners more effectively.

Effects of the M&A Wave in the Global Brewing Industry 2000-2010

DEFF Research Database (Denmark)

Madsen, Erik Strøjer; Pedersen, Kurt; Lund-Thomsen, Lars

2012-01-01

The international beer brewing industry has experienced massive changes over the last decade. Industry concentration has increased dramatically, and the leading brewing groups have globalised their operations across virtually all continents. Industry consolidation has taken the shape of merger an...

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

Science.gov (United States)

Peris, David; Langdon, Quinn K; Moriarty, Ryan V; Sylvester, Kayla; Bontrager, Martin; Charron, Guillaume; Leducq, Jean-Baptiste; Landry, Christian R; Libkind, Diego; Hittinger, Chris Todd

2016-07-01

Lager-style beers constitute the vast majority of the beer market, and yet, the genetic origin of the yeast strains that brew them has been shrouded in mystery and controversy. Unlike ale-style beers, which are generally brewed with Saccharomyces cerevisiae, lagers are brewed at colder temperatures with allopolyploid hybrids of Saccharomyces eubayanus x S. cerevisiae. Since the discovery of S. eubayanus in 2011, additional strains have been isolated from South America, North America, Australasia, and Asia, but only interspecies hybrids have been isolated in Europe. Here, using genome sequence data, we examine the relationships of these wild S. eubayanus strains to each other and to domesticated lager strains. Our results support the existence of a relatively low-diversity (π = 0.00197) lineage of S. eubayanus whose distribution stretches across the Holarctic ecozone and includes wild isolates from Tibet, new wild isolates from North America, and the S. eubayanus parents of lager yeasts. This Holarctic lineage is closely related to a population with higher diversity (π = 0.00275) that has been found primarily in South America but includes some widely distributed isolates. A second diverse South American population (π = 0.00354) and two early-diverging Asian subspecies are more distantly related. We further show that no single wild strain from the Holarctic lineage is the sole closest relative of lager yeasts. Instead, different parts of the genome portray different phylogenetic signals and ancestry, likely due to outcrossing and incomplete lineage sorting. Indeed, standing genetic variation within this wild Holarctic lineage of S. eubayanus is responsible for genetic variation still segregating among modern lager-brewing hybrids. We conclude that the relationships among wild strains of S. eubayanus and their domesticated hybrids reflect complex biogeographical and genetic processes.

Saccharomyces cerevisiae variety diastaticus friend or foe?-spoilage potential and brewing ability of different Saccharomyces cerevisiae variety diastaticus yeast isolates by genetic, phenotypic and physiological characterization.

Science.gov (United States)

Meier-Dörnberg, Tim; Kory, Oliver Ingo; Jacob, Fritz; Michel, Maximilian; Hutzler, Mathias

2018-06-01

Saccharomyces cerevisiae variety diastaticus is generally considered to be an obligatory spoilage microorganism and spoilage yeast in beer and beer-mixed beverages. Their super-attenuating ability causes increased carbon dioxide concentrations, beer gushing and potential bottle explosion along with changes in flavor, sedimentation and increased turbidity. This research shows clear differences in the super-attenuating properties of S. cerevisiae var. diastaticus yeast strains and their potential for industrial brewing applications. Nineteen unknown spoilage yeast cultures were obtained as isolates and characterized using a broad spectrum of genetic and phenotypic methods. Results indicated that all isolates represent genetically different S. cerevisiae var. diastaticus strains except for strain TUM PI BA 124. Yeast strains were screened for their super-attenuating ability and sporulation. Even if the STA1 gene responsible for super-attenuation by encoding for the enzyme glucoamylase could be verified by real-time polymerase chain reaction, no correlation to the spoilage potential could be demonstrated. Seven strains were further characterized focusing on brewing and sensory properties according to the yeast characterization platform developed by Meier-Dörnberg. Yeast strain TUM 3-H-2 cannot metabolize dextrin and soluble starch and showed no spoilage potential or super-attenuating ability even when the strain belongs to the species S. cerevisiae var. diastaticus. Overall, the beer produced with S. cerevisiae var. diastaticus has a dry and winey body with noticeable phenolic off-flavors desirable in German wheat beers.

Effects of the M&A Wave in the Global Brewing Industry 2000-2010

DEFF Research Database (Denmark)

Madsen, Erik Strøjer; Pedersen, Kurt; Lund-Thomsen, Lars

2012-01-01

The international beer brewing industry has experienced massive changes over the last decade. Industry concentration has increased dramatically, and the leading brewing groups have globalised their operations across virtually all continents. Industry consolidation has taken the shape of merger...... and acquisition activity more than organic growth or international joint ventures. Based on a major data base the paper traces some causes and assesses the effects of M&A strategies in the global beer industry....

Evolutionary Engineering in Chemostat Cultures for Improved Maltotriose Fermentation Kinetics in Saccharomyces pastorianus Lager Brewing Yeast

Directory of Open Access Journals (Sweden)

Anja Brickwedde

2017-09-01

Full Text Available The lager brewing yeast Saccharomyces pastorianus, an interspecies hybrid of S. eubayanus and S. cerevisiae, ferments maltotriose, maltose, sucrose, glucose and fructose in wort to ethanol and carbon dioxide. Complete and timely conversion (“attenuation” of maltotriose by industrial S. pastorianus strains is a key requirement for process intensification. This study explores a new evolutionary engineering strategy for improving maltotriose fermentation kinetics. Prolonged carbon-limited, anaerobic chemostat cultivation of the reference strain S. pastorianus CBS1483 on a maltotriose-enriched sugar mixture was used to select for spontaneous mutants with improved affinity for maltotriose. Evolved populations exhibited an up to 5-fold lower residual maltotriose concentration and a higher ethanol concentration than the parental strain. Uptake studies with 14C-labeled sugars revealed an up to 4.75-fold higher transport capacity for maltotriose in evolved strains. In laboratory batch cultures on wort, evolved strains showed improved attenuation and higher ethanol concentrations. These improvements were also observed in pilot fermentations at 1,000-L scale with high-gravity wort. Although the evolved strain exhibited multiple chromosomal copy number changes, analysis of beer made from pilot fermentations showed no negative effects on flavor compound profiles. These results demonstrate the potential of evolutionary engineering for strain improvement of hybrid, alloploid brewing strains.

Evolutionary Engineering in Chemostat Cultures for Improved Maltotriose Fermentation Kinetics in Saccharomyces pastorianus Lager Brewing Yeast.

Science.gov (United States)

Brickwedde, Anja; van den Broek, Marcel; Geertman, Jan-Maarten A; Magalhães, Frederico; Kuijpers, Niels G A; Gibson, Brian; Pronk, Jack T; Daran, Jean-Marc G

2017-01-01

The lager brewing yeast Saccharomyces pastorianus , an interspecies hybrid of S. eubayanus and S. cerevisiae , ferments maltotriose, maltose, sucrose, glucose and fructose in wort to ethanol and carbon dioxide. Complete and timely conversion ("attenuation") of maltotriose by industrial S. pastorianus strains is a key requirement for process intensification. This study explores a new evolutionary engineering strategy for improving maltotriose fermentation kinetics. Prolonged carbon-limited, anaerobic chemostat cultivation of the reference strain S. pastorianus CBS1483 on a maltotriose-enriched sugar mixture was used to select for spontaneous mutants with improved affinity for maltotriose. Evolved populations exhibited an up to 5-fold lower residual maltotriose concentration and a higher ethanol concentration than the parental strain. Uptake studies with 14 C-labeled sugars revealed an up to 4.75-fold higher transport capacity for maltotriose in evolved strains. In laboratory batch cultures on wort, evolved strains showed improved attenuation and higher ethanol concentrations. These improvements were also observed in pilot fermentations at 1,000-L scale with high-gravity wort. Although the evolved strain exhibited multiple chromosomal copy number changes, analysis of beer made from pilot fermentations showed no negative effects on flavor compound profiles. These results demonstrate the potential of evolutionary engineering for strain improvement of hybrid, alloploid brewing strains.

[Synthesis and regulation of flavor compounds derived from brewing yeast: Esters].

Science.gov (United States)

Loviso, Claudia L; Libkind, Diego

2018-04-04

During brewing process yeast produce more than 500 chemical compounds that can negatively and positively impact beer at the organoleptic level. In recent years, and particularly thanks to the advancement of molecular biology and genomics, there has been considerable progress in our understanding about the molecular and cellular basis of the synthesis and regulation of many of these flavor compounds. This article focuses on esters, responsible for the floral and fruity beer flavor. Its formation depends on various enzymes and factors such as the concentration of wort nutrients, the amount of dissolved oxygen and carbon dioxide, fermentation temperature and mainly the genetics of the yeast used. We provide information about how the esters originate and how is the impact of different fermentative parameters on the final concentrations of these compounds and the quality of the end product. Copyright © 2018 The Authors. Publicado por Elsevier España, S.L.U. All rights reserved.

LABOUR PROTECTION AND SAFETY IN THE BREWING INDUSTRY

Directory of Open Access Journals (Sweden)

Irina Melnik

2016-10-01

Full Text Available The article describes the quantification of the level of safety in the brewing industry, which allows determining the contribution of each employee to ensure healthy and safe working conditions. Factors have also been shown to affect the safety of each of the employees. Knowledge of the characteristics and limits of each of the factors makes it possible to secure workflow and solve potential problems early. Previously considered a comprehensive approach that allows full control of the security protecting the entire brewing industry. Efficient and safe work is possible only if the working environment at the workplace to meet all the requirements of international standards in the field of occupational safety and health. Therefore, each category from a number of activities, which can significantly reduce the level of injury, and ending with the characteristics of each of the factors for drawing up a plan to ensure the maximum protection of the company's employees, was discussed. Chemical, physical, biological and psychophysical factors may exist alone or in combination with each other. It is therefore important to identify in advance all of them and to take all measures relating to ensure safe working conditions in each of the processes. Separately considered optimal and allowable values of temperature, relative humidity and air velocity in the working area of industrial premises. The parameters were established for the purpose of continuous monitoring in order to ensure comfortable and safe work environment for each employee. In some cases it is necessary to consult with technicians to get the full picture of the possible threats posed by each type of equipment. Especially dangerous in terms of occupational safety and health in the brewing industry is a cooking workshop, where the air temperature in the working area is significantly increased, as well as the bottling plant (noisy.

Brewing and volatiles analysis of three tea beers indicate a potential interaction between tea components and lager yeast.

Science.gov (United States)

Rong, Lei; Peng, Li-Juan; Ho, Chi-Tang; Yan, Shou-He; Meurens, Marc; Zhang, Zheng-Zhu; Li, Da-Xiang; Wan, Xiao-Chun; Bao, Guan-Hu; Gao, Xue-Ling; Ling, Tie-Jun

2016-04-15

Green tea, oolong tea and black tea were separately introduced to brew three kinds of tea beers. A model was designed to investigate the tea beer flavour character. Comparison of the volatiles between the sample of tea beer plus water mixture (TBW) and the sample of combination of tea infusion and normal beer (CTB) was accomplished by triangular sensory test and HS-SPME GC-MS analysis. The PCA of GC-MS data not only showed a significant difference between volatile features of each TBW and CTB group, but also suggested some key compounds to distinguish TBW from CTB. The results of GC-MS showed that the relative concentrations of many typical tea volatiles were significantly changed after the brewing process. More interestingly, the behaviour of yeast fermentation was influenced by tea components. A potential interaction between tea components and lager yeast could be suggested. Copyright © 2015 Elsevier Ltd. All rights reserved.

Vacuolar morphology of Saccharomyces cerevisiae during the process of wine making and Japanese sake brewing.

Science.gov (United States)

Izawa, Shingo; Ikeda, Kayo; Miki, Takeo; Wakai, Yoshinori; Inoue, Yoshiharu

2010-09-01

Although ethanol and osmotic stress affect the vacuolar morphology of Saccharomyces cerevisiae, little information is available about changes in vacuolar morphology during the processes of wine making and Japanese sake (rice wine) brewing. Here, we elucidated changes in the morphology of yeast vacuoles using Zrc1p-GFP, a vacuolar membrane protein, so as to better understand yeast physiology during the brewing process. Wine yeast cells (OC-2 and EC1118) contained highly fragmented vacuoles in the sake mash (moromi) as well as in the grape must. Although sake yeast cells (Kyokai no. 9 and no. 10) also contained highly fragmented vacuoles during the wine-making process, they showed quite a distinct vacuolar morphology during sake brewing. Since the environment surrounding sake yeast cells in the sake mash did not differ much from that surrounding wine yeast cells, the difference in vacuolar morphology during sake brewing between wine yeast and sake yeast was likely caused by innate characters.

The Microbiology of Malting and Brewing

Science.gov (United States)

Bokulich, Nicholas A.

2013-01-01

SUMMARY Brewing beer involves microbial activity at every stage, from raw material production and malting to stability in the package. Most of these activities are desirable, as beer is the result of a traditional food fermentation, but others represent threats to the quality of the final product and must be controlled actively through careful management, the daily task of maltsters and brewers globally. This review collates current knowledge relevant to the biology of brewing yeast, fermentation management, and the microbial ecology of beer and brewing. PMID:23699253

The microbiology of malting and brewing.

Science.gov (United States)

Bokulich, Nicholas A; Bamforth, Charles W

2013-06-01

Brewing beer involves microbial activity at every stage, from raw material production and malting to stability in the package. Most of these activities are desirable, as beer is the result of a traditional food fermentation, but others represent threats to the quality of the final product and must be controlled actively through careful management, the daily task of maltsters and brewers globally. This review collates current knowledge relevant to the biology of brewing yeast, fermentation management, and the microbial ecology of beer and brewing.

Valorization of beer brewing wastes by composting

OpenAIRE

Silva, Maria Elisabete; Brás, Isabel

2017-01-01

The aim of this work was to study the viability of recycling the residual yeast and diatomaceous earth (RYDE) slurry generated by the beer brewing industry by composting with animal manures, as well as to evaluate the quality of the composts obtained. Two pilot composting trials were carried out with different mixes: cow manure/RYDE slurry (Pile CM) and sheep manure/RYDE slurry (Pile SM). For all piles, wood chips were applied as bulking agent. The process was monitored b...

Relationship between competitiveness and operational and financial performance of firms: An exploratory study on the European brewing industry

Directory of Open Access Journals (Sweden)

Claudio Zanotti

2018-02-01

Originality/value: Significant relationships between competitive variables and financial performance in the brewing industry remains evasive in research thus far. Additionally, sustained in the potential the brewing industry represents within Europe, it is significant to identify these relationships for readers on both an academic and industrial background.

Screening for new brewing yeasts in the non-Saccharomyces sector with Torulaspora delbrueckii as model.

Science.gov (United States)

Michel, Maximilian; Kopecká, Jana; Meier-Dörnberg, Tim; Zarnkow, Martin; Jacob, Fritz; Hutzler, Mathias

2016-04-01

This study describes a screening system for future brewing yeasts focusing on non-Saccharomyces yeasts. The aim was to find new yeast strains that can ferment beer wort into a respectable beer. Ten Torulaspora delbrueckii strains were put through the screening system, which included sugar utilization tests, hop resistance tests, ethanol resistance tests, polymerase chain reaction fingerprinting, propagation tests, amino acid catabolism and anabolism, phenolic off-flavour tests and trial fermentations. Trial fermentations were analysed for extract reduction, pH drop, yeast concentration in bulk fluid and fermentation by-products. All investigated strains were able to partly ferment wort sugars and showed high tolerance to hop compounds and ethanol. One of the investigated yeast strains fermented all the wort sugars and produced a respectable fruity flavour and a beer of average ethanol content with a high volatile flavour compound concentration. Two other strains could possibly be used for pre-fermentation as a bio-flavouring agent for beers that have been post-fermented by Saccharomyces strains as a consequence of their low sugar utilization but good flavour-forming properties. Copyright © 2015 John Wiley & Sons, Ltd.

Marketing and Globalization of the Brewing Industry

DEFF Research Database (Denmark)

Madsen, Erik Strøjer; Wu, Yanqing

2016-01-01

The globalization of the brewing industry after the turn of the century through a large wave of mergers and acquisitions has changed the structure of the world beer markets. The chapter tracks the development in industry concentrations from 2002 to 2012 and points to high transportation costs...... for beers and economies of scale at the firm level in advertising and sales efforts as the main factors behind the wave of cross-country mergers and acquisitions. Using firm-level data from the largest breweries, the estimations verify significant economies of scale at the firm level in marketing...... significant economies of scale benefits at the firm level to be shared between the merging partners as marketing and distribution costs are very high in this industry....

Continuous primary fermentation of beer with yeast immobilized on spent grains : the effect of operational conditions

OpenAIRE

Brányik, Tomáš; Vicente, A. A.; Cruz, José Machado; Teixeira, J. A.

2004-01-01

A one-stage continuous primary beer fermentation with immobilized brewing yeast was studied. The objective of the work was to optimize the operational conditions (aeration and temperature) in terms of volumetric productivity and organoleptic quality of green beer. The system consisted of an internal-loop airlift reactor and a carrier material prepared from spent grains (a brewing by-product). An industrial wort and yeast strain were used. The immobilized biomass (in amounts from two to sevenf...

Production of freeze-dried yeast culture for the brewing of traditional sorghum beer, tchapalo.

Science.gov (United States)

N'Guessan, Florent K; Coulibaly, Hermann W; Alloue-Boraud, Mireille W A; Cot, Marlène; Djè, Koffi Marcellin

2016-01-01

Freeze-drying is a well-known dehydration method widely used to preserve microorganisms. In order to produce freeze-dried yeast starter culture for the brewing purpose of African sorghum beer, we tested protective agents (sucrose, glucose, glycerol) in combination with support materials (millet, maize, sorghum, and cassava flours) at 1:1 ratio (v/v). The yeast strains Saccharomyces cerevisiae F 12-7 and Candida tropicalis C 0-7 previously isolated from sorghum beer were used in a mixed culture at a ratio of 2:1 (C. tropicalis/S. cerevisiae). After the freeze-drying, the residual water contents were between 0.78 -2.27%, 0.55 -4.09%, and 0.40-2.61%, respectively, with sucrose, glucose and glycerol. The dried yeasts viabilities were between 4.0% and 10.6%. Among the protective agents used, sucrose was found to be the best protectant giving cell viabilities of 8.4-10.6%. Considering the support materials, millet flour was the best support after drying. When the freeze-dried yeast powders were stored at 4°C and room temperature (25-28°C) for up to 3 months, the survival rates were the highest with cassava flour as the support material.

Brewing with fractionated barley

NARCIS (Netherlands)

Donkelaar, van L.H.G.

2016-01-01

Brewing with fractionated barley

Beer is a globally consumed beverage, which is produced from malted barley, water, hops and yeast. In recent years, the use of unmalted barley and exogenous enzymes have become more popular because they enable simpler processing and reduced environmental

Inheritance of brewing-relevant phenotypes in constructed Saccharomyces cerevisiae × Saccharomyces eubayanus hybrids.

Science.gov (United States)

Krogerus, Kristoffer; Seppänen-Laakso, Tuulikki; Castillo, Sandra; Gibson, Brian

2017-04-21

Interspecific hybridization has proven to be a potentially valuable technique for generating de novo lager yeast strains that possess diverse and improved traits compared to their parent strains. To further enhance the value of hybridization for strain development, it would be desirable to combine phenotypic traits from more than two parent strains, as well as remove unwanted traits from hybrids. One such trait, that has limited the industrial use of de novo lager yeast hybrids, is their inherent tendency to produce phenolic off-flavours; an undesirable trait inherited from the Saccharomyces eubayanus parent. Trait removal and the addition of traits from a third strain could be achieved through sporulation and meiotic recombination or further mating. However, interspecies hybrids tend to be sterile, which impedes this opportunity. Here we generated a set of five hybrids from three different parent strains, two of which contained DNA from all three parent strains. These hybrids were constructed with fertile allotetraploid intermediates, which were capable of efficient sporulation. We used these eight brewing strains to examine two brewing-relevant phenotypes: stress tolerance and phenolic off-flavour formation. Lipidomics and multivariate analysis revealed links between several lipid species and the ability to ferment in low temperatures and high ethanol concentrations. Unsaturated fatty acids, such as oleic acid, and ergosterol were shown to positively influence growth at high ethanol concentrations. The ability to produce phenolic off-flavours was also successfully removed from one of the hybrids, Hybrid T2, through meiotic segregation. The potential application of these strains in industrial fermentations was demonstrated in wort fermentations, which revealed that the meiotic segregant Hybrid T2 not only didn't produce any phenolic off-flavours, but also reached the highest ethanol concentration and consumed the most maltotriose. Our study demonstrates the

Absence of fks1p in lager brewing yeast results in aberrant cell wall composition and improved beer flavor stability.

Science.gov (United States)

Wang, Jin-jing; Xu, Wei-na; Li, Xin'er; Li, Jia; Li, Qi

2014-06-01

The flavor stability during storage is very important to the freshness and shelf life of beer. However, beer fermented with a yeast strain which is prone to autolyze will significantly affect the flavor of product. In this study, the gene encoding β-1,3-glucan synthetase catalytic subunit (fks1) of the lager yeast was destroyed via self-clone strategy. β-1,3-glucan is the principle cell wall component, so fks1 disruption caused a decrease in β-1,3-glucan level and increase in chitin level in cell wall, resulting in the increased cell wall thickness. Comparing with wild-type strain, the mutant strain had 39.9 and 63.41 % less leakage of octanoic acid and decanoic acid which would significantly affect the flavor of beer during storage. Moreover, the results of European Brewery Convention tube fermentation test showed that the genetic manipulation to the industrial brewing yeast helped with the anti-staling ability, rather than affecting the fermentation ability. The thiobarbituric acid value reduced by 65.59 %, and the resistant staling value increased by 26.56 %. Moreover, the anti-staling index of the beer fermented with mutant strain increased by 2.64-fold than that from wild-type strain respectively. China has the most production and consumption of beer around the world, so the quality of beer has a significant impact on Chinese beer industry. The result of this study could help with the improvement of the quality of beer in China as well as around the world.

M&A as a driver of global competition in the brewing industry

DEFF Research Database (Denmark)

Madsen, Erik Strøjer; Pedersen, Kurt; Lund-Thomsen, Lars

The international beer brewing industry has experienced massive changes over the last decade. Industry concentration has increased dramatically, and the leading brewer groups have globalised their operations across virtually all continents. The paper describes the development and puts it into an ...... it into an industrial economics framework. Based on a major data base the paper further assesses the effects of M&A strategies in the global beer industry....

Biogas Production from Brewer’s Yeast Using an Anaerobic Sequencing Batch Reactor

OpenAIRE

Zupančič, Gregor Drago; Panjičko, Mario; Zelić, Bruno

2017-01-01

Renewable energy sources are becoming increasingly important in the beverage and food industries. In the brewing industry, a significant percentage of the used raw materials finishes the process as secondary resource or waste. The research on the anaerobic digestion of brewer’s yeast has been scarce until recent years. One of the reasons for this is its use as a secondary resource in the food industry and as cattle feed. Additionally, market value of brewer’s yeast is higher than its energy v...

Immobilized cell technology in beer brewing: Current experience and results

Directory of Open Access Journals (Sweden)

Leskošek-Čukalov Ida J.

2005-01-01

Full Text Available Immobilized cell technology (ICT has been attracting continual attention in the brewing industry over the past 30 years. Some of the reasons are: faster fermentation rates and increased volumetric productivity, compared to those of traditional beer production based on freely suspended cells, as well as the possibility of continuous operation. Nowadays, ICT technology is well established in secondary fermentation and alcohol- free and low-alcohol beer production. In main fermentation, the situation is more complex and this process is still under scrutiny on both the lab and pilot levels. The paper outlines the most important ICT processes developed for beer brewing and provides an overview of carrier materials, bioreactor design and examples of their industrial applications, as well as some recent results obtained by our research group. We investigated the possible applications of polyvinyl alcohol in the form of LentiKats®, as a potential porous matrices carrier for beer fermentation. Given are the results of growth studies of immobilized brewer's yeast Saccharomyces uvarum and the kinetic parameters obtained by using alginate microbeads with immobilized yeast cells and suspension of yeast cells as controls. The results indicate that the immobilization procedure in LentiKat® carriers has a negligible effect on cell viability and growth. The apparent specific growth rate of cells released in medium was comparable to that of freely suspended cells, implying preserved cell vitality. A series of batch fermentations performed in shaken flasks and an air-lift bioreactor indicated that the immobilized cells retained high fermentation activity. The full attenuation in green beer was reached after 48 hours in shaken flasks and less than 24 hours of fermentation in gas-lift bioreactors.

FINANCIAL MARKET REACTIONS TO INTERNATIONAL MERGERS & ACQUISITIONS IN THE BREWING INDUSTRY: AN EVENT STUDY ANALYSIS

OpenAIRE

Heyder, Matthias; Ebneth, Oliver; Theuvsen, Ludwig

2008-01-01

Cross-border acquisitions have been the growing trend in recent years in the world brewing industry, giving brewers the opportunity to enhance their degree of internationalization and market share remarkably. This study employs event study analysis to examine 31 mergers and acquisitions among leading European brewing groups. Differences regarding financial market reactions can be determined within the European peer group. Managerial implications as well as future research propositions conclud...

Global Gene Expression Analysis of Yeast Cells during Sake Brewing▿ †

Science.gov (United States)

Wu, Hong; Zheng, Xiaohong; Araki, Yoshio; Sahara, Hiroshi; Takagi, Hiroshi; Shimoi, Hitoshi

2006-01-01

During the brewing of Japanese sake, Saccharomyces cerevisiae cells produce a high concentration of ethanol compared with other ethanol fermentation methods. We analyzed the gene expression profiles of yeast cells during sake brewing using DNA microarray analysis. This analysis revealed some characteristics of yeast gene expression during sake brewing and provided a scaffold for a molecular level understanding of the sake brewing process. PMID:16997994

Genomic reconstruction to improve bioethanol and ergosterol production of industrial yeast Saccharomyces cerevisiae.

Science.gov (United States)

Zhang, Ke; Tong, Mengmeng; Gao, Kehui; Di, Yanan; Wang, Pinmei; Zhang, Chunfang; Wu, Xuechang; Zheng, Daoqiong

2015-02-01

Baker's yeast (Saccharomyces cerevisiae) is the common yeast used in the fields of bread making, brewing, and bioethanol production. Growth rate, stress tolerance, ethanol titer, and byproducts yields are some of the most important agronomic traits of S. cerevisiae for industrial applications. Here, we developed a novel method of constructing S. cerevisiae strains for co-producing bioethanol and ergosterol. The genome of an industrial S. cerevisiae strain, ZTW1, was first reconstructed through treatment with an antimitotic drug followed by sporulation and hybridization. A total of 140 mutants were selected for ethanol fermentation testing, and a significant positive correlation between ergosterol content and ethanol production was observed. The highest performing mutant, ZG27, produced 7.9 % more ethanol and 43.2 % more ergosterol than ZTW1 at the end of fermentation. Chromosomal karyotyping and proteome analysis of ZG27 and ZTW1 suggested that this breeding strategy caused large-scale genome structural variations and global gene expression diversities in the mutants. Genetic manipulation further demonstrated that the altered expression activity of some genes (such as ERG1, ERG9, and ERG11) involved in ergosterol synthesis partly explained the trait improvement in ZG27.

Enhancement of ethanol fermentation in Saccharomyces cerevisiae sake yeast by disrupting mitophagy function.

Science.gov (United States)

Shiroma, Shodai; Jayakody, Lahiru Niroshan; Horie, Kenta; Okamoto, Koji; Kitagaki, Hiroshi

2014-02-01

Saccharomyces cerevisiae sake yeast strain Kyokai no. 7 has one of the highest fermentation rates among brewery yeasts used worldwide; therefore, it is assumed that it is not possible to enhance its fermentation rate. However, in this study, we found that fermentation by sake yeast can be enhanced by inhibiting mitophagy. We observed mitophagy in wild-type sake yeast during the brewing of Ginjo sake, but not when the mitophagy gene (ATG32) was disrupted. During sake brewing, the maximum rate of CO2 production and final ethanol concentration generated by the atg32Δ laboratory yeast mutant were 7.50% and 2.12% higher than those of the parent strain, respectively. This mutant exhibited an improved fermentation profile when cultured under limiting nutrient concentrations such as those used during Ginjo sake brewing as well as in minimal synthetic medium. The mutant produced ethanol at a concentration that was 2.76% higher than the parent strain, which has significant implications for industrial bioethanol production. The ethanol yield of the atg32Δ mutant was increased, and its biomass yield was decreased relative to the parent sake yeast strain, indicating that the atg32Δ mutant has acquired a high fermentation capability at the cost of decreasing biomass. Because natural biomass resources often lack sufficient nutrient levels for optimal fermentation, mitophagy may serve as an important target for improving the fermentative capacity of brewery yeasts.

Interaction Between Yeasts and Zinc

Science.gov (United States)

Nicola, Raffaele De; Walker, Graeme

Zinc is an essential trace element in biological systems. For example, it acts as a cellular membrane stabiliser, plays a critical role in gene expression and genome modification and activates nearly 300 enzymes, including alcohol dehydrogenase. The present chapter will be focused on the influence of zinc on cell physiology of industrial yeast strains of Saccharomyces cerevisiae, with special regard to the uptake and subsequent utilisation of this metal. Zinc uptake by yeast is metabolism-dependent, with most of the available zinc translocated very quickly into the vacuole. At cell division, zinc is distributed from mother to daughter cells and this effectively lowers the individual cellular zinc concentration, which may become zinc depleted at the onset of the fermentation. Zinc influences yeast fermentative performance and examples will be provided relating to brewing and wine fermentations. Industrial yeasts are subjected to several stresses that may impair fermentation performance. Such stresses may also impact on yeast cell zinc homeostasis. This chapter will discuss the practical implications for the correct management of zinc bioavailability for yeast-based biotechnologies aimed at improving yeast growth, viability, fermentation performance and resistance to environmental stresses

Progress in Brewing Science and Beer Production.

Science.gov (United States)

Bamforth, C W

2017-06-07

The brewing of beer is an ancient biotechnology, the unit processes of which have not changed in hundreds of years. Equally, scientific study within the brewing industry not only has ensured that modern beer making is highly controlled, leading to highly consistent, high-quality, healthful beverages, but also has informed many other fermentation-based industries.

Genetic relationship and biological status of the industrially important yeast Saccharomyces eubayanus Sampaio et al.

Science.gov (United States)

Naumov, G I

2017-03-01

The genomes of the recently discovered yeast Saccharomyces eubayanus and traditional S. cerevisiae are known to be found in the yeast S. pastorianus (syn. S. carlsbergensis), which are essential for brewing. The cryotolerant yeast S. bayanus var. uvarum is of great importance for production of some wines. Based on ascospore viability and meiotic recombination of the control parental markers in hybrids, we have shown that there is no complete interspecies post-zygotic isolation between the yeasts S. eubayanus, S. bayanus var. bayanus and S. bayanus var. uvarum. The genetic data presented indicate that all of the three taxa belong to the same species.

[Overexpression of FKS1 to improve yeast autolysis-stress].

Science.gov (United States)

Li, Jia; Wang, Jinjing; Li, Qi

2015-09-01

With the development of high gravity brewing, yeast cells are exposed to multiple brewing-associated stresses, such as increased osmotic pressure, enhanced alcohol concentration and nutritional imbalance. These will speed up yeast autolysis, which seriously influence beer flavor and quality. To increase yeast anti-autolytic ability, FKS1 overexpression strain was constructed by 18S rDNA. The concentration of β-1,3-glucan of overexpression strain was 62% higher than that of wild type strain. Meantime, FKS1 overexpression strain increased anti-stress ability at 8% ethanol, 0.4 mol/L NaCl and starvation stress. Under simulated autolysis, FKS1 showed good anti-autolytic ability by slower autolysis. These results confirms the potential of FKS1 overexpression to tackle yeast autolysis in high-gravity brewing.

The role of lager beer yeast in oxidative stability of model beer

DEFF Research Database (Denmark)

Berner, Torben Sune; Arneborg, Nils

2012-01-01

that the oxidative stress resistance was strain dependent. Fermentation of model wort in European Brewing Convention tubes using three yeast strains with varying oxidative stress resistances resulted in three model beers with different rates of radical formation as measured by electron spin resonance in forced......AIMS: In this study, we investigated the relationship between the ability of lager brewing yeast strains to tolerate oxidative stress and their ability to produce oxidative stable model beer. METHODS AND RESULTS: Screening of 21 lager brewing yeast strains against diamide and paraquat showed...... in the model beers. CONCLUSIONS: A more oxidative stable beer is not obtained by a more-oxidative-stress-tolerant lager brewing yeast strain, exhibiting a higher secretion of thioredoxin, but rather by a less-oxidative-stress-tolerant strain, exhibiting a higher iron uptake. SIGNIFICANCE AND IMPACT...

Yeast flocculation: New story in fuel ethanol production.

Science.gov (United States)

Zhao, X Q; Bai, F W

2009-01-01

Yeast flocculation has been used in the brewing industry to facilitate biomass recovery for a long time, and thus its mechanism of yeast flocculation has been intensively studied. However, the application of flocculating yeast in ethanol production garnered attention mainly in the 1980s and 1990s. In this article, updated research progress in the molecular mechanism of yeast flocculation and the impact of environmental conditions on yeast flocculation are reviewed. Construction of flocculating yeast strains by genetic approach and utilization of yeast flocculation for ethanol production from various feedstocks were presented. The concept of self-immobilized yeast cells through their flocculation is revisited through a case study of continuous ethanol fermentation with the flocculating yeast SPSC01, and their technical and economic advantages are highlighted by comparing with yeast cells immobilized with supporting materials and regular free yeast cells as well. Taking the flocculating yeast SPSC01 as an example, the ethanol tolerance of the flocculating yeast was also discussed.

Technological Development of Brewing in Domestic Refrigerator Using Freeze-Dried Raw Materials

Directory of Open Access Journals (Sweden)

Angelika-Ioanna Gialleli

2017-01-01

Full Text Available Development of a novel directly marketable beer brewed at low temperature in a domestic refrigerator combined with yeast immobilization technology is presented in this study. Separately, freeze-dried wort and immobilized cells of the cryotolerant yeast strain Saccharomyces cerevisiae AXAZ-1 on tubular cellulose were used in low-temperature fermentation (2, 5 and 7 °C. The positive eff ect of tubular cellulose during low-temperature brewing was examined, revealing that freeze-dried immobilized yeast cells on tubular cellulose signifi cantly reduced the fermentation rates in contrast to freeze-dried free cells, although they are recommended for home-made beer production. Immobilization also enhanced the yeast resistance at low-temperature fermentation, reducing the minimum brewing temperature value from 5 to 2 °C. In the case of high-quality beer production, the eff ect of temperature and initial sugar concentration on the fermentation kinetics were assessed. Sensory enrichment of the produced beer was confi rmed by the analysis of the fi nal products, revealing a low diacetyl concentration, together with improved polyphenol content, aroma profi le and clarity. The proposed process for beer production in a domestic refrigerator can easily be commercialized and applied by dissolving the content of two separate packages in tap water; one package containing dried wort and the other dried immobilized cells on tubular cellulose suspended in tap water.

Technological Development of Brewing in Domestic Refrigerator Using Freeze-Dried Raw Materials.

Science.gov (United States)

Gialleli, Angelika-Ioanna; Ganatsios, Vassilios; Terpou, Antonia; Kanellaki, Maria; Bekatorou, Argyro; Koutinas, Athanasios A; Dimitrellou, Dimitra

2017-09-01

Development of a novel directly marketable beer brewed at low temperature in a domestic refrigerator combined with yeast immobilization technology is presented in this study. Separately, freeze-dried wort and immobilized cells of the cryotolerant yeast strain Saccharomyces cerevisiae AXAZ-1 on tubular cellulose were used in low-temperature fermentation (2, 5 and 7 °C). The positive effect of tubular cellulose during low-temperature brewing was examined, revealing that freeze-dried immobilized yeast cells on tubular cellulose significantly reduced the fermentation rates in contrast to freeze-dried free cells, although they are recommended for home-made beer production. Immobilization also enhanced the yeast resistance at low-temperature fermentation, reducing the minimum brewing temperature value from 5 to 2 °C. In the case of high-quality beer production, the effect of temperature and initial sugar concentration on the fermentation kinetics were assessed. Sensory enrichment of the produced beer was confirmed by the analysis of the final products, revealing a low diacetyl concentration, together with improved polyphenol content, aroma profile and clarity. The proposed process for beer production in a domestic refrigerator can easily be commercialized and applied by dissolving the content of two separate packages in tap water; one package containing dried wort and the other dried immobilized cells on tubular cellulose suspended in tap water.

100 Years Jubilee for the discovery of the enzymes in yeast

DEFF Research Database (Denmark)

Berg, Rolf W.

1997-01-01

The work by Prof. E. Buchner 100 years ago which led to the discovery of the enzymes in yeast for brewing beer is reviewed.......The work by Prof. E. Buchner 100 years ago which led to the discovery of the enzymes in yeast for brewing beer is reviewed....

Progress Report Natsurv 1 K5_2285/3 The Malt Brewing Industry

CSIR Research Space (South Africa)

Ramukhwatho, Fhumulani R

2014-07-01

Full Text Available of brewing process cycle The generic brewing processes for beer production (Varman and Sutherland, 1994; Unicer, SA, 2005) 5 Breweries Classification Large = 10 Medium = ? Small = 77 Per Barrel produced: Large: > 6 000 000 Medium: ≥ 15 000 ≤ 6... in study 10 Loci of Malt Breweries in SA 11 Key Brewing Processes Brewing Fermentation Storage Bottling Barrelling 12 Preliminary Results from Questionnaire/ literature • Results based on 8 responses (breweries) • Data to date was synthesized...

Between science and industry-applied yeast research.

Science.gov (United States)

Korhola, Matti

2018-03-01

I was fortunate to enter yeast research at the Alko Research Laboratories with a strong tradition in yeast biochemistry and physiology studies. At the same time in the 1980s there was a fundamental or paradigm change in molecular biology research with discoveries in DNA sequencing and other analytical and physical techniques for studying macromolecules and cells. Since that time biotechnological research has expanded the traditional fermentation industries to efficient production of industrial and other enzymes and specialty chemicals. Our efforts were directed towards improving the industrial production organisms: minerals enriched yeasts (Se, Cr, Zn) and high glutathione content yeast, baker´s, distiller´s, sour dough and wine yeasts, and the fungal Trichoderma reesei platform for enzyme production. I am grateful for the trust of my colleagues in several leadership positions at the Alko Research Laboratories, Yeast Industry Platform and at the international yeast community.

Flocculation in ale brewing strains of Saccharomyces cerevisiae: re-evaluation of the role of cell surface charge and hydrophobicity.

Science.gov (United States)

Holle, Ann Van; Machado, Manuela D; Soares, Eduardo V

2012-02-01

Flocculation is an eco-friendly process of cell separation, which has been traditionally exploited by the brewing industry. Cell surface charge (CSC), cell surface hydrophobicity (CSH) and the presence of active flocculins, during the growth of two (NCYC 1195 and NCYC 1214) ale brewing flocculent strains, belonging to the NewFlo phenotype, were examined. Ale strains, in exponential phase of growth, were not flocculent and did not present active flocculent lectins on the cell surface; in contrast, the same strains, in stationary phase of growth, were highly flocculent (>98%) and presented a hydrophobicity of approximately three to seven times higher than in exponential phase. No relationship between growth phase, flocculation and CSC was observed. For comparative purposes, a constitutively flocculent strain (S646-1B) and its isogenic non-flocculent strain (S646-8D) were also used. The treatment of ale brewing and S646-1B strains with pronase E originated a loss of flocculation and a strong reduction of CSH; S646-1B pronase E-treated cells displayed a similar CSH as the non-treated S646-8D cells. The treatment of the S646-8D strain with protease did not reduce CSH. In conclusion, the increase of CSH observed at the onset of flocculation of ale strains is a consequence of the presence of flocculins on the yeast cell surface and not the cause of yeast flocculation. CSH and CSC play a minor role in the auto-aggregation of the ale strains since the degree of flocculation is defined, primarily, by the presence of active flocculins on the yeast cell wall.

Production of astaxanthin rich feed supplement for animals from Phaffia rhodozyma yeast at low cost

Science.gov (United States)

Irtiza, Ayesha; Shatunova, Svetlana; Glukhareva, Tatiana; Kovaleva, Elena

2017-09-01

Dietary nutrients such as amino acids, vitamins, minerals and antioxidants can play a significant role in determining meat quality and also the growth rate of poultry or animal. Phaffia rhodozyma was grown on waste from brewery industry to produce astaxanthin rich feed supplements at a very low cost. Phaffia rhodozyma is yeast specie that has ability to produce carotenoids and approximately 80% of its total carotenoid content is astaxanthin, which is highly valuable carotenoid for food, feed and aquaculture industry. This study was carried out to test yeast extract of spent yeast from brewing industry waste (residual yeast) as potential nitrogen source for growth of Phaffia rhodozyma. Cultivation was carried out in liquid media prepared by yeast extracts and other components (glucose and peptone). Carotenoids from the biomass were released into biomass by suspending cells in DMSO for destruction of cells followed by extraction with petroleum ether. The extracted carotenoids were studied by spectrophotometry to identify and quantify astaxanthin and other carotenoids produced.

Modifications of Saccharomyces pastorianus cell wall polysaccharides with brewing process.

Science.gov (United States)

Bastos, Rita; Coelho, Elisabete; Coimbra, Manuel A

2015-06-25

The cell wall polysaccharides of brewers spent yeast Saccharomyces pastorianus (BSY) and the inoculum yeast (IY) were studied in order to understand the changes induced by the brewing process. The hot water and alkali extractions performed solubilized mainly mannoproteins, more branched for BSY than those of IY. Also, (31)P solid state NMR showed that the BSY mannoproteins were 3 times more phosphorylated. By electron microscopy it was observed that the final residues of alkali sequential extraction until 4M KOH preserved the yeast three-dimensional structure. The final residues, composed mainly by glucans (92%), showed that the BSY, when compared with IY, contained higher amount of (1→4)-linked Glc (43% for BSY and 16% for IY) and lower (1→3)-linked Glc (17% for BSY and 42% for IY). The enzymatic treatment of final residue showed that both BSY and IY had (α1→4)-linked Glc and (β1→4)-linked Glc, in a 2:1 ratio, showing that S. pastorianus increases their cellulose-like linkages with the brewing process. Copyright © 2015 Elsevier Ltd. All rights reserved.

Distinct Domestication Trajectories in Top-Fermenting Beer Yeasts and Wine Yeasts.

Science.gov (United States)

Gonçalves, Margarida; Pontes, Ana; Almeida, Pedro; Barbosa, Raquel; Serra, Marta; Libkind, Diego; Hutzler, Mathias; Gonçalves, Paula; Sampaio, José Paulo

2016-10-24

Beer is one of the oldest alcoholic beverages and is produced by the fermentation of sugars derived from starches present in cereal grains. Contrary to lager beers, made by bottom-fermenting strains of Saccharomyces pastorianus, a hybrid yeast, ale beers are closer to the ancient beer type and are fermented by S. cerevisiae, a top-fermenting yeast. Here, we use population genomics to investigate (1) the closest relatives of top-fermenting beer yeasts; (2) whether top-fermenting yeasts represent an independent domestication event separate from those already described; (3) whether single or multiple beer yeast domestication events can be inferred; and (4) whether top-fermenting yeasts represent non-recombinant or recombinant lineages. Our results revealed that top-fermenting beer yeasts are polyphyletic, with a main clade composed of at least three subgroups, dominantly represented by the German, British, and wheat beer strains. Other beer strains were phylogenetically close to sake, wine, or bread yeasts. We detected genetic signatures of beer yeast domestication by investigating genes previously linked to brewing and using genome-wide scans. We propose that the emergence of the main clade of beer yeasts is related with a domestication event distinct from the previously known cases of wine and sake yeast domestication. The nucleotide diversity of the main beer clade more than doubled that of wine yeasts, which might be a consequence of fundamental differences in the modes of beer and wine yeast domestication. The higher diversity of beer strains could be due to the more intense and different selection regimes associated to brewing. Copyright © 2016 Elsevier Ltd. All rights reserved.

Chromosomal Copy Number Variation in Saccharomyces pastorianus Is Evidence for Extensive Genome Dynamics in Industrial Lager Brewing Strains.

Science.gov (United States)

van den Broek, M; Bolat, I; Nijkamp, J F; Ramos, E; Luttik, M A H; Koopman, F; Geertman, J M; de Ridder, D; Pronk, J T; Daran, J-M

2015-09-01

Lager brewing strains of Saccharomyces pastorianus are natural interspecific hybrids originating from the spontaneous hybridization of Saccharomyces cerevisiae and Saccharomyces eubayanus. Over the past 500 years, S. pastorianus has been domesticated to become one of the most important industrial microorganisms. Production of lager-type beers requires a set of essential phenotypes, including the ability to ferment maltose and maltotriose at low temperature, the production of flavors and aromas, and the ability to flocculate. Understanding of the molecular basis of complex brewing-related phenotypic traits is a prerequisite for rational strain improvement. While genome sequences have been reported, the variability and dynamics of S. pastorianus genomes have not been investigated in detail. Here, using deep sequencing and chromosome copy number analysis, we showed that S. pastorianus strain CBS1483 exhibited extensive aneuploidy. This was confirmed by quantitative PCR and by flow cytometry. As a direct consequence of this aneuploidy, a massive number of sequence variants was identified, leading to at least 1,800 additional protein variants in S. pastorianus CBS1483. Analysis of eight additional S. pastorianus strains revealed that the previously defined group I strains showed comparable karyotypes, while group II strains showed large interstrain karyotypic variability. Comparison of three strains with nearly identical genome sequences revealed substantial chromosome copy number variation, which may contribute to strain-specific phenotypic traits. The observed variability of lager yeast genomes demonstrates that systematic linking of genotype to phenotype requires a three-dimensional genome analysis encompassing physical chromosomal structures, the copy number of individual chromosomes or chromosomal regions, and the allelic variation of copies of individual genes. Copyright © 2015, van den Broek et al.

New lager yeast strains generated by interspecific hybridization.

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Krogerus, Kristoffer; Magalhães, Frederico; Vidgren, Virve; Gibson, Brian

2015-05-01

The interspecific hybrid Saccharomyces pastorianus is the most commonly used yeast in brewery fermentations worldwide. Here, we generated de novo lager yeast hybrids by mating a domesticated and strongly flocculent Saccharomyces cerevisiae ale strain with the Saccharomyces eubayanus type strain. The hybrids were characterized with respect to the parent strains in a wort fermentation performed at temperatures typical for lager brewing (12 °C). The resulting beers were analysed for sugar and aroma compounds, while the yeasts were tested for their flocculation ability and α-glucoside transport capability. These hybrids inherited beneficial properties from both parent strains (cryotolerance, maltotriose utilization and strong flocculation) and showed apparent hybrid vigour, fermenting faster and producing beer with higher alcohol content (5.6 vs 4.5 % ABV) than the parents. Results suggest that interspecific hybridization is suitable for production of novel non-GM lager yeast strains with unique properties and will help in elucidating the evolutionary history of industrial lager yeast.

The use of chitooligosaccharide in beer brewing for protection against beer-spoilage bacteria and its influence on beer performance.

Science.gov (United States)

Zhao, Xue; Yu, Zhimin; Wang, Ting; Guo, Xuan; Luan, Jing; Sun, Yumei; Li, Xianzhen

2016-04-01

To identify a biological preservative that can protect beer from microbial contamination, which often results in the production of turbidity and off-flavor. The antimicrobial activity of a chitooligosaccharide against beer-spoilage bacteria and its effect on the fermentation performance of brewer's yeast was studied. Chitooligosaccharide with an average 2 kDa molecular weight was the best at inhibiting all tested beer-spoilage bacteria. The application of chitooligosaccharide in the brewing process did not influence the fermentation of brewer's yeast. The change in beer performance induced by the contamination of Lactobacillus brevis could be effectively controlled by application of chitooligosaccharide in the beer brewing process. The experimental data suggested that chitooligosaccharide should be an excellent preservative to inhibit beer-spoilage bacteria in the brewing process and in the end product.

Learning by Brewing: Beer Production Experiments in the Chemical Engineering Laboratory

Science.gov (United States)

Cerretani, Colin; Kelkile, Esayas; Landry, Alexandra

2017-01-01

We discuss the successful creation and implementation of a biotechnology track within the chemical engineering unit operations course. The track focuses on engineering principles relevant to brewing. Following laboratory modules investigating heat transfer processes and yeast fermentation kinetics, student groups design and implement a project to…

Monitoring of metabolites and by-products in a down-scaled industrial lager beer fermentation

OpenAIRE

Sjöström, Fredrik

2013-01-01

The sugar composition of the wort and how these sugars are utilised by the yeast affects the organoleptic properties of the beer. To monitor the saccharides in the wort before inoculation and during fermentation is important in modern brewing industry. Reducing the duration of the brewing process is valuable and can be achieved by reducing the fermentation time by an increase in temperature. However, this must be done without changing the quality and characteristics of the end product, anothe...

Industrial brewing yeast engineered for the production of primary flavor determinants in hopped beer

DEFF Research Database (Denmark)

Denby, Charles M.; Li, Rachel A.; Vu, Van T.

2018-01-01

Flowers of the hop plant provide both bitterness and "hoppy" flavor to beer. Hops are, however, both a water and energy intensive crop and vary considerably in essential oil content, making it challenging to achieve a consistent hoppy taste in beer. Here, we report that brewer's yeast can...... be engineered to biosynthesize aromatic monoterpene molecules that impart hoppy flavor to beer by incorporating recombinant DNA derived from yeast, mint, and basil. Whereas metabolic engineering of biosynthetic pathways is commonly enlisted to maximize product titers, tuning expression of pathway enzymes...

Influence of brewing conditions on taste components in Fuding white tea infusions.

Science.gov (United States)

Zhang, Haihua; Li, Yulin; Lv, Yangjun; Jiang, Yulan; Pan, Junxian; Duan, Yuwei; Zhu, Yuejin; Zhang, Shikang

2017-07-01

White tea has received increasing attention of late as a result of its sweet taste and health benefits. During the brewing of white tea, many factors may affect the nutritional and sensory quality of the resulting infusions. The present study aimed to investigate the effect of various infusion conditions on the taste components of Fuding white tea, including infusion time, ratio of tea and water, number of brewing steps, and temperature. Brewing conditions had a strong effect on the taste compound profile and sensory characteristics. The catechin, caffeine, theanine and free amino acid contents generally increased with increasing infusion time and temperature. Conditions comprising an infusion time of 7 min, a brewing temperature of 100 °C, a tea and water ratio of 1:30 or 1:40, and a second brewing step, respectively, were shown to obtain the highest contents of most compounds. Regarding tea sensory evaluation, conditions comprising an infusion time of 3 min, a brewing temperature of 100 °C, a tea and water ratio of 1:50, and a first brewing step, resulted in the highest sensory score for comprehensive behavior of color, aroma and taste. The results of the present study reveal differences in the contents of various taste compounds, including catechins, caffeine, theanine and free amino acids, with respect to different brewing conditions, and sensory scores also varied with brewing conditions. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Overview of craft brewing specificities and potentially associated microbiota.

Science.gov (United States)

Rodhouse, Lindsey; Carbonero, Franck

2017-09-14

The brewing process differs slightly in craft breweries as compared to industrial breweries, as there are fewer control points. This affects the microbiota of the final product. Beer contains several antimicrobial properties that protect it from pathogens, such as low pH, low oxygen and high carbon dioxide content, and the addition of hops. However, these hurdles have limited power controlling spoilage organisms. Contamination by these organisms can originate in the raw materials, persist in the environment, and be introduced by using flavoring ingredients later in the process. Spoilage is a prominent issue in brewing, and can cause quality degradation resulting in consumer rejection and product waste. For example, lactic acid bacteria are predominately associated with producing a ropy texture and haze, along with producing diacetyl which gives the beer butter flavor notes. Other microorganisms may not affect flavor or aroma, but can retard fermentation by consuming nutrients needed by fermentation yeast. Quality control in craft breweries today relies on culturing methods to detect specific spoilage organisms. Using media can be beneficial for detecting the most common beer spoilers, such as Lactobacillus and Pediococci. However, these methods are time consuming with long incubation periods. Molecular methods such as community profiling or high throughput sequencing are better used for identifying entire populations of beer. These methods allow for detection, differentiation, and identification of taxa.

Vegemite Beer: yeast extract spreads as nutrient supplements to promote fermentation

Directory of Open Access Journals (Sweden)

Edward D. Kerr

2016-08-01

Full Text Available Vegemite is an iconic Australian food spread made from spent brewers’ yeast extract, which has been reported to be used as an ingredient in illegal home brewing. In this study, we tested the utility of Vegemite and the similar spread Marmite in promoting fermentation. We could not culture microorganisms from either Vegemite or Marmite, consistent with these food-grade spreads being essentially sterile. To test if the addition of Vegemite or Marmite could assist in fermentation when additional viable yeast was also present, solutions containing glucose and a range of concentrations of either Vegemite or Marmite were inoculated with brewers’ yeast. No fermentation occurred in any condition without addition of extra brewer’s yeast. Fermentation did not occur when yeast was inoculated into solutions containing only glucose, but progressed efficiently with when Vegemite or Marmite was also added. Gas Chromatography confirmed that ethanol was present at ∼3% v/v post-fermentation in all samples which contained glucose, Vegemite or Marmite, and brewers’ yeast. Trace amounts of methanol were also detected. Mass spectrometry proteomics identified abundant intracellular yeast proteins and barley proteins in Vegemite and Marmite, and abundant secreted yeast proteins from actively growing yeast in those samples to which extra brewers’ yeast had been added. We estimate that the real-world cost of home brewed “Vegemite Beer” would be very low. Our results show that Vegemite or other yeast extract spreads could provide cheap and readily available sources of nutrient supplementation to increase the efficiency of fermentation in home brewing or other settings.

The Brewing Process: Optimizing the Fermentation

Directory of Open Access Journals (Sweden)

Teodora Coldea

2014-11-01

Full Text Available Beer is a carbonated alcoholic beverage obtained by alcoholic fermentation of malt wort boiled with hops. Brown beer obtained at Beer Pilot Station of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca was the result of a recipe based on blond, caramel and black malt in different proportions, water, hops and yeast. This study aimed to monitorize the evolution of wort in primary and secondary alcoholic fermentation in order to optimize the process. Two wort batches were assambled in order to increase the brewing yeast fermentation performance. The primary fermentation was 14 days, followed by another 14 days of secondary fermentation (maturation. The must fermentation monitoring was done by the automatic FermentoStar analyzer. The whole fermentation process was monitorized (temperature, pH, alcohol concentration, apparent and total wort extract.

Breeding of a sake yeast mutant with enhanced ethyl caproate productivity in sake brewing using rice milled at a high polishing ratio.

Science.gov (United States)

Takahashi, Toshinari; Ohara, Yusuke; Sueno, Kazuo

2017-06-01

Sake yeast produces a fruity flavor known as ginjo-ko-which is mainly attributable to ethyl caproate and isoamyl acetate-during fermentation in sake brewing. The production of these flavor components is inhibited by unsaturated fatty acids derived from the outer layer of rice as raw material. We isolated three mutants (hec2, hec3, and hec6) with enhanced ethyl caproate productivity in sake brewing using rice milled at a high polishing ratio from a cerulenin-resistant mutant derived from the hia1 strain, which shows enhanced isoamyl acetate productivity. The hec2 mutant had the homozygous FAS2 mutation Gly1250Ser, which is known to confer high ethyl caproate productivity. When the homozygous FAS2 mutation Gly1250Ser was introduced into strain hia1, ethyl caproate productivity was increased but neither this nor intracellular caproic acid content approached the levels observed in the hec2 mutant, indicating that a novel mutation was responsible for the high ethyl caproate productivity. We also found that the expression of EEB1 encoding acyl-coenzyme A:ethanol O-acyltransferase (AEATase) and enzymatic activity were increased in the hec2 mutant. These results suggest that the upregulation of EEB1 expression and AEATase activity may also have contributed to the enhancement of ethyl caproate synthesis from ethanol and caproyl-CoA. Our findings are useful for the brewing of sake with improved flavor due to high levels of isoamyl acetate and ethyl caproate. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Physiological characterization of brewer's yeast in high-gravity beer fermentations with glucose or maltose syrups as adjuncts

DEFF Research Database (Denmark)

Piddocke, Maya Petrova; kreisz, Stefan; Heldt-Hansen, Hans Peter

2009-01-01

High-gravity brewing, which can decrease production costs by increasing brewery yields, has become an attractive alternative to traditional brewing methods. However, as higher sugar concentration is required, the yeast is exposed to various stresses during fermentation. We evaluated the influence...... of high-gravity brewing on the fermentation performance of the brewer’s yeast under model brewing conditions. The lager brewer’s strain Weihenstephan 34/70 strain was characterized at three different gravities by adding either glucose or maltose syrups to the basic wort. We observed that increased gravity...... resulted in more balanced fermentation performance in terms of higher cell numbers, respectively, higher wort fermentability and a more favorable flavor profile of the final beer. Our study underlines the effects of the various stress factors on brewer’s yeast metabolism and the influence of the type...

Brewing Beer in the Laboratory: Grain Amylases and Yeast's Sweet Tooth

Science.gov (United States)

Gillespie, Blake; Deutschman, William A.

2010-01-01

Brewing beer provides a straightforward and robust laboratory counterpart to classroom discussions of fermentation, a staple of the biochemistry curriculum. An exercise is described that provides several connections between lecture and laboratory content. Students first extract fermentable carbohydrates from whole grains, then ferment these with…

Triacetic acid lactone production in industrial Saccharomyces yeast strains

Science.gov (United States)

Triacetic acid lactone (TAL) is a potential platform chemical that can be produced in yeast. To evaluate the potential for industrial yeast strains to produce TAL, the g2ps1 gene encoding 2-pyrone synthase was transformed into thirteen industrial yeast strains of varied genetic background. TAL produ...

Differences between flocculating yeast and regular industrial yeast in transcription and metabolite profiling during ethanol fermentation

Directory of Open Access Journals (Sweden)

Lili Li

2017-03-01

Full Text Available Objectives: To improve ethanolic fermentation performance of self-flocculating yeast, difference between a flocculating yeast strain and a regular industrial yeast strain was analyzed by transcriptional and metabolic approaches. Results: The number of down-regulated (industrial yeast YIC10 vs. flocculating yeast GIM2.71 and up-regulated genes were 4503 and 228, respectively. It is the economic regulation for YIC10 that non-essential genes were down-regulated, and cells put more “energy” into growth and ethanol production. Hexose transport and phosphorylation were not the limiting-steps in ethanol fermentation for GIM2.71 compared to YIC10, whereas the reaction of 1,3-disphosphoglycerate to 3-phosphoglycerate, the decarboxylation of pyruvate to acetaldehyde and its subsequent reduction to ethanol were the most limiting steps. GIM2.71 had stronger stress response than non-flocculating yeast and much more carbohydrate was distributed to other bypass, such as glycerol, acetate and trehalose synthesis. Conclusions: Differences between flocculating yeast and regular industrial yeast in transcription and metabolite profiling will provide clues for improving the fermentation performance of GIM2.71.

Conversion of defective molasses into alcohol and yeasts

Energy Technology Data Exchange (ETDEWEB)

Luchev, S.

1966-01-01

The addition of small quantities (0.05 to 0.75%) of dried malt roots, green malt roots, green malt, yeast hydrolyzate, corn extraction, and tomato juice improved the quality and accelerated the brewing process in defective molasses. Dried malt roots and yeast hydrolyzate were the least expensive preparations.

Saccharomyces pastorianus: genomic insights inspiring innovation for industry.

Science.gov (United States)

Gibson, Brian; Liti, Gianni

2015-01-01

A combination of biological and non-biological factors has led to the interspecific hybrid yeast species Saccharomyces pastorianus becoming one of the world's most important industrial organisms. This yeast is used in the production of lager-style beers, the fermentation of which requires very low temperatures compared to other industrial fermentation processes. This group of organisms has benefited from both the whole-genome duplication in its ancestral lineage and the subsequent hybridization event between S. cerevisiae and S. eubayanus, resulting in strong fermentative ability. The hybrid has key traits, such as cold tolerance and good maltose- and maltotriose-utilizing ability, inherited either from the parental species or originating from genetic interactions between the parent genomes. Instability in the nascent allopolyploid hybrid genome may have contributed to rapid evolution of the yeast to tolerate conditions prevalent in the brewing environment. The recent discovery of S. eubayanus has provided new insights into the evolutionary history of S. pastorianus and may offer new opportunities for generating novel industrially-beneficial lager yeast strains. Copyright © 2014 John Wiley & Sons, Ltd.

Phenotypic evaluation and characterization of 21 industrial Saccharomyces cerevisiae yeast strains.

Science.gov (United States)

Kong, In Iok; Turner, Timothy Lee; Kim, Heejin; Kim, Soo Rin; Jin, Yong-Su

2018-02-01

Microorganisms have been studied and used extensively to produce value-added fuels and chemicals. Yeasts, specifically Saccharomyces cerevisiae, receive industrial attention because of their well-known ability to ferment glucose and produce ethanol. Thousands of natural or genetically modified S. cerevisiae have been found in industrial environments for various purposes. These industrial strains are isolated from industrial fermentation sites, and they are considered as potential host strains for superior fermentation processes. In many cases, industrial yeast strains have higher thermotolerance, increased resistances towards fermentation inhibitors and increased glucose fermentation rates under anaerobic conditions when compared with laboratory yeast strains. Despite the advantages of industrial strains, they are often not well characterized. Through screening and phenotypic characterization of commercially available industrial yeast strains, industrial fermentation processes requiring specific environmental conditions may be able to select an ideal starting yeast strain to be further engineered. Here, we have characterized and compared 21 industrial S. cerevisiae strains under multiple conditions, including their tolerance to varying pH conditions, resistance to fermentation inhibitors, sporulation efficiency and ability to ferment lignocellulosic sugars. These data may be useful for the selection of a parental strain for specific biotechnological applications of engineered yeast. © FEMS 2018. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Industrial brewing yeast engineered for the production of primary flavor determinants in hopped beer.

Science.gov (United States)

Denby, Charles M; Li, Rachel A; Vu, Van T; Costello, Zak; Lin, Weiyin; Chan, Leanne Jade G; Williams, Joseph; Donaldson, Bryan; Bamforth, Charles W; Petzold, Christopher J; Scheller, Henrik V; Martin, Hector Garcia; Keasling, Jay D

2018-03-20

Flowers of the hop plant provide both bitterness and "hoppy" flavor to beer. Hops are, however, both a water and energy intensive crop and vary considerably in essential oil content, making it challenging to achieve a consistent hoppy taste in beer. Here, we report that brewer's yeast can be engineered to biosynthesize aromatic monoterpene molecules that impart hoppy flavor to beer by incorporating recombinant DNA derived from yeast, mint, and basil. Whereas metabolic engineering of biosynthetic pathways is commonly enlisted to maximize product titers, tuning expression of pathway enzymes to affect target production levels of multiple commercially important metabolites without major collateral metabolic changes represents a unique challenge. By applying state-of-the-art engineering techniques and a framework to guide iterative improvement, strains are generated with target performance characteristics. Beers produced using these strains are perceived as hoppier than traditionally hopped beers by a sensory panel in a double-blind tasting.

Conventional and Non-Conventional Yeasts in Beer Production

Directory of Open Access Journals (Sweden)

Angela Capece

2018-06-01

Full Text Available The quality of beer relies on the activity of fermenting yeasts, not only for their good fermentation yield-efficiency, but also for their influence on beer aroma, since most of the aromatic compounds are intermediate metabolites and by-products of yeast metabolism. Beer production is a traditional process, in which Saccharomyces is the sole microbial component, and any deviation is considered a flaw. However, nowadays the brewing sector is faced with an increasing demand for innovative products, and it is diffusing the use of uncharacterized autochthonous starter cultures, spontaneous fermentation, or non-Saccharomyces starters, which leads to the production of distinctive and unusual products. Attempts to obtain products with more complex sensory characteristics have led one to prospect for non-conventional yeasts, i.e., non-Saccharomyces yeasts. These generally are characterized by low fermentation yields and are more sensitive to ethanol stress, but they provide a distinctive aroma and flavor. Furthermore, non-conventional yeasts can be used for the production of low-alcohol/non-alcoholic and light beers. This review aims to present the main findings about the role of traditional and non-conventional yeasts in brewing, demonstrating the wide choice of available yeasts, which represents a new biotechnological approach with which to target the characteristics of beer and to produce different or even totally new beer styles.

Copy number variations of genes involved in stress responses reflect the redox state and DNA damage in brewing yeasts.

Science.gov (United States)

Adamczyk, Jagoda; Deregowska, Anna; Skoneczny, Marek; Skoneczna, Adrianna; Natkanska, Urszula; Kwiatkowska, Aleksandra; Rawska, Ewa; Potocki, Leszek; Kuna, Ewelina; Panek, Anita; Lewinska, Anna; Wnuk, Maciej

2016-09-01

The yeast strains of the Saccharomyces sensu stricto complex involved in beer production are a heterogeneous group whose genetic and genomic features are not adequately determined. Thus, the aim of the present study was to provide a genetic characterization of selected group of commercially available brewing yeasts both ale top-fermenting and lager bottom-fermenting strains. Molecular karyotyping revealed that the diversity of chromosome patterns and four strains with the most accented genetic variabilities were selected and subjected to genome-wide array-based comparative genomic hybridization (array-CGH) analysis. The differences in the gene copy number were found in five functional gene categories: (1) maltose metabolism and transport, (2) response to toxin, (3) siderophore transport, (4) cellular aldehyde metabolic process, and (5) L-iditol 2-dehydrogenase activity (p < 0.05). In the Saflager W-34/70 strain (Fermentis) with the most affected array-CGH profile, loss of aryl-alcohol dehydrogenase (AAD) gene dosage correlated with an imbalanced redox state, oxidative DNA damage and breaks, lower levels of nucleolar proteins Nop1 and Fob1, and diminished tolerance to fermentation-associated stress stimuli compared to other strains. We suggest that compromised stress response may not only promote oxidant-based changes in the nucleolus state that may affect fermentation performance but also provide novel directions for future strain improvement.

Brewing Science

Science.gov (United States)

Pelter, Michael

2006-01-01

Following the brewing process from grain to glass, this course uses the biological and chemical principles of brewing to teach science to the nonscience major. Discussion of the scientific aspects of malting, mashing, fermentation, and the making of different beer styles is complemented by laboratory exercises that use scientific methods to…

Taming wild yeast: potential of conventional and nonconventional yeasts in industrial fermentations.

Science.gov (United States)

Steensels, Jan; Verstrepen, Kevin J

2014-01-01

Yeasts are the main driving force behind several industrial food fermentation processes, including the production of beer, wine, sake, bread, and chocolate. Historically, these processes developed from uncontrolled, spontaneous fermentation reactions that rely on a complex mixture of microbes present in the environment. Because such spontaneous processes are generally inconsistent and inefficient and often lead to the formation of off-flavors, most of today's industrial production utilizes defined starter cultures, often consisting of a specific domesticated strain of Saccharomyces cerevisiae, S. bayanus, or S. pastorianus. Although this practice greatly improved process consistency, efficiency, and overall quality, it also limited the sensorial complexity of the end product. In this review, we discuss how Saccharomyces yeasts were domesticated to become the main workhorse of food fermentations, and we investigate the potential and selection of nonconventional yeasts that are often found in spontaneous fermentations, such as Brettanomyces, Hanseniaspora, and Pichia spp.

Improving industrial yeast strains: exploiting natural and artificial diversity

Science.gov (United States)

Steensels, Jan; Snoek, Tim; Meersman, Esther; Nicolino, Martina Picca; Voordeckers, Karin; Verstrepen, Kevin J

2014-01-01

Yeasts have been used for thousands of years to make fermented foods and beverages, such as beer, wine, sake, and bread. However, the choice for a particular yeast strain or species for a specific industrial application is often based on historical, rather than scientific grounds. Moreover, new biotechnological yeast applications, such as the production of second-generation biofuels, confront yeast with environments and challenges that differ from those encountered in traditional food fermentations. Together, this implies that there are interesting opportunities to isolate or generate yeast variants that perform better than the currently used strains. Here, we discuss the different strategies of strain selection and improvement available for both conventional and nonconventional yeasts. Exploiting the existing natural diversity and using techniques such as mutagenesis, protoplast fusion, breeding, genome shuffling and directed evolution to generate artificial diversity, or the use of genetic modification strategies to alter traits in a more targeted way, have led to the selection of superior industrial yeasts. Furthermore, recent technological advances allowed the development of high-throughput techniques, such as ‘global transcription machinery engineering’ (gTME), to induce genetic variation, providing a new source of yeast genetic diversity. PMID:24724938

Natural and modified promoters for tailored metabolic engineering of the yeast Saccharomyces cerevisiae

NARCIS (Netherlands)

Hubmann, Georg; Thevelein, Johan M; Nevoigt, Elke

2014-01-01

The ease of highly sophisticated genetic manipulations in the yeast Saccharomyces cerevisiae has initiated numerous initiatives towards development of metabolically engineered strains for novel applications beyond its traditional use in brewing, baking, and wine making. In fact, baker's yeast has

Industrial Relevance of Chromosomal Copy Number Variation in Saccharomyces Yeasts

Science.gov (United States)

Gorter de Vries, Arthur R.; Pronk, Jack T.

2017-01-01

ABSTRACT Chromosomal copy number variation (CCNV) plays a key role in evolution and health of eukaryotes. The unicellular yeast Saccharomyces cerevisiae is an important model for studying the generation, physiological impact, and evolutionary significance of CCNV. Fundamental studies of this yeast have contributed to an extensive set of methods for analyzing and introducing CCNV. Moreover, these studies provided insight into the balance between negative and positive impacts of CCNV in evolutionary contexts. A growing body of evidence indicates that CCNV not only frequently occurs in industrial strains of Saccharomyces yeasts but also is a key contributor to the diversity of industrially relevant traits. This notion is further supported by the frequent involvement of CCNV in industrially relevant traits acquired during evolutionary engineering. This review describes recent developments in genome sequencing and genome editing techniques and discusses how these offer opportunities to unravel contributions of CCNV in industrial Saccharomyces strains as well as to rationally engineer yeast chromosomal copy numbers and karyotypes. PMID:28341679

Improving industrial yeast strains: exploiting natural and artificial diversity.

Science.gov (United States)

Steensels, Jan; Snoek, Tim; Meersman, Esther; Picca Nicolino, Martina; Voordeckers, Karin; Verstrepen, Kevin J

2014-09-01

Yeasts have been used for thousands of years to make fermented foods and beverages, such as beer, wine, sake, and bread. However, the choice for a particular yeast strain or species for a specific industrial application is often based on historical, rather than scientific grounds. Moreover, new biotechnological yeast applications, such as the production of second-generation biofuels, confront yeast with environments and challenges that differ from those encountered in traditional food fermentations. Together, this implies that there are interesting opportunities to isolate or generate yeast variants that perform better than the currently used strains. Here, we discuss the different strategies of strain selection and improvement available for both conventional and nonconventional yeasts. Exploiting the existing natural diversity and using techniques such as mutagenesis, protoplast fusion, breeding, genome shuffling and directed evolution to generate artificial diversity, or the use of genetic modification strategies to alter traits in a more targeted way, have led to the selection of superior industrial yeasts. Furthermore, recent technological advances allowed the development of high-throughput techniques, such as 'global transcription machinery engineering' (gTME), to induce genetic variation, providing a new source of yeast genetic diversity. © 2014 The Authors. FEMS Microbiology Reviews published by John Wiley & Sons Ltd on behalf of Federation of European Microbiological Societies.

Biogas Production from Brewer’s Yeast Using an Anaerobic Sequencing Batch Reactor

Directory of Open Access Journals (Sweden)

Gregor Drago Zupančič

2017-01-01

Full Text Available Renewable energy sources are becoming increasingly important in the beverage and food industries. In the brewing industry, a significant percentage of the used raw materials finishes the process as secondary resource or waste. The research on the anaerobic digestion of brewer’s yeast has been scarce until recent years. One of the reasons for this is its use as a secondary resource in the food industry and as cattle feed. Additionally, market value of brewer’s yeast is higher than its energy value. Due to the increase of energy prices, brewer’s yeast has become of interest as energy substrate despite its difficult degradability in anaerobic conditions. The anaerobic co-digestion of brewer’s yeast and anaerobically treated brewery wastewater was studied using a pilot-scale anaerobic sequencing batch reactor (ASBR seeded with granular biomass. The experiments showed very good and stable operation with an organic loading rate of up to 8.0 kg/(m3·day, and with a maximum achieved organic loading rate of 13.6 kg/(m3·day in a single cycle. A specific biogas productivity of over 0.430 m3/kg of the total chemical oxygen demand (COD inserted, and total COD removal efficiencies of over 90 % were achieved. This study suggests that the brewer’s yeast can be successfully digested in an ASBR without adverse effects on the biogas production from brewer’s yeast/wastewater mixtures of up to 8 % (by volume. By using the brewer’s yeast in the ASBR process, the biogas production from brewery wastewater could be increased by 50 %.

Industrial Relevance of Chromosomal Copy Number Variation in Saccharomyces Yeasts.

Science.gov (United States)

Gorter de Vries, Arthur R; Pronk, Jack T; Daran, Jean-Marc G

2017-06-01

Chromosomal copy number variation (CCNV) plays a key role in evolution and health of eukaryotes. The unicellular yeast Saccharomyces cerevisiae is an important model for studying the generation, physiological impact, and evolutionary significance of CCNV. Fundamental studies of this yeast have contributed to an extensive set of methods for analyzing and introducing CCNV. Moreover, these studies provided insight into the balance between negative and positive impacts of CCNV in evolutionary contexts. A growing body of evidence indicates that CCNV not only frequently occurs in industrial strains of Saccharomyces yeasts but also is a key contributor to the diversity of industrially relevant traits. This notion is further supported by the frequent involvement of CCNV in industrially relevant traits acquired during evolutionary engineering. This review describes recent developments in genome sequencing and genome editing techniques and discusses how these offer opportunities to unravel contributions of CCNV in industrial Saccharomyce s strains as well as to rationally engineer yeast chromosomal copy numbers and karyotypes. Copyright © 2017 Gorter de Vries et al.

Effects of malting conditions on the amino acid compositions of final ...

African Journals Online (AJOL)

Barley has been widely used for the production of malt in the brewing industry. Malt was the main raw material indispensable for beer brewing. The fermentability of malt wort is dependent on an adequate supply of the essential nutrients required by yeast. The amino acid content is an important malt parameter to the yeast ...

Development of Industrial Yeast Platform Strains

DEFF Research Database (Denmark)

Bergdahl, Basti; Dato, Laura; Förster, Jochen

2014-01-01

Most of the current metabolic engineering projects are carried out using laboratory strains as the starting host. Although such strains are easily manipulated genetically, their robustness does not always meet the requirements set by industrial fermentation conditions. In such conditions, the cells...... screening of the 36 industrial and laboratory yeast strains. In addition, progress in the development of molecular biology methods for generating the new strains will be presented....

Effects of spent craft brewers’ yeast on fermentation and methane production by rumen microorganisms

Science.gov (United States)

Saccharomyces cerevisiae is a key component of beer brewing and a major by-product. The leftover, spent brewers’ yeast, from large breweries has been used for some time as a protein supplement in cattle, however the possible advantages of spent yeast from smaller craft breweries, containing much hig...

Enhancing adhesion of yeast brewery strains to chamotte carriers through aminosilane surface modification.

Science.gov (United States)

Berlowska, Joanna; Kregiel, Dorota; Ambroziak, Wojciech

2013-07-01

The adhesion of cells to solid supports is described as surface-dependent, being largely determined by the properties of the surface. In this study, ceramic surfaces modified using different organosilanes were tested for proadhesive properties using industrial brewery yeast strains in different physiological states. Eight brewing strains were tested: bottom-fermenting Saccharomyces pastorianus and top-fermenting Saccharomyces cerevisiae. To determine adhesion efficiency light microscopy, scanning electron microscopy and the fluorymetric method were used. Modification of chamotte carriers by 3-(3-anino-2-hydroxy-1-propoxy) propyldimethoxysilane and 3-(N, N-dimethyl-N-2-hydroxyethyl) ammonium propyldimethoxysilane groups increased their biomass load significantly.

Pollutant removal-oriented yeast biomass production from high-organic-strength industrial wastewater: A review

International Nuclear Information System (INIS)

Yang, Min; Zheng, Shaokui

2014-01-01

Microbial single-cell-protein (SCP) production from high-organic-strength industrial wastewaters is considered an attractive method for both wastewater purification and resource utilization. In the last two decades, pollutant removal-oriented yeast SCP production processes, i.e., yeast treatment processes, have attracted a great deal of attention from a variety of research groups worldwide. Different from conventional SCP production processes, yeast treatment processes are characterized by higher pollutant removal rates, lower production costs, highly adaptive yeast isolates from nature, no excess nutrient supplements, and are performed under non-sterile conditions. Furthermore, yeast treatment processes are similar to bacteria-dominated conventional activated sludge processes, which offer more choices for yeast SCP production and industrial wastewater treatment. This review discusses why highly adaptive yeast species isolated from nature are used in the yeast treatment process rather than commercial SCP producers. It also describes the application of yeast treatment processes for treating high-carboxyhydrate, oil-rich and high-salinity industrial wastewater, focusing primarily on high-strength biodegradable organic substances, which usually account for the major fraction of biochemical oxygen demand. Also discussed is the biodegradation of xenobiotics, such as color (including dye and pigment) and toxic substances (including phenols, chlorophenols, polycyclic aromatic hydrocarbons, etc.), present in industrial wastewater. Based on molecular information of yeast community structures and their regulation in yeast treatment systems, we also discuss how to maintain efficient yeast species in yeast biomass and how to control bacterial and mold proliferation in yeast treatment systems. - Highlights: • Pollutant removal-oriented yeast SCP production processes offer more choices. • Highly adaptive yeast isolates replace commercial SCP producers. • Yeasts degrade

A thermostable Gloeophyllum trabeum xylanase with potential for the brewing industry.

Science.gov (United States)

Wang, Xiaoyu; Luo, Huiying; Yu, Wangning; Ma, Rui; You, Shuai; Liu, Weina; Hou, Lingyu; Zheng, Fei; Xie, Xiangming; Yao, Bin

2016-05-15

A xylanase gene of glycoside hydrolase family 10, GtXyn10, was cloned from Gloeophyllum trabeum CBS 900.73 and expressed in Pichia pastoris GS115. Purified recombinant GtXyn10 exhibited significant activities to xylan (100.0%), lichenan (11.2%), glucan (15.2%) and p-nitrophenol-β-cellobiose (18.6%), demonstrated the maximum xylanase and glucanase activities at pH 4.5-5.0 and 75°C, retained stability over the pH range of 2.0-7.5 and at 70°C, and was resistant to pepsin and trypsin, most metal ions and SDS. Multiple sequence alignment and modeled-structure analysis identified a unique Gly48 in GtXyn10, and site-directed mutagenesis of Gly48 to Lys improved the temperature optimum up to 80°C. Under simulated mashing conditions, GtXyn10 (80U) reduced the mash viscosity by 12.8% and improved the filtration rate by 31.3%. All these properties above make GtXyn10 attractive for potential applications in the feed and brewing industries. Copyright © 2015 Elsevier Ltd. All rights reserved.

The ecology of insect-yeast relationships and its relevance to human industry.

Science.gov (United States)

Madden, Anne A; Epps, Mary Jane; Fukami, Tadashi; Irwin, Rebecca E; Sheppard, John; Sorger, D Magdalena; Dunn, Robert R

2018-03-28

Many species of yeast are integral to human society. They produce many of our foods, beverages and industrial chemicals, challenge us as pathogens, and provide models for the study of our own biology. However, few species are regularly studied and much of their ecology remains unclear, hindering the development of knowledge that is needed to improve the relationships between humans and yeasts. There is increasing evidence that insects are an essential component of ascomycetous yeast ecology. We propose a 'dispersal-encounter hypothesis' whereby yeasts are dispersed by insects between ephemeral, spatially disparate sugar resources, and insects, in turn, obtain the benefits of an honest signal from yeasts for the sugar resources. We review the relationship between yeasts and insects through three main examples: social wasps, social bees and beetles, with some additional examples from fruit flies. Ultimately, we suggest that over the next decades, consideration of these ecological and evolutionary relationships between insects and yeasts will allow prediction of where new yeast diversity is most likely to be discovered, particularly yeasts with traits of interest to human industry. © 2018 The Author(s).

Effects of Wastes from the Brewing Industry in Lightweight Aggregates Manufactured with Clay for Green Roofs

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Romina D. Farías

2017-05-01

Full Text Available This study investigates the effects of sieved wastes generated from the brewing industry on lightweight aggregates manufactured with clay. Sludge from a wastewater treatment plant, bagasse and diatomaceous earth were used to obtain the samples. These wastes are usually dumped in landfills, but the current increase in restrictions on dumping and interest in improving the environment make our proposal for gaining value from these wastes a significant contribution. Laboratory tests show that the new aggregate has low bulk density and increased water absorption and porosity. The thermographic camera results provide evidence that new aggregates have significant insulating properties and are suitable for use on green roofs.

Effects of Wastes from the Brewing Industry in Lightweight Aggregates Manufactured with Clay for Green Roofs

Science.gov (United States)

Farías, Romina D.; Martínez García, Carmen; Cotes Palomino, Teresa; Martínez Arellano, Myriam

2017-01-01

This study investigates the effects of sieved wastes generated from the brewing industry on lightweight aggregates manufactured with clay. Sludge from a wastewater treatment plant, bagasse and diatomaceous earth were used to obtain the samples. These wastes are usually dumped in landfills, but the current increase in restrictions on dumping and interest in improving the environment make our proposal for gaining value from these wastes a significant contribution. Laboratory tests show that the new aggregate has low bulk density and increased water absorption and porosity. The thermographic camera results provide evidence that new aggregates have significant insulating properties and are suitable for use on green roofs. PMID:28772892

Globalization of Brewing and Economies of Scale

DEFF Research Database (Denmark)

Madsen, Erik Strøjer; Wu, Yanqing

The globalization of the brewing industry after the turn of the century through a large wave of mergers and acquisitions has changed the structure of the world beer markets. The paper tracks the development in industry concentrations from 2002 to 2012 and points to high transportation costs...... for beers and economies of scale in advertising and sales efforts as the main factors behind the wave of cross-country mergers and acquisitions. Using firm-level data from the largest breweries, the estimations verify significant economies of scale in marketing and distribution costs. Based on information...

Characterization of volatile aroma compounds in different brewing barley cultivars.

Science.gov (United States)

Dong, Liang; Hou, Yingmin; Li, Feng; Piao, Yongzhe; Zhang, Xiao; Zhang, Xiaoyu; Li, Cheng; Zhao, Changxin

2015-03-30

Beer is a popular alcoholic malt beverage resulting from fermentation of the aqueous extract of malted barley with hops. The aroma of brewing barley impacts the flavor of beer indirectly, because some flavor compounds or their precursors in beer come from the barley. The objectives of this research were to study volatile profiles and to characterize odor-active compounds of brewing barley in order to determine the variability of the aroma composition among different brewing barley cultivars. Forty-one volatiles comprising aldehydes, ketones, alcohols, organic acids, aromatic compounds and furans were identified using solid phase microextraction combined with gas chromatography/mass spectrometry, among which aldehydes, alcohols and ketones were quantitatively in greatest abundance. Quantitative measurements performed by means of solvent extraction and calculation of odor activity values revealed that acetaldehyde, 2-methylpropanal, 3-methylbutanal, 2-methylbutanal, hexanal, heptanal, octanal, nonanal, 3-methyl-1-butanol, cyclopentanol, 2,3-butanedione, 2,3-pentanedione, 2-heptanone, acetic acid, ethyl acetate, 2-pentylfuran and benzeneacetaldehyde, whose concentrations exceeded their odor thresholds, could be considered as odor-active compounds of brewing barley. Principal component analysis was employed to evaluate the differences among cultivars. The results demonstrated that the volatile profile based on the concentrations of aroma compounds enabled good differentiation of most barley cultivars. © 2014 Society of Chemical Industry.

Population structure and reticulate evolution of Saccharomyces eubayanus and its lager-brewing hybrids.

Science.gov (United States)

Peris, David; Sylvester, Kayla; Libkind, Diego; Gonçalves, Paula; Sampaio, José Paulo; Alexander, William G; Hittinger, Chris Todd

2014-04-01

Reticulate evolution can be a major driver of diversification into new niches, especially in disturbed habitats and at the edges of ranges. Industrial fermentation strains of yeast provide a window into these processes, but progress has been hampered by a limited understanding of the natural diversity and distribution of Saccharomyces species and populations. For example, lager beer is brewed with Saccharomyces pastorianus, an alloploid hybrid of S. cerevisiae and S. eubayanus, a species only recently discovered in Patagonia, Argentina. Here, we report that genetically diverse strains of S. eubayanus are readily isolated from Patagonia, demonstrating that the species is well established there. Analyses of multilocus sequence data strongly suggest that there are two diverse and highly differentiated Patagonian populations. The low nucleotide diversity found in the S. eubayanus moiety of hybrid European brewing strains suggests that their alleles were drawn from a small subpopulation that is closely related to one of the Patagonian populations. For the first time, we also report the rare isolation of S. eubayanus outside Patagonia, in Wisconsin, USA. In contrast to the clear population differentiation in Patagonia, the North American strains represent a recent and possibly transient admixture of the two Patagonian populations. These complex and varied reticulation events are not adequately captured by conventional phylogenetic methods and required analyses of Bayesian concordance factors and phylogenetic networks to accurately summarize and interpret. These findings show how genetically diverse eukaryotic microbes can produce rare but economically important hybrids with low genetic diversity when they migrate from their natural ecological context. © 2014 John Wiley & Sons Ltd.

Revaluation of Waste Yeast from Beer Production

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Nicoleta Suruceanu

2013-11-01

Full Text Available Brewing yeast is an important waste product from beer production. The valorification of slurry yeast mainly consists of separation of vitamins and important nitrogen compounds. The hops compounds, one of the most important raw materials in beer technology are removed beforehand valorification. The prenylflavonoids compounds from hops are important bioactive compounds that can be revaluation with proper technology. Revaluation of prenylflavonoids from waste yeast into dietary supplement, identification and quantification of xanthohumol by HPLC method. Waste yeast from brewery pilot plant of USAMV Cluj Napoca it was dried by atomization and the powder was analyzed on xanthohumol content by HPLC method. For quantification a calibration curve it was used. The process of drying by atomisation lead to a powder product. It was used malt dextrin powder for stabilisation. The final product it was encapsulated. The xanthohumol content of powdered yeast it was 1.94 µg/ml. In conclusion the slurry yeast from beer production it is an important source of prenylflavonoids compounds.

The Benefits and Risks of Consuming Brewed Tea: Beware of Toxic Element Contamination

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Gerry Schwalfenberg

2013-01-01

Full Text Available Background. Increasing concern is evident about contamination of foodstuffs and natural health products. Methods. Common off-the-shelf varieties of black, green, white, and oolong teas sold in tea bags were used for analysis in this study. Toxic element testing was performed on 30 different teas by analyzing (i tea leaves, (ii tea steeped for 3-4 minutes, and (iii tea steeped for 15–17 minutes. Results were compared to existing preferred endpoints. Results. All brewed teas contained lead with 73% of teas brewed for 3 minutes and 83% brewed for 15 minutes having lead levels considered unsafe for consumption during pregnancy and lactation. Aluminum levels were above recommended guidelines in 20% of brewed teas. No mercury was found at detectable levels in any brewed tea samples. Teas contained several beneficial elements such as magnesium, calcium, potassium, and phosphorus. Of trace minerals, only manganese levels were found to be excessive in some black teas. Conclusions. Toxic contamination by heavy metals was found in most of the teas sampled. Some tea samples are considered unsafe. There are no existing guidelines for routine testing or reporting of toxicant levels in “naturally” occurring products. Public health warnings or industry regulation might be indicated to protect consumer safety.

Effect of brewing technique and particle size of the ground coffee on sensory profiling of brewed Dampit robusta coffee

Science.gov (United States)

Fibrianto, K.; Febryana, Y. R.; Wulandari, E. S.

2018-03-01

This study aimed to assess the effect of different brewing techniques with the use of appropriate particle size standard of Apresiocoffee cafe (Category 1) compared to the difference brewing techniques with the use of the same particle size (coarse) (Category 2) of the sensory attributes Dampit robusta coffee. Rate-All-That-Apply (RATA) method was applied in this study, and the data was analysed by ANOVA General Linier Model (GLM) on Minitab-16. The influence of brewing techniques (tubruk, French-press, drips, syphon) and type of particle size ground coffee (fine, medium, coarse) were sensorially observed. The result showed that only two attributes, including bitter taste, and astringent/rough-mouth-feel were affected by brewing techniques (p-value <0.05) as observed for brewed coarse coffee powder.

1H NMR-based metabolic profiling for evaluating poppy seed rancidity and brewing.

Science.gov (United States)

Jawień, Ewa; Ząbek, Adam; Deja, Stanisław; Łukaszewicz, Marcin; Młynarz, Piotr

2015-12-01

Poppy seeds are widely used in household and commercial confectionery. The aim of this study was to demonstrate the application of metabolic profiling for industrial monitoring of the molecular changes which occur during minced poppy seed rancidity and brewing processes performed on raw seeds. Both forms of poppy seeds were obtained from a confectionery company. Proton nuclear magnetic resonance (1H NMR) was applied as the analytical method of choice together with multivariate statistical data analysis. Metabolic fingerprinting was applied as a bioprocess control tool to monitor rancidity with the trajectory of change and brewing progressions. Low molecular weight compounds were found to be statistically significant biomarkers of these bioprocesses. Changes in concentrations of chemical compounds were explained relative to the biochemical processes and external conditions. The obtained results provide valuable and comprehensive information to gain a better understanding of the biology of rancidity and brewing processes, while demonstrating the potential for applying NMR spectroscopy combined with multivariate data analysis tools for quality control in food industries involved in the processing of oilseeds. This precious and versatile information gives a better understanding of the biology of these processes.

Lignocellulosic ethanol production by starch-base industrial yeast under PEG detoxification

Science.gov (United States)

Liu, Xiumei; Xu, Wenjuan; Mao, Liaoyuan; Zhang, Chao; Yan, Peifang; Xu, Zhanwei; Zhang, Z. Conrad

2016-02-01

Cellulosic ethanol production from lignocellulosic biomass offers a sustainable solution for transition from fossil based fuels to renewable alternatives. However, a few long-standing technical challenges remain to be addressed in the development of an economically viable fermentation process from lignocellulose. Such challenges include the needs to improve yeast tolerance to toxic inhibitory compounds and to achieve high fermentation efficiency with minimum detoxification steps after a simple biomass pretreatment. Here we report an in-situ detoxification strategy by PEG exo-protection of an industrial dry yeast (starch-base). The exo-protected yeast cells displayed remarkably boosted vitality with high tolerance to toxic inhibitory compounds, and with largely improved ethanol productivity from crude hydrolysate derived from a pretreated lignocellulose. The PEG chemical exo-protection makes the industrial S. cerevisiae yeast directly applicable for the production of cellulosic ethanol with substantially improved productivity and yield, without of the need to use genetically modified microorganisms.

Engineering industrial yeast for renewable advanced biofuels applications

Science.gov (United States)

The industrial yeast Saccharomyces cerevisiae is a candidate for the next-generation biocatalyst development due to its unique genomic background and robust performance in fermentation-based production. In order to meet challenges of renewable and sustainable advanced biofuels conversion including ...

Sustainable operations management and benchmarking in brewing: A factor weighting approach

Directory of Open Access Journals (Sweden)

Daniel P. Bumblauskas

2017-06-01

Full Text Available The brewing industry has been moving towards more efficient use of energy, water reuse and stewardship, and the tracking of greenhouse gas (GHG emissions to better manage environmental and social responsibility. Commercial breweries use a great deal of water and energy to convert one gallon (liter of water into one gallon (liter of beer. An analysis was conducted on sustainable operations and supply chain management at various United States and international breweries, specifically Europe, to benchmark brewery performance and establish common metrics for sustainability in the beer supply chain. The primary research questions explored in this article are whether water reclamation and GHG emissions can be properly monitored and measured and if processes can be created to help control waste (lean and emissions. Additional questions include how we can use operations management strategies and techniques such as the Factor-Weighted Method (FWM in industries such as brewing to develop sustainability scorecards.

Research progress on the brewing techniques of new-type rice wine.

Science.gov (United States)

Jiao, Aiquan; Xu, Xueming; Jin, Zhengyu

2017-01-15

As a traditional alcoholic beverage, Chinese rice wine (CRW) with high nutritional value and unique flavor has been popular in China for thousands of years. Although traditional production methods had been used without change for centuries, numerous technological innovations in the last decades have greatly impacted on the CRW industry. However, reviews related to the technology research progress in this field are relatively few. This article aimed at providing a brief summary of the recent developments in the new brewing technologies for making CRW. Based on the comparison between the conventional methods and the innovative technologies of CRW brewing, three principal aspects were summarized and sorted, including the innovation of raw material pretreatment, the optimization of fermentation and the reform of sterilization technology. Furthermore, by comparing the advantages and disadvantages of these methods, various issues are addressed related to the prospect of the CRW industry. Copyright © 2016 Elsevier Ltd. All rights reserved.

High levels of melatonin generated during the brewing process.

Science.gov (United States)

Garcia-Moreno, H; Calvo, J R; Maldonado, M D

2013-08-01

Beer is a beverage consumed worldwide. It is produced from cereals (barley or wheat) and contains a wide array of bioactive phytochemicals and nutraceutical compounds. Specifically, high melatonin concentrations have been found in beer. Beers with high alcohol content are those that present the greatest concentrations of melatonin and vice versa. In this study, gel filtration chromatography and ELISA were combined for melatonin determination. We brewed beer to determine, for the first time, the beer production steps in which melatonin appears. We conclude that the barley, which is malted and ground in the early process, and the yeast, during the second fermentation, are the largest contributors to the enrichment of the beer with melatonin. © 2012 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

An investigation of how the Australian brewing industry influence consumers on Twitter

Directory of Open Access Journals (Sweden)

Torgeir Aleti

2016-08-01

Full Text Available In this paper we develop and test hypotheses around organisations’ behaviour on social media and its effect on consumers’ responses. We draw on the notion of the market maven to underpin the research and suggest that organisations on social media need to focus on acting in a maven-like manner in order to influence audiences in Twitter. We collected data from the Twitter accounts of the entire brewing industry in Australia, analysing organisational postings and their impact on influence (follower numbers, retweets of their respective Twitter accounts. In particular, we look at message formulation and language, native platform behaviour, reciprocity and persistency variables. Findings suggest that establishing a larger follower base requires an interactive, one-to-one and reciprocal approach. In order to influence audiences to retweet organisations need to speak the ‘native platform language’ and employ a soft-sell strategy. Maven-like behaviour tends to reside in the small independent craft breweries. We offer the conclusion that these craft breweries have realised that, on social media, a different approach to marketing is required: the organisations must act in a maven-like manner.

Engineered CRISPR/Cas9 system for multiplex genome engineering of polyploid industrial yeast strains.

Science.gov (United States)

Lian, Jiazhang; Bao, Zehua; Hu, Sumeng; Zhao, Huimin

2018-06-01

The CRISPR/Cas9 system has been widely used for multiplex genome engineering of Saccharomyces cerevisiae. However, its application in manipulating industrial yeast strains is less successful, probably due to the genome complexity and low copy numbers of gRNA expression plasmids. Here we developed an efficient CRISPR/Cas9 system for industrial yeast strain engineering by using our previously engineered plasmids with increased copy numbers. Four genes in both a diploid strain (Ethanol Red, 8 alleles in total) and a triploid strain (ATCC 4124, 12 alleles in total) were knocked out in a single step with 100% efficiency. This system was used to construct xylose-fermenting, lactate-producing industrial yeast strains, in which ALD6, PHO13, LEU2, and URA3 were disrupted in a single step followed by the introduction of a xylose utilization pathway and a lactate biosynthetic pathway on auxotrophic marker plasmids. The optimized CRISPR/Cas9 system provides a powerful tool for the development of industrial yeast based microbial cell factories. © 2018 Wiley Periodicals, Inc.

The use of home brew in Pacific Islands countries and territories.

Science.gov (United States)

Nosa, Vili; Duffy, Shavonne; Singh, Debbie; Lavelio, Save; Amber, Uma; Homasi-Paelate, Avanoa; Alfred, Julia

2018-01-01

This review examines what is known about the production and use of home brew in the Pacific Islands countries and territories. Data collection involved interviews of 78 men and women from the Marshall Islands, Papua New Guinea, Toga, and Tuvalu. The interviews were conducted in 2013 by local interviewers. The questions fell into four key areas: people's history of home-brew consumption, the reasons for home-brew use, the effects of home brew, and people's perceptions about home brew. An open ethnographic approach revealed that males are the main consumers of home brew, that home brew is consumed in private venues by those with low socioeconomic status, and that there are positive and negative outcomes associated with the use of home brew. Finally, policy implications of the findings are included in this article.

Sensory and Instrumental Flavor Changes in Green Tea Brewed Multiple Times

Science.gov (United States)

Lee, Jeehyun; Chambers, Delores; Chambers, Edgar

2013-01-01

Green teas in leaf form are brewed multiple times, a common selling point. However, the flavor changes, both sensory and volatile compounds, of green teas that have been brewed multiple times are unknown. The objectives of this study were to determine how the aroma and flavor of green teas change as they are brewed multiple times, to determine if a relationship exists between green tea flavors and green tea volatile compounds, and to suggest the number of times that green tea leaves can be brewed. The first and second brews of the green tea samples provided similar flavor intensities. The third and fourth brews provided milder flavors and lower bitterness and astringency when measured using descriptive sensory analysis. In the brewed liquor of green tea mostly linalool, nonanal, geraniol, jasmone, and β-ionone volatile compounds were present at low levels (using gas chromatography-mass spectrometry). The geraniol, linalool, and linalool oxide compounds in green tea may contribute to the floral/perfumy flavor. Green teas in leaf form may be brewed up to four times: the first two brews providing stronger flavor, bitterness, and astringency whereas the third and fourth brews will provide milder flavor, bitterness, and astringency. PMID:28239138

Toward a New Brewing Control Chart for the 21st Century.

Science.gov (United States)

Melrose, John; Roman-Corrochano, Borja; Montoya-Guerra, Marcela; Bakalis, Serafim

2018-04-23

This paper describes new results from a base model of brewing from a bed of packed coffee grains. The model solves for the diffusion of soluble species out of a distribution of particles into the flow through the bed pore space. It requires a limited set of input parameters. It gives a simple picture of the basic physics of coffee brewing and sets out a set of reduced variables for this process. The importance of bed extraction efficiency is elucidated. A coffee brewing control chart has been widely used to describe the region of ideal coffee brewing for some 50 years. A new chart is needed, however, one that connects actual brewing conditions (weight, flow rate, brew time, grind, etc.) to the yield and strength of brews. The paper shows a new approach to brewing control charts, including brew time and bed extraction efficiency as control parameters. Using the base model, an example chart will be given for a particular grind ratio of coarse to fine particles, and an "espresso regime" will be picked out. From such a chart yield, volume and strength of a brew can be read off at will.

Combining unmalted barley and pearling gives good quality brewing

NARCIS (Netherlands)

Donkelaar, van Laura H.G.; Hageman, Jos A.; Oguz, Serhat; Noordman, Tom R.; Boom, Remko M.; Goot, van der Atze Jan

2016-01-01

Brewing with unmalted barley can reduce the use of raw materials, thereby increasing the efficiency of the brewing process. However, unmalted barley contains several undesired components for brewing and has a low enzymatic activity. Pearling, an abrasive milling method, has been proposed as a

Analysis of the constitution of the beer yeast genome by PCR, sequencing and subtelomeric sequence hybridization

Czech Academy of Sciences Publication Activity Database

Casaregola, S.; Nguyen, H. V.; Lapathitis, G.; Kotyk, Arnošt; Gaillardin, C.

2001-01-01

Roč. 51, Pt. 4 (2001), s. 1607-1618 ISSN 1466-5026 Institutional research plan: CEZ:AV0Z5011922 Keywords : brewing yeast * Saccharomyces pastorianus * Saccharomyces bayanus Subject RIV: EE - Microbiology, Virology Impact factor: 2.004, year: 2001

Co-production of bioethanol and probiotic yeast biomass from agricultural feedstock: application of the rural biorefinery concept.

Science.gov (United States)

Hull, Claire M; Loveridge, E Joel; Donnison, Iain S; Kelly, Diane E; Kelly, Steven L

2014-01-01

Microbial biotechnology and biotransformations promise to diversify the scope of the biorefinery approach for the production of high-value products and biofuels from industrial, rural and municipal waste feedstocks. In addition to bio-based chemicals and metabolites, microbial biomass itself constitutes an obvious but overlooked by-product of existing biofermentation systems which warrants fuller attention. The probiotic yeast Saccharomyces boulardii is used to treat gastrointestinal disorders and marketed as a human health supplement. Despite its relatedness to S. cerevisiae that is employed widely in biotechnology, food and biofuel industries, the alternative applications of S. boulardii are not well studied. Using a biorefinery approach, we compared the bioethanol and biomass yields attainable from agriculturally-sourced grass juice using probiotic S. boulardii (strain MYA-769) and a commercial S. cerevisiae brewing strain (Turbo yeast). Maximum product yields for MYA-769 (39.18 [±2.42] mg ethanol mL(-1) and 4.96 [±0.15] g dry weight L(-1)) compared closely to those of Turbo (37.43 [±1.99] mg mL(-1) and 4.78 [±0.10] g L(-1), respectively). Co-production, marketing and/or on-site utilisation of probiotic yeast biomass as a direct-fed microbial to improve livestock health represents a novel and viable prospect for rural biorefineries. Given emergent evidence to suggest that dietary yeast supplementations might also mitigate ruminant enteric methane emissions, the administration of probiotic yeast biomass could also offer an economically feasible way of reducing atmospheric CH4.

Yeast production from cellulase hydrolyzed furfural industrial waste. II. Conditions for the cultivation of yeast

Energy Technology Data Exchange (ETDEWEB)

1977-01-01

Three yeast strains, Candida AS 2-121, C. utilis AS 2-1180, and C. tropicalis AS 2-637 were selected as being capable of growing on cellulase-hydrolyzed furfural industrial waste. Cell mass yields with respect to C source were approximately 50%. Fermentation conditions are given.

Multiplex engineering of industrial yeast genomes using CRISPRm.

Science.gov (United States)

Ryan, Owen W; Cate, Jamie H D

2014-01-01

Global demand has driven the use of industrial strains of the yeast Saccharomyces cerevisiae for large-scale production of biofuels and renewable chemicals. However, the genetic basis of desired domestication traits is poorly understood because robust genetic tools do not exist for industrial hosts. We present an efficient, marker-free, high-throughput, and multiplexed genome editing platform for industrial strains of S. cerevisiae that uses plasmid-based expression of the CRISPR/Cas9 endonuclease and multiple ribozyme-protected single guide RNAs. With this multiplex CRISPR (CRISPRm) system, it is possible to integrate DNA libraries into the chromosome for evolution experiments, and to engineer multiple loci simultaneously. The CRISPRm tools should therefore find use in many higher-order synthetic biology applications to accelerate improvements in industrial microorganisms.

Spent yeast as natural source of functional food additives

Science.gov (United States)

Rakowska, Rita; Sadowska, Anna; Dybkowska, Ewa; Świderski, Franciszek

Spent yeasts are by-products arising from beer and wine production which over many years have been chiefly used as feed additives for livestock. They contain many valuable and bioactive substances which has thereby generated much interest in their exploitation. Up till now, the main products obtained from beer-brewing yeasts are β-glucans and yeast extracts. Other like foodstuffs include dried brewer’s yeast, where this is dried and the bitterness removed to be fit for human consumption as well as mannan-oligosaccharides hitherto used in the feed industry. β-glucans constitute the building blocks of yeast cell walls and can thus be used in human nutrition as dietary supplements or serving as food additives in functional foods. β-glucans products obtained via post-fermentation of beer also exhibit a high and multi-faceted biological activity where they improve the blood’s lipid profile, enhance immunological status and have both prebiotic and anti-oxidant properties. Yeast extracts are currently being used more and more to enhance flavour in foodstuffs, particularly for meat and its products. Depending on how autolysis is carried out, it is possible to design extracts of various meat flavours characteristic of specific meats. Many different flavour profiles can be created which may be additionally increased in combination with vegetable extracts. Within the food market, yeast extracts can appear in various guises such as liquids, pastes or powders. They all contain significant amounts of glutamic acid, 5’-GMP and 5’-IMP nucleotides together with various amino acids and peptides that act synergistically for enhancing the flavour of foodstuff products. Recent studies have demonstrated additional benefits of yeast extracts as valuable sources of amino acids and peptides which can be used in functional foods and dietary supplements. These products possess GRAS status (Generally Recognised As Safe) which thereby also adds further as to why they should be used

Engineering tolerance to industrially relevant stress factors in yeast cell factories.

Science.gov (United States)

Deparis, Quinten; Claes, Arne; Foulquié-Moreno, Maria R; Thevelein, Johan M

2017-06-01

The main focus in development of yeast cell factories has generally been on establishing optimal activity of heterologous pathways and further metabolic engineering of the host strain to maximize product yield and titer. Adequate stress tolerance of the host strain has turned out to be another major challenge for obtaining economically viable performance in industrial production. Although general robustness is a universal requirement for industrial microorganisms, production of novel compounds using artificial metabolic pathways presents additional challenges. Many of the bio-based compounds desirable for production by cell factories are highly toxic to the host cells in the titers required for economic viability. Artificial metabolic pathways also turn out to be much more sensitive to stress factors than endogenous pathways, likely because regulation of the latter has been optimized in evolution in myriads of environmental conditions. We discuss different environmental and metabolic stress factors with high relevance for industrial utilization of yeast cell factories and the experimental approaches used to engineer higher stress tolerance. Improving stress tolerance in a predictable manner in yeast cell factories should facilitate their widespread utilization in the bio-based economy and extend the range of products successfully produced in large scale in a sustainable and economically profitable way. © FEMS 2017.

Engineering tolerance to industrially relevant stress factors in yeast cell factories

Science.gov (United States)

Deparis, Quinten; Claes, Arne; Foulquié-Moreno, Maria R.

2017-01-01

Abstract The main focus in development of yeast cell factories has generally been on establishing optimal activity of heterologous pathways and further metabolic engineering of the host strain to maximize product yield and titer. Adequate stress tolerance of the host strain has turned out to be another major challenge for obtaining economically viable performance in industrial production. Although general robustness is a universal requirement for industrial microorganisms, production of novel compounds using artificial metabolic pathways presents additional challenges. Many of the bio-based compounds desirable for production by cell factories are highly toxic to the host cells in the titers required for economic viability. Artificial metabolic pathways also turn out to be much more sensitive to stress factors than endogenous pathways, likely because regulation of the latter has been optimized in evolution in myriads of environmental conditions. We discuss different environmental and metabolic stress factors with high relevance for industrial utilization of yeast cell factories and the experimental approaches used to engineer higher stress tolerance. Improving stress tolerance in a predictable manner in yeast cell factories should facilitate their widespread utilization in the bio-based economy and extend the range of products successfully produced in large scale in a sustainable and economically profitable way. PMID:28586408

The use of enzymes for beer brewing

NARCIS (Netherlands)

Donkelaar, van Laura H.G.; Mostert, Joost; Zisopoulos, Filippos K.; Boom, Remko M.; Goot, van der Atze Jan

2016-01-01

The exergetic performance of beer produced by the conventional malting and brewing process is compared with that of beer produced using an enzyme-assisted process. The aim is to estimate if the use of an exogenous enzyme formulation reduces the environmental impact of the overall brewing process.

Nanolaser Spectroscopy of Genetically Engineered Yeast: New Tool for a Better Brew?

Science.gov (United States)

Gourley, Paul L.; Hendricks, Judy K.; Naviaux, Robert K.; Yaffe, Michael P.

2006-03-01

A basic function of the cell membrane is to selectively uptake ions or molecules from its environment to concentrate them into the interior. This concentration difference results in an osmostic pressure difference across the membrane. Ultimately, this pressure and its fluctuation from cell to cell will be limited by the availability and fluctuations of the solute concentrations in solution, the extent of inter-cell communication, and the state of respiring intracellular mitochondria that fuel the process. To measure these fluctuations, we have employed a high-speed nanolaser technique that samples the osmotic pressure in individual yeast cells and isolated mitochondria. We analyzed 2 yeast cell strains, normal baker’s yeast and a genetically-altered version, that differ only by the presence of mitochondrial DNA. The absence of mitochondrial DNA results in the complete loss of all the mtDNA-encoded proteins and RNAs, and loss of the pigmented, heme-containing cytochromes. These cells have mitochondria, but the mitochondria lack most normal respiratory chain complexes. The frequency distributions in the nanolaser spectra produced by wild-type and modified cells and mitochondria show a striking shift from Gaussian to Poissonian distributions, revealing a powerful novel method for studying statistical physics of yeast.

Non-Genetic Engineering Approaches for Isolating and Generating Novel Yeasts for Industrial Applications

Science.gov (United States)

Chambers, P. J.; Bellon, J. R.; Schmidt, S. A.; Varela, C.; Pretorius, I. S.

Generating novel yeast strains for industrial applications should be quite straightforward; after all, research into the genetics, biochemistry and physiology of Baker's Yeast, Saccharomyces cerevisiae, has paved the way for many advances in the modern biological sciences. We probably know more about this humble eukaryote than any other, and it is the most tractable of organisms for manipulation using modern genetic engineering approaches. In many countries, however, there are restrictions on the use of genetically-modified organisms (GMOs), particularly in foods and beverages, and the level of consumer acceptance of GMOs is, at best, variable. Thus, many researchers working with industrial yeasts use genetic engineering techniques primarily as research tools, and strain development continues to rely on non-GM technologies. This chapter explores the non-GM tools and strategies available to such researchers.

Adaptive evolution of the lager brewing yeast Saccharomyces pastorianus for improved growth under hyperosmotic conditions and its influence on fermentation performance.

Science.gov (United States)

Ekberg, Jukka; Rautio, Jari; Mattinen, Laura; Vidgren, Virve; Londesborough, John; Gibson, Brian R

2013-05-01

An adaptive evolution method to obtain stable Saccharomyces pastorianus brewing yeast variants with improved fermentation capacity is described. The procedure involved selection for rapid growth resumption at high osmotic strength. It was applied to a lager strain and to a previously isolated ethanol-tolerant strain. Fermentation performance of strains was compared at 15 °P wort strength. A selected osmotolerant variant of the ethanol-tolerant strain showed significantly shorter fermentation time than the parent strain, producing 6.45% alcohol by volume beer in 4-5 days with mostly similar organoleptic properties to the original strain. Diacetyl and pentanedione contents were 50-75% and 3-methylbutyl acetate and 2-phenylethyl acetate 50% higher than with the original strain, leading to a small flavour change. The variant contained significantly less intracellular trehalose and glycogen than the parent. Transcriptional analysis of selected genes at 24 h revealed reduced transcription of hexose transport genes and increased transcription of the MALx1 and MALx2 genes, responsible for α-glucoside uptake and metabolism. It is suggested that an attenuated stress response contributes to the improved fermentation performance. Results show that sequential selection for both ethanol tolerance and rapid growth at high osmotic strength can provide strains with enhanced fermentation speed with acceptable product quality. © 2013 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

Reducing barriers to energy efficiency in the German brewing sector. Final report

Energy Technology Data Exchange (ETDEWEB)

Schleich, J; Boede, U; Ostertag, K; Radgen, P

2000-12-01

This report describes the empirical research into barriers to energy efficiency in the German brewing sector. It is one of nine such reports in the BARRIERS project. The report contains description and analysis of five case studies of energy management in German breweries. The results are analysed using the theoretical framework developed for the BARRIERS project. The report also provides brief recommendations on how these barriers to the rational use of energy (RUE) may be overcome and how energy efficiency within the brewing sector may be improved. The results of the study for the brewing sector in Germany are summarised in this executive summary under the following headings: - Characterising the brewing sector - Case studies of energy management in the German brewing sector; - Evidence of barriers in the German brewing sector; - The role of energy service companies in the brewing sector; - Policy implications. (orig.)

Reducing barriers to energy efficiency in the German brewing sector. Executive Summary

Energy Technology Data Exchange (ETDEWEB)

Schleich, J.; Boede, U.; Ostertag, K.; Radgen, P.

2000-12-01

This report describes the empirical research into barriers to energy efficiency in the German brewing sector. It is one of nine such reports in the BARRIERS project. The report contains description and analysis of five case studies of energy management in German breweries. The results are analysed using the theoretical framework developed for the BARRIERS project. The report also provides brief recommendations on how these barriers to the rational use of energy (RUE) may be overcome and how energy efficiency within the brewing sector may be improved. The results of the study for the brewing sector in Germany are summarised in this executive summary under the following headings: - Characterising the brewing sector; - Case studies of energy management in the German brewing sector; - Evidence of barriers in the German brewing sector; - The role of energy service companies in the brewing sector; - Policy implications. (orig.)

Yeast viability and concentration analysis using lens-free computational microscopy and machine learning

Science.gov (United States)

Feizi, Alborz; Zhang, Yibo; Greenbaum, Alon; Guziak, Alex; Luong, Michelle; Chan, Raymond Yan Lok; Berg, Brandon; Ozkan, Haydar; Luo, Wei; Wu, Michael; Wu, Yichen; Ozcan, Aydogan

2017-03-01

Research laboratories and the industry rely on yeast viability and concentration measurements to adjust fermentation parameters such as pH, temperature, and pressure. Beer-brewing processes as well as biofuel production can especially utilize a cost-effective and portable way of obtaining data on cell viability and concentration. However, current methods of analysis are relatively costly and tedious. Here, we demonstrate a rapid, portable, and cost-effective platform for imaging and measuring viability and concentration of yeast cells. Our platform features a lens-free microscope that weighs 70 g and has dimensions of 12 × 4 × 4 cm. A partially-coherent illumination source (a light-emitting-diode), a band-pass optical filter, and a multimode optical fiber are used to illuminate the sample. The yeast sample is directly placed on a complementary metal-oxide semiconductor (CMOS) image sensor chip, which captures an in-line hologram of the sample over a large field-of-view of >20 mm2. The hologram is transferred to a touch-screen interface, where a trained Support Vector Machine model classifies yeast cells stained with methylene blue as live or dead and measures cell viability as well as concentration. We tested the accuracy of our platform against manual counting of live and dead cells using fluorescent exclusion staining and a bench-top fluorescence microscope. Our regression analysis showed no significant difference between the two methods within a concentration range of 1.4 × 105 to 1.4 × 106 cells/mL. This compact and cost-effective yeast analysis platform will enable automatic quantification of yeast viability and concentration in field settings and resource-limited environments.

The use of flocculating brewer's yeast for Cr(III) and Pb(II) removal from residual wastewaters

Energy Technology Data Exchange (ETDEWEB)

Ferraz, A.I.; Teixeira, J.A. [Centro de Engenharia Biologica-IBQF, Universidade do Minho, Braga (Portugal)

1999-11-01

The use of inexpensive biosorbents to sequester heavy metals from aqueous solutions, is one of the most promising technologies being developed to remove these toxic contaminants from wastewaters. Considering this challenge, the viability of Cr(III) and Pb(II) removal from aqueous solutions using a flocculating brewer's yeast residual biomass from a Portuguese brewing industry was studied. The influence of physicochemical factors such as medium pH, biomass concentration and the presence of a co-ion was characterised. Metal uptake kinetics and equilibrium were also analysed, considering different incubation temperatures. For both metals, uptake increased with medium pH, being maximal at 5.0. Optimal biomass concentration for the biosorption process was determined to be 4.5 g dry weight/l. In chromium and lead mixture solutions, competition for yeast binding sites was observed between the two metals, this competition being pH dependent. Yeast biomass showed higher selectivity and uptake capacity to lead. Chromium uptake kinetic was characterised as having a rapid initial step, followed by a slower one. Langmuir model describes well chromium uptake equilibrium. Lead uptake kinetics suggested the presence of mechanisms other than biosorption, possibly including its precipitation. (orig.)

Energy-Saving in Brew-Rectification

Directory of Open Access Journals (Sweden)

N. I. Ulyanau

2008-01-01

Full Text Available The paper investigates dynamics of rectification process on one plate of a column. The basic channels controlling brew-rectification process are described in the paper.The paper also considers problems pertaining to synthesis of an adaptive system that controls non-stationary objects with delay. Synthesis of adaptive systems that automatically control product quality and saving on power resources and productivity with the help of the second method of Lyapunov has been carried out in the paper.Industrial introduction of the given automatic control system of technological process shall permit to increase productivity of a rectification (10–15 %, to decrease specific power consumption by (5–10 % while preserving the specified quality of rectified ethyl alcohol and decrease alcohol losses with luting water and malt-residue.

Innovations in the brewing industry: light beer.

Science.gov (United States)

Blanco, Carlos A; Caballero, Isabel; Barrios, Rosa; Rojas, Antonio

2014-09-01

The demand for light beers has led brewers to innovate by developing light beer. However, these products are not widely accepted in Europe compared to North America and Australasia because of their lack of fullness in the taste and low bitterness compared with conventional beer. The lower levels of some important compounds, present in light beer, can explain these features since they are responsible for the characteristics of the beer. These include alcohol soluble proteins, oligosaccharides, glycerol, polyphenols, iso-α-acids, fusel alcohols and trihydroxy fatty acids. Light beer is produced by several methods, the most commonly used is the addition of glucoamylase to the wort before or during fermentation. This enzyme metabolizes residual carbohydrates (mainly dextrins) transforming them into fermentable sugars and reducing the caloric and alcohol content in this type of beer. Recently pilot studies have been carried out with genetically engineered yeast strains in which amylolytic genes are introduced into the yeast genome in order to metabolize carbohydrate residues. When introducing amylolytic genes, a better fermentability occurs although the fullness of flavor still becomes reduced.

Brewing for Students: An Inquiry-Based Microbiology Lab.

Science.gov (United States)

Sato, Brian K; Alam, Usman; Dacanay, Samantha J; Lee, Amanda K; Shaffer, Justin F

2015-12-01

In an effort to improve and assess student learning, there has been a push to increase the incorporation of discovery-driven modules and those that contain real-world relevance into laboratory curricula. To further this effort, we have developed, implemented, and assessed an undergraduate microbiology laboratory experiment that requires students to use the scientific method while brewing beer. The experiment allows students to brew their own beer and characterize it based on taste, alcohol content, calorie content, pH, and standard reference method. In addition, we assessed whether students were capable of achieving the module learning objectives through a pre-/posttest, student self-evaluation, exam-embedded questions, and an associated worksheet. These objectives included describing the role of the brewing ingredients and predicting how altering the ingredients would affect the characteristics of the beer, amongst others. By completing this experimental module, students accomplished the module objectives, had greater interest in brewing, and were more likely to view beer in scientific terms. Journal of Microbiology & Biology Education.

Yeast Vitality Determination Based on Intracellular NAD(P)H Fluorescence Measurement during Aerobic-Anaerobic Transition

Czech Academy of Sciences Publication Activity Database

Kuřec, M.; Kuncová, Gabriela; Brányik, T.

2009-01-01

Roč. 54, č. 1 (2009), s. 25-29 ISSN 0015-5632 R&D Projects: GA ČR GA104/06/1418; GA MŠk OC 121 Institutional research plan: CEZ:AV0Z40720504 Keywords : continous beer fermentation * brewing yeast * spectroscopy Subject RIV: CE - Biochemistry Impact factor: 0.978, year: 2009

Production of a thermostable 1,3-1,4-β-glucanase mutant in Bacillus subtilis WB600 at a high fermentation capacity and its potential application in the brewing industry.

Science.gov (United States)

Niu, Chengtuo; Liu, Chunfeng; Li, Yongxian; Zheng, Feiyun; Wang, Jinjing; Li, Qi

2018-02-01

1,3-1,4-β-glucanase was an important biotechnological aid in the brewing industry. In a previous research, a Bacillus BglTO mutant (BglTO) with high tolerance towards high temperature and low-pH conditions was constructed and expressed in Escherichia coli. However, E. coli was not a suitable host for enzyme production in food industry. Therefore, the present work aimed to achieve the high-level expression of BglTO in Bacillus subtilis WB600 and to test its effect in Congress mashing. The β-glucanase mutant was successfully expressed in B. subtilis WB600 and favorable plasmid segregation and structural stability were observed. The maximal extracellular activity of β-glucanase in recombinant B. subtilis WB600 reached 4840.4UmL -1 after cultivation condition optimization, which was 1.94-fold higher than that before optimization. The fermentation capacity of recombinant B. subtilis reached 242.02UmL -1 h -1 , which was the highest among all reported β-glucanases. The addition of BglTO in Congress mashing significantly reduced the filtration time and viscosity of mash by 29.7% and 12.3%, respectively, which was superior to two commercial enzymes. These favorable properties indicated that B. subtilis WB600 was a suitable host for production of BglTO, which was promising for application in the brewing industry. Copyright © 2017 Elsevier B.V. All rights reserved.

Understanding the tolerance of the industrial yeast Saccharomyces cerevisiae against a major class of toxic aldehyde compounds.

Science.gov (United States)

Liu, ZongLin Lewis

2018-07-01

Development of the next-generation biocatalyst is vital for fermentation-based industrial applications and a sustainable bio-based economy. Overcoming the major class of toxic compounds associated with lignocellulose-to-biofuels conversion is one of the significant challenges for new strain development. A significant number of investigations have been made to understand mechanisms of the tolerance for industrial yeast. It is humbling to learn how complicated the cell's response to the toxic chemicals is and how little we have known about yeast tolerance in the universe of the living cell. This study updates our current knowledge on the tolerance of industrial yeast against aldehyde inhibitory compounds at cellular, molecular and the genomic levels. It is comprehensive yet specific based on reproducible evidence and cross confirmed findings from different investigations using varied experimental approaches. This research approaches a rational foundation toward a more comprehensive understanding on the yeast tolerance. Discussions and perspectives are also proposed for continued exploring the puzzle of the yeast tolerance to aid the next-generation biocatalyst development.

Identification of beer spoilage microorganisms using the MALDI Biotyper platform.

Science.gov (United States)

Turvey, Michelle Elizabeth; Weiland, Florian; Meneses, Jon; Sterenberg, Nick; Hoffmann, Peter

2016-03-01

Beer spoilage microorganisms present a major risk for the brewing industry and can lead to cost-intensive recall of contaminated products and damage to brand reputation. The applicability of molecular profiling using matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS) in combination with Biotyper software was investigated for the identification of beer spoilage microorganisms from routine brewery quality control samples. Reference mass spectrum profiles for three of the most common bacterial beer spoilage microorganisms (Lactobacillus lindneri, Lactobacillus brevis and Pediococcus damnosus), four commercially available brewing yeast strains (top- and bottom-fermenting) and Dekkera/Brettanomyces bruxellensis wild yeast were established, incorporated into the Biotyper reference library and validated by successful identification after inoculation into beer. Each bacterial species could be accurately identified and distinguished from one another and from over 5600 other microorganisms present in the Biotyper database. In addition, wild yeast contaminations were rapidly detected and distinguished from top- and bottom-fermenting brewing strains. The applicability and integration of mass spectrometry profiling using the Biotyper platform into existing brewery quality assurance practices within industry were assessed by analysing routine microbiology control samples from a local brewery, where contaminating microorganisms could be reliably identified. Brewery-isolated microorganisms not present in the Biotyper database were further analysed for identification using LC-MS/MS methods. This renders the Biotyper platform a promising candidate for biological quality control testing within the brewing industry as a more rapid, high-throughput and cost-effective technology that can be tailored for the detection of brewery-specific spoilage organisms from the local environment.

Glycosylceramide modifies the flavor and metabolic characteristics of sake yeast

Directory of Open Access Journals (Sweden)

Jannatul Ferdouse

2018-05-01

Full Text Available In the manufacture of sake, Japanese traditional rice wine, sake yeast is fermented with koji, which is steamed rice fermented with the non-pathogenic fungus Aspergillus oryzae. During fermentation, sake yeast requires lipids, such as unsaturated fatty acids and sterols, in addition to substances provided by koji enzymes for fermentation. However, the role of sphingolipids on the brewing characteristics of sake yeast has not been studied. In this study, we revealed that glycosylceramide, one of the sphingolipids abundant in koji, affects yeast fermentation. The addition of soy, A. oryzae, and Grifola frondosa glycosylceramide conferred a similar effect on the flavor profiles of sake yeast. In particular, the addition of A. oryzae and G. frondosa glycosylceramide were very similar in terms of the decreases in ethyl caprylate and ethyl 9-decenoate. The addition of soy glycosylceramide induced metabolic changes to sake yeast such as a decrease in glucose, increases in ethanol and glycerol and changes in several amino acids and organic acids concentrations. Tricarboxylic acid (TCA cycle, pyruvate metabolism, starch and sucrose metabolism, and glycerolipid metabolism were overrepresented in the cultures incubated with sake yeast and soy glycosylceramide. This is the first study of the effect of glycosylceramide on the flavor and metabolic profile of sake yeast.

Glycosylceramide modifies the flavor and metabolic characteristics of sake yeast.

Science.gov (United States)

Ferdouse, Jannatul; Yamamoto, Yuki; Taguchi, Seiga; Yoshizaki, Yumiko; Takamine, Kazunori; Kitagaki, Hiroshi

2018-01-01

In the manufacture of sake, Japanese traditional rice wine, sake yeast is fermented with koji, which is steamed rice fermented with the non-pathogenic fungus Aspergillus oryzae . During fermentation, sake yeast requires lipids, such as unsaturated fatty acids and sterols, in addition to substances provided by koji enzymes for fermentation. However, the role of sphingolipids on the brewing characteristics of sake yeast has not been studied. In this study, we revealed that glycosylceramide, one of the sphingolipids abundant in koji, affects yeast fermentation. The addition of soy, A. oryzae , and Grifola frondosa glycosylceramide conferred a similar effect on the flavor profiles of sake yeast. In particular, the addition of A. oryzae and G. frondosa glycosylceramide were very similar in terms of the decreases in ethyl caprylate and ethyl 9-decenoate. The addition of soy glycosylceramide induced metabolic changes to sake yeast such as a decrease in glucose, increases in ethanol and glycerol and changes in several amino acids and organic acids concentrations. Tricarboxylic acid (TCA) cycle, pyruvate metabolism, starch and sucrose metabolism, and glycerolipid metabolism were overrepresented in the cultures incubated with sake yeast and soy glycosylceramide. This is the first study of the effect of glycosylceramide on the flavor and metabolic profile of sake yeast.

Antioxidant N-acetyltransferase Mpr1/2 of industrial baker's yeast enhances fermentation ability after air-drying stress in bread dough.

Science.gov (United States)

Sasano, Yu; Takahashi, Shunsuke; Shima, Jun; Takagi, Hiroshi

2010-03-31

During bread-making processes, yeast cells are exposed to multiple stresses. Air-drying stress is one of the most harmful stresses by generation of reactive oxygen species (ROS). Previously, we discovered that the novel N-acetyltransferase Mpr1/2 confers oxidative stress tolerance by reducing intracellular ROS level in Saccharomyces cerevisiae Sigma1278b strain. In this study, we revealed that Japanese industrial baker's yeast possesses one MPR gene. The nucleotide sequence of the MPR gene in industrial baker's yeast was identical to the MPR2 gene in Sigma1278b strain. Gene disruption analysis showed that the MPR2 gene in industrial baker's yeast is involved in air-drying stress tolerance by reducing the intracellular oxidation levels. We also found that expression of the Lys63Arg and Phe65Leu variants with enhanced enzymatic activity and stability, respectively, increased the fermentation ability of bread dough after exposure to air-drying stress compared with the wild-type Mpr1. In addition, our recent study showed that industrial baker's yeast cells accumulating proline exhibited enhanced freeze tolerance in bread dough. Proline accumulation also enhanced the fermentation ability after air-drying stress treatment in industrial baker's yeast. Hence, the antioxidant enzyme Mpr1/2 could be promising for breeding novel yeast strains that are tolerant to air-drying stress. Copyright 2010 Elsevier B.V. All rights reserved.

Hyphal-like extension and pseudohyphal formation in industrial strains of yeasts induced by isoamyl alcohol

Directory of Open Access Journals (Sweden)

Ceccato-Antonini Sandra Regina

2002-01-01

Full Text Available Yeasts can produce pseudohyphae and hyphal-like extensions under certain growth conditions like isoamyl alcohol (IAA induction, a chief constituent of fusel oil, which is a subproduct from the ethanolic fermentation. The morphology switch from yeast to a filamentous form can be troublesome to the process. In this work it was studied the influence of fusel alcohols, nitrogen sources (ammonium sulphate and leucine and glifosate (a chemical maturator for sugar cane added to a complex medium on some industrial strains of yeasts isolated from the fermentative process. Two industrial strains showed transition to hyphal-like extensions or pseudohyphae (clusters of cells upon addition of IAA from 0.3 to 0.9% /v. The alterations were reversible when the yeasts were reinoculated in YEPD without IAA. Although pseudohyphae are a result of nitrogen-limited medium, we observed them as a result of IAA addition. No influence of the nitrogen source or isopropilic alcohol or glifosate was detected for any strain studied in the concentrations used.

Roasting Effects on Formation Mechanisms of Coffee Brew Melanoidins

NARCIS (Netherlands)

Bekedam, E.K.; Loots, M.J.; Schols, H.A.; Boekel, van M.A.J.S.; Smit, G.

2008-01-01

The effect of the roasting degree on coffee brew melanoidin properties and formation mechanisms was studied. Coffee brew fractions differing in molecular weight (Mw) were isolated from green and light-, medium-, and dark-roasted coffee beans. Isolated fractions were characterized for their

Effect of germination temperatures on proteolysis of the gluten-free grains sorghum and millet during malting and mashing.

Science.gov (United States)

Chiba, Y; Bryce, J H; Goodfellow, V; MacKinlay, J; Agu, R C; Brosnan, J M; Bringhurst, T A; Harrison, B

2012-04-11

Our study showed that sorghum and millet followed a similar pattern of changes when they were malted under similar conditions. When the malt from these cereals was mashed, both cereal types produced wide spectra of substrates (sugars and amino acids) that are required for yeast fermentation when malted at either lower or higher temperatures. At the germination temperatures of 20, 25, and 30 °C used in malting both cereal types, production of reducing sugars and that of free amino nitrogen (FAN) were similar. This is an important quality attribute for both cereals because it implies that variation in temperature during the malting of sorghum and millet, especially when malting temperature is difficult to control, and also reflecting temperature variations, experienced in different countries, will not have an adverse effect on the production and release of amino acids and sugars required by yeast during fermentation. Such consistency in the availability of yeast food (substrates) for metabolism during fermentation when sorghum and millet are malted at various temperatures is likely to reduce processing issues when their malts are used for brewing. Although sorghum has gained wide application in the brewing industry, and has been used extensively in brewing gluten-free beer on industrial scale, this is not the case with millet. The work described here provides novel information regarding the potential of millet for brewing. When both cereals were malted, the results obtained for millet in this study followed patterns similar to those of sorghum. This suggests that millet, in terms of sugars and amino acids, can play a role similar to that of sorghum in the brewing industry. This further suggests that millet, like sorghum, would be a good raw material for brewing gluten-free beer. Inclusion of millet as a brewing raw material will increase the availability of suitable materials (raw material sustainability) for use in the production of gluten-free beer, beverages, and

Applicability of Yeast Extracellular Proteinases in Brewing: Physiological and Biochemical Aspects

Science.gov (United States)

Bilinski, Carl A.; Russell, Inge; Stewart, Graham G.

1987-01-01

A general screening survey for expression of extracellular acid proteinase production was performed on over 100 cultures belonging to the genus Saccharomyces. Although two strains of Saccharomyces cerevisiae showed positive extracellular proteinase phenotypes in plate tests, it was not possible to demonstrate proteolytic activities in cell-free culture supernatants in assays performed at beer pH values. Of several yeasts from other genera examined, Saccharomycopsis fibuligera and Torulopsis magnoliae produced extracellular proteinases with desirable properties. Proteolytic activities were detected in assays performed at beer pH values and at lower temperature. Brewer's wort served as a highly inducing medium for extracellular proteinase production, with T. magnoliae yielding enzyme of highest specific activity. In fact, commencement of enzyme production was detected shortly after the onset of exponential growth in brewer's wort. Inclusion of crude enzyme preparations in brewer's wort inoculated simultaneously with brewer's yeast reduced final ethanol yields slightly and was found to be effective in reducing chill haze formation in bottled beer. PMID:16347298

Relationship of trehalose accumulation with ethanol fermentation in industrial Saccharomyces cerevisiae yeast strains.

Science.gov (United States)

Wang, Pin-Mei; Zheng, Dao-Qiong; Chi, Xiao-Qin; Li, Ou; Qian, Chao-Dong; Liu, Tian-Zhe; Zhang, Xiao-Yang; Du, Feng-Guang; Sun, Pei-Yong; Qu, Ai-Min; Wu, Xue-Chang

2014-01-01

The protective effect and the mechanisms of trehalose accumulation in industrial Saccharomyces cerevisiae strains were investigated during ethanol fermentation. The engineered strains with more intercellular trehalose achieved significantly higher fermentation rates and ethanol yields than their wild strain ZS during very high gravity (VHG) fermentation, while their performances were not different during regular fermentation. The VHG fermentation performances of these strains were consistent with their growth capacity under osmotic stress and ethanol stress, the key stress factors during VHG fermentation. These results suggest that trehalose accumulation is more important for VHG fermentation of industrial yeast strains than regular one. The differences in membrane integrity and antioxidative capacity of these strains indicated the possible mechanisms of trehalose as a protectant under VHG condition. Therefore, trehalose metabolic engineering may be a useful strategy for improving the VHG fermentation performance of industrial yeast strains. Copyright © 2013 Elsevier Ltd. All rights reserved.

Industrially Important Carbohydrate Degrading Enzymes from Yeasts: Pectinases, Chitinases, and β-1,3-Glucanases

Science.gov (United States)

Gummadi, Sathyanarayana N.; Kumar, D. Sunil; Dash, Swati S.; Sahu, Santosh Kumar

Polysaccharide degrading enzymes are hydrolytic enzymes, which have a lot of industrial potential and also play a crucial role in carbon recycling. Pectinases, chitinases and glucanases are the three major polysaccharide degrading enzymes found abundantly in nature and these enzymes are mainly produced by fungal strains. Production of these enzymes by yeasts is advantageous over fungi, because the former are easily amenable to genetic manipulations and time required for growth and production is less than that of the latter. Several yeasts belonging to Saccharomyces, Pichia, Rhodotorula and Cryptococcus produce extracellular pectinases, glucanases and chitinases. This chapter emphasizes on the biological significance of these enzymes, their production and their industrial applications.

Breeding research on sake yeasts in Japan: history, recent technological advances, and future perspectives.

Science.gov (United States)

Kitagaki, Hiroshi; Kitamoto, Katsuhiko

2013-01-01

Sake is an alcoholic beverage of Japan, with a tradition lasting more than 1,300 years; it is produced from rice and water by fermenting with the koji mold Aspergillus oryzae and sake yeast Saccharomyces cerevisiae. Breeding research on sake yeasts was originally developed in Japan by incorporating microbiological and genetic research methodologies adopted in other scientific areas. Since the advent of a genetic paradigm, isolation of yeast mutants has been a dominant approach for the breeding of favorable sake yeasts. These sake yeasts include (a) those that do not form foams (produced by isolating a mutant that does not stick to foams, thus decreasing the cost of sake production); (b) those that do not produce urea, which leads to the formation of ethyl carbamate, a possible carcinogen (isolated by positive selection in a canavanine-, arginine-, and ornithine-containing medium); (c) those that produce an increased amount of ethyl caproate, an apple-like flavor (produced by isolating a mutant resistant to cerulenin, an inhibitor of fatty-acid synthesis); and (d) those that produce a decreased amount of pyruvate (produced by isolating a mutant resistant to an inhibitor of mitochondrial transport, thus decreasing the amount of diacetyl). Given that sake yeasts perform sexual reproduction, sporulation and mating are potent approaches for their breeding. Recently, the genome sequences of sake yeasts have been determined and made publicly accessible. By utilizing this information, the quantitative trait loci (QTLs) for the brewing characteristics of sake yeasts have been identified, which paves a way to DNA marker-assisted selection of the mated strains. Genetic engineering technologies for experimental yeast strains have recently been established by academic groups, and these technologies have also been applied to the breeding of sake yeasts. Sake yeasts whose genomes have been modified with these technologies correspond to genetically modified organisms (GMOs

substrate reduction kinetics and performance evaluation of fluidized

African Journals Online (AJOL)

eobe

takes place during the treatment of waste water by microorganisms in a fluidized takes place ... industrial size- fluidized bed reactor for treatment of brewery waste water. fluidized ... Brewing industry holds a strategic economic position ... brewer yeast and hops for its daily production of beer ... Considering energy costs and.

Brewing for Students: An Inquiry-Based Microbiology Lab.

OpenAIRE

Sato, BK; Alam, U; Dacanay, SJ; Lee, AK; Shaffer, JF

2015-01-01

In an effort to improve and assess student learning, there has been a push to increase the incorporation of discovery-driven modules and those that contain real-world relevance into laboratory curricula. To further this effort, we have developed, implemented, and assessed an undergraduate microbiology laboratory experiment that requires students to use the scientific method while brewing beer. The experiment allows students to brew their own beer and characterize it based on taste, alcohol co...

Design and development of mobile Email system based on brew and IMAP4

International Nuclear Information System (INIS)

Chen Liangchen; Liu Shuzhen; Yan Xiaofei; Sun Gongxing

2007-01-01

In order to achieve IMAP4 support agreement in the mobile e-mail client application on the smart phone, using the Qualcomm introduced wireless devices designed for the BREW platform. Research on the BREW platform mobile and IMAP4 protocol, design and implement the 3G technology standard smart phone e-mail client based on the BREW platform. (authors)

The influence of brewing water characteristic on sensory perception of pour-over local coffee

Science.gov (United States)

Fibrianto, K.; Ardianti, A. D.; Pradipta, K.; Sunarharum, W. B.

2018-01-01

The coffee quality can be characterized by its multisensory perceptions. The content and mineral composition and other substances of brewing water can affect the result of brewed-coffee. The water may influence in extraction capabilities and flavor clarity. The ground Dampit coffee and two commercial instant coffee with pour-over method were used in this study. Various types of commercial drinking water were used to brew the coffee. The result suggests that the different brewing water affects the intensity of sweet and chocolate aroma, as well as oily mouth-feel. Surprisingly, taste and flavour attributes were not affected by the pH of brewing water within the range of 5.5 to 9.1.

Fate of Fusarium Toxins during Brewing.

Science.gov (United States)

Habler, Katharina; Geissinger, Cajetan; Hofer, Katharina; Schüler, Jan; Moghari, Sarah; Hess, Michael; Gastl, Martina; Rychlik, Michael

2017-01-11

Some information is available about the fate of Fusarium toxins during the brewing process, but only little is known about the single processing steps in detail. In our study we produced beer from two different barley cultivars inoculated with three different Fusarium species, namely, Fusarium culmorum, Fusarium sporotrichioides, and Fusarium avenaceum, producing a wide range of mycotoxins such as type B trichothecenes, type A trichothecenes, and enniatins. By the use of multi-mycotoxin LC-MS/MS stable isotope dilution methods we were able to follow the fate of Fusarium toxins during the entire brewing process. In particular, the type B trichothecenes deoxynivalenol, 3-acetyldeoxynivalenol, and 15-acetyldeoxynivalenol showed similar behaviors. Between 35 and 52% of those toxins remained in the beer after filtration. The contents of the potentially hazardous deoxynivalenol-3-glucoside and the type A trichothecenes increased during mashing, but a rapid decrease of deoxynivalenol-3-glucoside content was found during the following steps of lautering and wort boiling. The concentration of enniatins greatly decreased with the discarding of spent grains or finally with the hot break. The results of our study show the retention of diverse Fusarium toxins during the brewing process and allow for assessing the food safety of beer regarding the monitored Fusarium mycotoxins.

Production of Food Grade Yeasts

Directory of Open Access Journals (Sweden)

Argyro Bekatorou

2006-01-01

Full Text Available Yeasts have been known to humans for thousands of years as they have been used in traditional fermentation processes like wine, beer and bread making. Today, yeasts are also used as alternative sources of high nutritional value proteins, enzymes and vitamins, and have numerous applications in the health food industry as food additives, conditioners and flavouring agents, for the production of microbiology media and extracts, as well as livestock feeds. Modern scientific advances allow the isolation, construction and industrial production of new yeast strains to satisfy the specific demands of the food industry. Types of commercial food grade yeasts, industrial production processes and raw materials are highlighted. Aspects of yeast metabolism, with respect to carbohydrate utilization, nutritional aspects and recent research advances are also discussed.

Large-Scale Selection and Breeding To Generate Industrial Yeasts with Superior Aroma Production

Science.gov (United States)

Steensels, Jan; Meersman, Esther; Snoek, Tim; Saels, Veerle

2014-01-01

The concentrations and relative ratios of various aroma compounds produced by fermenting yeast cells are essential for the sensory quality of many fermented foods, including beer, bread, wine, and sake. Since the production of these aroma-active compounds varies highly among different yeast strains, careful selection of variants with optimal aromatic profiles is of crucial importance for a high-quality end product. This study evaluates the production of different aroma-active compounds in 301 different Saccharomyces cerevisiae, Saccharomyces paradoxus, and Saccharomyces pastorianus yeast strains. Our results show that the production of key aroma compounds like isoamyl acetate and ethyl acetate varies by an order of magnitude between natural yeasts, with the concentrations of some compounds showing significant positive correlation, whereas others vary independently. Targeted hybridization of some of the best aroma-producing strains yielded 46 intraspecific hybrids, of which some show a distinct heterosis (hybrid vigor) effect and produce up to 45% more isoamyl acetate than the best parental strains while retaining their overall fermentation performance. Together, our results demonstrate the potential of large-scale outbreeding to obtain superior industrial yeasts that are directly applicable for commercial use. PMID:25192996

A multi-model fusion strategy for multivariate calibration using near and mid-infrared spectra of samples from brewing industry

Science.gov (United States)

Tan, Chao; Chen, Hui; Wang, Chao; Zhu, Wanping; Wu, Tong; Diao, Yuanbo

2013-03-01

Near and mid-infrared (NIR/MIR) spectroscopy techniques have gained great acceptance in the industry due to their multiple applications and versatility. However, a success of application often depends heavily on the construction of accurate and stable calibration models. For this purpose, a simple multi-model fusion strategy is proposed. It is actually the combination of Kohonen self-organizing map (KSOM), mutual information (MI) and partial least squares (PLSs) and therefore named as KMICPLS. It works as follows: First, the original training set is fed into a KSOM for unsupervised clustering of samples, on which a series of training subsets are constructed. Thereafter, on each of the training subsets, a MI spectrum is calculated and only the variables with higher MI values than the mean value are retained, based on which a candidate PLS model is constructed. Finally, a fixed number of PLS models are selected to produce a consensus model. Two NIR/MIR spectral datasets from brewing industry are used for experiments. The results confirms its superior performance to two reference algorithms, i.e., the conventional PLS and genetic algorithm-PLS (GAPLS). It can build more accurate and stable calibration models without increasing the complexity, and can be generalized to other NIR/MIR applications.

Fate of mycotoxins during beer brewing and fermentation.

Science.gov (United States)

Inoue, Tomonori; Nagatomi, Yasushi; Uyama, Atsuo; Mochizuki, Naoki

2013-01-01

Mycotoxins are frequent contaminants of grains, and breweries need, therefore, to pay close attention to the risk of contamination in beer made from such grains as barley and corn. The fate of 14 types of mycotoxin (aflatoxins, fumonisins, ochratoxin A, patulin, trichothecenes, and zearalenone) during beer brewing was investigated in this study. Malt artificially spiked with each mycotoxin was put through the mashing, filtration, boiling and fermentation processes involved in brewing. After brewing, the levels of aflatoxins, ochratoxin A, patulin, and zearalenone were found to have decreased to less than 20% of their initial concentration. They had been adsorbed mainly to the spent grain and removed from the unhopped wort. Additionally, as zearalenone was known, patulin was metabolized to the less toxic compound during the fermentation process. The risk of carry-over to beer was therefore reduced for half of the mycotoxins studied. However, attention still needs to be paid to the risk of trichothecene contamination.

Tolerant industrial yeast Saccharomyces cerevisiae posses a more robust cell wall integrity signaling pathway against 2-furaldehyde and 5-(hydroxymethyl)-2-furaldehyde

Science.gov (United States)

Cell wall integrity signaling pathway in Saccharomyces cerevisiae is a conserved function for detecting and responding to cell stress conditions but less understood for industrial yeast. We dissected gene expression dynamics for a tolerant industrial yeast strain NRRL Y-50049 in response to challeng...

Construction of killer industrial yeast Saccharomyces cerevisiae HAU-1 and its fermentation performance

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Bijender K. Bajaj

2010-06-01

Full Text Available Saccharomyces cerevisiae HAU-1, a time tested industrial yeast possesses most of the desirable fermentation characteristics like fast growth and fermentation rate, osmotolerance, high ethanol tolerance, ability to ferment molasses, and to ferment at elevated temperatures etc. However, this yeast was found to be sensitive against the killer strains of Saccharomyces cerevisiae. In the present study, killer trait was introduced into Saccharomyces cerevisiae HAU-1 by protoplast fusion with Saccharomyces cerevisiae MTCC 475, a killer strain. The resultant fusants were characterized for desirable fermentation characteristics. All the technologically important characteristics of distillery yeast Saccharomyces cerevisiae HAU-1 were retained in the fusants, and in addition the killer trait was also introduced into them. Further, the killer activity was found to be stably maintained during hostile conditions of ethanol fermentations in dextrose or molasses, and even during biomass recycling.

Brewing for Students: An Inquiry-Based Microbiology Lab

Directory of Open Access Journals (Sweden)

Brian K. Sato

2015-08-01

Full Text Available In an effort to improve and assess student learning, there has been a push to increase the incorporation of discovery-driven modules and those that contain real-world relevance into laboratory curricula. To further this effort, we have developed, implemented, and assessed an undergraduate microbiology laboratory experiment that requires students to use the scientific method while brewing beer. The experiment allows students to brew their own beer and characterize it based on taste, alcohol content, calorie content, pH, and standard reference method. In addition, we assessed whether students were capable of achieving the module learning objectives through a pre-/posttest, student self-evaluation, exam-embedded questions, and an associated worksheet. These objectives included describing the role of the brewing ingredients and predicting how altering the ingredients would affect the characteristics of the beer, amongst others. By completing this experimental module, students accomplished the module objectives, had greater interest in brewing, and were more likely to view beer in scientific terms. Editor's Note:The ASM advocates that students must successfully demonstrate the ability to explain and practice safe laboratory techniques. For more information, read the laboratory safety section of the ASM Curriculum Recommendations: Introductory Course in Microbiology and the Guidelines for Biosafety in Teaching Laboratories, available at www.asm.org. The Editors of JMBE recommend that adopters of the protocols included in this article follow a minimum of Biosafety Level 1 practices.

Oxalate content of different drinkable dilutions of tea infusions after different brewing times.

Science.gov (United States)

Lotfi Yagin, Neda; Mahdavi, Reza; Nikniaz, Zeinab

2012-01-01

The aims of this study were to determine the effect of different brewing times and diluting on oxalate content of loose-packed black teas consumed in Tabriz, Iran. The oxalate content of black teas after brewing for 5, 10, 15, 30, 60 minutes was measured in triplicate by enzymatic assay. In order to attain the most acceptable dilution of tea infusions, tea samples which were brewed for 15, 30 and 60 minutes were diluted two (120 ml), three (80 ml) and four (60 ml) times respectively. There was a stepwise increase in oxalate concentrations associated with increased brewing times (Pbrewing times, respectively. There were significant differences between the mean oxalate content of different dilutions after brewing for 15, 30 and 60 minutes (Pbrewing times and different dilution was below the recommended levels. Therefore, it seems that consumption of black tea several times per day would not pose significant health risk in kidney stone patients and susceptible individuals.

Effect of Growth Conditions on Flocculation and Cell Surface Hydrophobicity of Brewing Yeast

Czech Academy of Sciences Publication Activity Database

Kopecká, J.; Němec, M.; Matoulková, D.; Čejka, P.; Jelínková, Markéta; Felsberg, Jürgen; Sigler, Karel

2015-01-01

Roč. 73, č. 2 (2015), s. 143-150 ISSN 0361-0470 Institutional support: RVO:61388971 Keywords : Ale and lager yeast * Cell surface hydrophobicity * FLO genes Subject RIV: EI - Biotechnology ; Bionics Impact factor: 0.492, year: 2015

Determination of pesticide residue transfer rates (percent) from dried tea leaves to brewed tea.

Science.gov (United States)

Wang, Jian; Cheung, Wendy; Leung, Daniel

2014-01-29

This paper presents a study on pesticide residue transfer rates (%) from dried tea leaves to brewed tea. In the study, a brewing procedure simulated the preparation of a hot tea drink as in routine. After brewing, pesticide residues were extracted from brewed tea using a method known as QuEChERS (quick, easy, cheap, effective, rugged, and safe). An UHPLC/ESI-MS/MS method was developed and validated to identify and quantify up to 172 pesticides in both tea leaves and brewed tea samples. Quantification was achieved using matrix-matched standard calibration curves with isotopically labeled standards or a chemical analogue as internal standards, and the calibration curves consisted of six points (0.4, 2.0, 8.0, 16.0, 24.0, and 40.0 μg/L equivalent in sample). The method was validated at four concentration levels (4.0, 12, 20.0, and 32.0 μg/L equivalent in sample) using five different brewed tea matrices on two separate days per matrix. Method performance parameters included overall recovery, intermediate precision, and measurement uncertainty, which were evaluated according to a nested experimental design. Approximately, 95% of the pesticides studied had recoveries between 81 and 110%, intermediate precision ≤20%, and measurement uncertainty ≤40%. From a pilot study of 44 incurred tea samples, pesticide residues were examined for their ability to transfer from dried tea leaves to brewed tea. Each sample, both tea leaves and brewed tea, was analyzed in duplicate. Pesticides were found to have different transfer rates (%). For example, imidacloprid, methomyl, and carbendazim had transfer rates of 84.9, 83.4, and 92.4%, respectively.

Pyruvate Decarboxylase Activity Assay in situ of Different Industrial Yeast Strains

Directory of Open Access Journals (Sweden)

Dorota Kręgiel

2009-01-01

Full Text Available Cytoplasmic pyruvate decarboxylase (PDC, EC 4.1.1.1 is one of the key enzymes of yeast fermentative metabolism. PDC is the first enzyme which, under anaerobic conditions, leads to decarboxylation of pyruvate with acetaldehyde as the end product. The aim of this study is to develop a suitable method for PDC activity assay in situ for different industrial yeast strains. Saccharomyces sp. and Debaryomyces sp. yeast strains grew in fermentative medium with 12 % of glucose. Enzymatic assay was conducted in cell suspension treated with digitonin as permeabilisation agent, and with sodium pyruvate as a substrate, at temperature of 30 °C. Metabolites of PDC pathway were detected using gas chromatographic (GC technique. Various parameters like type and molar concentration of the substrate, minimal effective mass fraction of digitonin, cell concentration, reaction time and effect of pyrazole (alcohol dehydrogenase inhibitor were monitored to optimize PDC enzymatic assay in situ. In the concentration range of yeast cells from 1⋅10^7 to 1⋅10^8 per mL, linear correlation between the produced acetaldehyde and cell density was noticed. Only pyruvate was the specific substrate for pyruvate decarboxylase. In the presence of 0.05 M sodium pyruvate and 0.05 % digitonin, the enzymatic reaction was linear up to 20 min of the assay. During incubation, there was no formation of ethanol and, therefore, pyrazole was not necessary for the assay.

Chemical transformations of characteristic hop secondary metabolites in relation to beer properties and the brewing process: a review.

Science.gov (United States)

Steenackers, Bart; De Cooman, Luc; De Vos, Dirk

2015-04-01

The annual production of hops (Humulus lupulus L.) exceeds 100,000 mt and is almost exclusively consumed by the brewing industry. The value of hops is attributed to their characteristic secondary metabolites; these metabolites are precursors which are transformed during the brewing process into important bittering, aromatising and preservative components with rather low efficiency. By selectively transforming these components off-line, both their utilisation efficiency and functionality can be significantly improved. Therefore, the chemical transformations of these secondary metabolites will be considered with special attention to recent advances in the field. The considered components are the hop alpha-acids, hop beta-acids and xanthohumol, which are components unique to hops, and alpha-humulene and beta-caryophyllene, sesquiterpenes which are highly characteristic of hops. Copyright © 2014 Elsevier Ltd. All rights reserved.

Development of industrial yeast for second generation bioethanol production

Energy Technology Data Exchange (ETDEWEB)

Hou, X

2012-01-15

The cost of lignocellulose-based bioethanol needs to be reduced, in order to commercialize this clean and sustainable fuel substitute for fossil fuels. A microorganism that can completely and efficiently convert all the sugars in lignocellulose into ethanol is one of the prerequisites of a cost-effective production process. In addition, the microorganisms should also have a high tolerance towards the inhibitory compounds present in the lignocellulosic hydrolysate, which are formed during the pretreatment of lignocellulose. Baker's yeast, Saccharomyces cerevisiae, is generally regarded as a robust microorganism and can efficiently ferment glucose. But it lacks the ability to ferment xylose which comprises 20-35% of lignocellulose. Naturally xylose-fermenting yeast such as Pichia stipitis is much more sensitive to inhibitors than S. cerevisiae and it requires accurately controlled microaerophilic conditions during the xylose fermentation, rendering the process technically difficult and expensive. In this study, a novel xylose fermenting yeast Spathaspora passalidarum displayed fast cell growth and efficient xylose fermentation under anaerobic conditions. In contrast, P. stipitis was almost unable to utilize xylose under the same conditions. It is further demonstrated that S. passalidarum converts xylose by means of NADH-preferred xylose reductase (XR) and NAD+-dependent xylitol dehydrogenase (XDH). Thus, the capacity of S. passalidarum to utilize xylose under anaerobic conditions is possibly due to a balance between supply and demand of cofactor through this XR-XDH pathway. Only one other XR with NADH preference has been reported so far. Unfortunately, S. passalidarum also has a low tolerance towards inhibitors generated during pretreatment, which prevents immediate use of this yeast in industrial application. S. passalidarum is able to convert the inhibitor furfural to furfuryl alcohol in a synthetic medium when the addition of furfural is low. The enzymes involved

Development of industrial yeast for second generation bioethanol production

Energy Technology Data Exchange (ETDEWEB)

Hou, X.

2012-01-15

The cost of lignocellulose-based bioethanol needs to be reduced, in order to commercialize this clean and sustainable fuel substitute for fossil fuels. A microorganism that can completely and efficiently convert all the sugars in lignocellulose into ethanol is one of the prerequisites of a cost-effective production process. In addition, the microorganisms should also have a high tolerance towards the inhibitory compounds present in the lignocellulosic hydrolysate, which are formed during the pretreatment of lignocellulose. Baker's yeast, Saccharomyces cerevisiae, is generally regarded as a robust microorganism and can efficiently ferment glucose. But it lacks the ability to ferment xylose which comprises 20-35% of lignocellulose. Naturally xylose-fermenting yeast such as Pichia stipitis is much more sensitive to inhibitors than S. cerevisiae and it requires accurately controlled microaerophilic conditions during the xylose fermentation, rendering the process technically difficult and expensive. In this study, a novel xylose fermenting yeast Spathaspora passalidarum displayed fast cell growth and efficient xylose fermentation under anaerobic conditions. In contrast, P. stipitis was almost unable to utilize xylose under the same conditions. It is further demonstrated that S. passalidarum converts xylose by means of NADH-preferred xylose reductase (XR) and NAD+-dependent xylitol dehydrogenase (XDH). Thus, the capacity of S. passalidarum to utilize xylose under anaerobic conditions is possibly due to a balance between supply and demand of cofactor through this XR-XDH pathway. Only one other XR with NADH preference has been reported so far. Unfortunately, S. passalidarum also has a low tolerance towards inhibitors generated during pretreatment, which prevents immediate use of this yeast in industrial application. S. passalidarum is able to convert the inhibitor furfural to furfuryl alcohol in a synthetic medium when the addition of furfural is low. The enzymes

The use of enzymes for beer brewing: Thermodynamic comparison on resource use

International Nuclear Information System (INIS)

Donkelaar, Laura H.G. van; Mostert, Joost; Zisopoulos, Filippos K.; Boom, Remko M.; Goot, Atze-Jan van der

2016-01-01

The exergetic performance of beer produced by the conventional malting and brewing process is compared with that of beer produced using an enzyme-assisted process. The aim is to estimate if the use of an exogenous enzyme formulation reduces the environmental impact of the overall brewing process. The exergy efficiency of malting was 77%. The main exergy losses stem from the use of natural gas for kilning and from starch loss during germination. The exergy efficiency of the enzyme production process ranges between 20% and 42% depending on if the by-product was considered useful. The main exergy loss was due to high power requirement for fermentation. The total exergy input in the enzyme production process was 30 times the standard chemical exergy of the enzyme, which makes it exergetically expensive. Nevertheless, the total exergy input for the production of 100 kg beer was larger for the conventional process (441 MJ) than for the enzyme-assisted process (354 MJ). Moreover, beer produced using enzymes reduced the use of water, raw materials and natural gas by 7%, 14% and 78% respectively. Consequently, the exergy loss in the enzyme production process is compensated by the prevention of exergy loss in the total beer brewing process. - Highlights: • The exergetic production costs of enzymes are ±30 times their standard chemical exergy. • These costs of enzymes should be taken into account in exergy analysis. • Enzyme-assisted brewing is more exergy efficient than brewing with malted barley. • Enzyme-assisted brewing saves raw material, water and energy.

Isolation and Characterization of Hydrocarbon-Degrading Yeast Strains from Petroleum Contaminated Industrial Wastewater

Science.gov (United States)

Gargouri, Boutheina; Mhiri, Najla; Karray, Fatma; Aloui, Fathi; Sayadi, Sami

2015-01-01

Two yeast strains are enriched and isolated from industrial refinery wastewater. These strains were observed for their ability to utilize several classes of petroleum hydrocarbons substrates, such as n-alkanes and aromatic hydrocarbons as a sole carbon source. Phylogenetic analysis based on the D1/D2 variable domain and the ITS-region sequences indicated that strains HC1 and HC4 were members of the genera Candida and Trichosporon, respectively. The mechanism of hydrocarbon uptaking by yeast, Candida, and Trichosporon has been studied by means of the kinetic analysis of hydrocarbons-degrading yeasts growth and substrate assimilation. Biodegradation capacity and biomass quantity were daily measured during twelve days by gravimetric analysis and gas chromatography coupled with mass spectrometry techniques. Removal of n-alkanes indicated a strong ability of hydrocarbon biodegradation by the isolated yeast strains. These two strains grew on long-chain n-alkane, diesel oil, and crude oil but failed to grow on short-chain n-alkane and aromatic hydrocarbons. Growth measurement attributes of the isolates, using n-hexadecane, diesel oil, and crude oil as substrates, showed that strain HC1 had better degradation for hydrocarbon substrates than strain HC4. In conclusion, these yeast strains can be useful for the bioremediation process and decreasing petroleum pollution in wastewater contaminated with petroleum hydrocarbons. PMID:26339653

Isolation and Characterization of Hydrocarbon-Degrading Yeast Strains from Petroleum Contaminated Industrial Wastewater

Directory of Open Access Journals (Sweden)

Boutheina Gargouri

2015-01-01

Full Text Available Two yeast strains are enriched and isolated from industrial refinery wastewater. These strains were observed for their ability to utilize several classes of petroleum hydrocarbons substrates, such as n-alkanes and aromatic hydrocarbons as a sole carbon source. Phylogenetic analysis based on the D1/D2 variable domain and the ITS-region sequences indicated that strains HC1 and HC4 were members of the genera Candida and Trichosporon, respectively. The mechanism of hydrocarbon uptaking by yeast, Candida, and Trichosporon has been studied by means of the kinetic analysis of hydrocarbons-degrading yeasts growth and substrate assimilation. Biodegradation capacity and biomass quantity were daily measured during twelve days by gravimetric analysis and gas chromatography coupled with mass spectrometry techniques. Removal of n-alkanes indicated a strong ability of hydrocarbon biodegradation by the isolated yeast strains. These two strains grew on long-chain n-alkane, diesel oil, and crude oil but failed to grow on short-chain n-alkane and aromatic hydrocarbons. Growth measurement attributes of the isolates, using n-hexadecane, diesel oil, and crude oil as substrates, showed that strain HC1 had better degradation for hydrocarbon substrates than strain HC4. In conclusion, these yeast strains can be useful for the bioremediation process and decreasing petroleum pollution in wastewater contaminated with petroleum hydrocarbons.

ABOUT A CHOICE OF MATHEMATICAL MODELS OF KINETICS OF CULTIVATION OF SACCHAROMYCES CEREVISIAE YEAST IN THE CONDITIONS OF DEFICIENCY OF OXYGEN

Directory of Open Access Journals (Sweden)

V. B. Tishin

2015-01-01

Full Text Available Summary. In the production technology of many foods microbiological processes are crucial to the economic indicators of enterprises and the quality of the products manufactured. The examples of this are the production, where the biomass is the end product. For example, the production of various strains of the yeast Saccharomyces for different branches of the food industry: baking, brewing, winemaking, as well as for the pharmaceutical industry. The development of mathematical models of microbial cells is one of the greatest challenges of microbiology. The need to search for mathematical models is dictated by the continuous development of microbiological industry, increases in the requirements for the production design, maintenance and predictions of the processes depending on the change of process parameters. However, this requires knowledge of the laws governing material and energy exchange between the culture medium and the cell and the availability of mathematical models describing them. This knowledge cannot be obtained without studying the biological processes kinetics. Kinetic regularities of microbial growth is largely determined by the selection method of the microbiological process and the type of equipment in which these processes occur. Many biological processes can be described with a simple mathematical model, but there are kinetic regularities of biological processes that can only be described by equations of more complex type. Culturing yeast kinetic models, reflecting the complexity of the biological processes occurring during the cultivation were obtained. According to the analysis of experimental data on the Saccharomyces cerevisiae yeast culturing with a batch process, a system of equations (mathematical model, giving a functional relationship of biomass growth and cells consumption of carbohydrates with their different initial values in a culture medium under conditions of oxygen deficiency without stirring is obtained.

Effects of different brewing conditions on catechin content and sensory acceptance in Turkish green tea infusions.

Science.gov (United States)

Saklar, Sena; Ertas, Erdal; Ozdemir, Ibrahim S; Karadeniz, Bulent

2015-10-01

The optimal brewing conditions for Turkish green tea were determined on the basis of extracted catechins and sensory attributes. Green tea infusions were prepared at 75, 85 and 95 °C with brewing times of 1, 2, 3, 5, 10, 20, 30 and 45 min. The amounts of epistructured catechins (EGCG, EGC, ECG, EC), non-epistructured catechins (C, GC, GCG) and caffeine in brewed tea samples were analysed. Sensory analyses were performed by nine trained panelists for infusion colour, taste, aroma and overall acceptability. Brewing at 85 °C for 3 min was found to be the optimal condition, where the EGCG content was at a maximum of 50.69 mg/100 ml with the highest sensory scores. It was observed that the yield of epistructured catechins increased rapidly for the first 3-5 min of brewing at 85 °C, and increased brewing time resulted in a decrease in the yield of epistructured catechins. The amount of nonepistructured catechins continued to increase with longer extraction times. Sensory scores for infusion colour, taste, aroma and overall acceptability were highest at 3 and 5 min brewing times at all temperatures. Sensory scores were very low for 30 and 45 min brewing at 85 and 95 °C due to the bitter taste and dark colour.

Removal of heavy metal from industrial effluents using Baker's yeast

Science.gov (United States)

Ferdous, Anika; Maisha, Nuzhat; Sultana, Nayer; Ahmed, Shoeb

2016-07-01

Bioremediation of wastewater containing heavy metals is one of the major challenges in environmental biotechnology. Heavy metals are not degraded and as a result they remain in the ecosystem, and pose serious health hazards as it comes in contact with human due to anthropogenic activities. Biological treatment with various microorganisms has been practiced widely in recent past, however, accessing and maintaining the microorganisms have always been a challenge. Microorganisms like Baker's yeast can be very promising biosorbents as they offer high surface to volume ratio, large availability, rapid kinetics of adsorption and desorption and low cost. The main aim of this study is to evaluate the applicability of the biosorption process using baker's yeast. Here we present an experimental investigation of biosorption of Chromium (Cr) from water using commercial Baker's Yeast. It was envisaged that yeast, dead or alive, would adsorb heavy metals, however, operating parameters could play vital roles in determining the removal efficiency. Parameters, such as incubation time, pH, amount of biosorbent and heavy metal concentration were varied to investigate the impacts of those parameters on removal efficiency. Rate of removal was found to be inversely proportional to the initial Cr (+6) concentrations but the removal rate per unit biomass was a weakly dependent on initial Cr(+6) concentrations. Biosorption process was found to be more efficient at lower pH and it exhibited lower removal with the increase in solution pH. The optimum incubation time was found to be between 6-8 hours and optimum pH for the metal ion solution was 2. The effluents produced in leather industries are the major source of chromium pollution in Bangladesh and this study has presented a very cost effective yet efficient heavy metal removal approach that can be adopted for such kind of wastewater.

Biotechnology of non-Saccharomyces yeasts--the ascomycetes.

Science.gov (United States)

Johnson, Eric A

2013-01-01

Saccharomyces cerevisiae and several other yeast species are among the most important groups of biotechnological organisms. S. cerevisiae and closely related ascomycetous yeasts are the major producer of biotechnology products worldwide, exceeding other groups of industrial microorganisms in productivity and economic revenues. Traditional industrial attributes of the S. cerevisiae group include their primary roles in food fermentations such as beers, cider, wines, sake, distilled spirits, bakery products, cheese, sausages, and other fermented foods. Other long-standing industrial processes involving S. cerevisae yeasts are production of fuel ethanol, single-cell protein (SCP), feeds and fodder, industrial enzymes, and small molecular weight metabolites. More recently, non-Saccharomyces yeasts (non-conventional yeasts) have been utilized as industrial organisms for a variety of biotechnological roles. Non-Saccharomyces yeasts are increasingly being used as hosts for expression of proteins, biocatalysts and multi-enzyme pathways for the synthesis of fine chemicals and small molecular weight compounds of medicinal and nutritional importance. Non-Saccharomyces yeasts also have important roles in agriculture as agents of biocontrol, bioremediation, and as indicators of environmental quality. Several of these products and processes have reached commercial utility, while others are in advanced development. The objective of this mini-review is to describe processes currently used by industry and those in developmental stages and close to commercialization primarily from non-Saccharomyces yeasts with an emphasis on new opportunities. The utility of S. cerevisiae in heterologous production of selected products is also described.

Yeast Metabolites of Glycated Amino Acids in Beer.

Science.gov (United States)

Hellwig, Michael; Beer, Falco; Witte, Sophia; Henle, Thomas

2018-06-01

Glycation reactions (Maillard reactions) during the malting and brewing processes are important for the development of the characteristic color and flavor of beer. Recently, free and protein-bound Maillard reaction products (MRPs) such as pyrraline, formyline, and maltosine were found in beer. Furthermore, these amino acid derivatives are metabolized by Saccharomyces cerevisiae via the Ehrlich pathway. In this study, a method was developed for quantitation of individual Ehrlich intermediates derived from pyrraline, formyline, and maltosine. Following synthesis of the corresponding reference material, the MRP-derived new Ehrlich alcohols pyrralinol (up to 207 μg/L), formylinol (up to 50 μg/L), and maltosinol (up to 6.9 μg/L) were quantitated for the first time in commercial beer samples by reverse phase high performance liquid chromatography tandem mass spectrometry in the multiple reaction monitoring mode. This is equivalent to ca. 20-40% of the concentrations of the parent glycated amino acids. The metabolites were almost absent from alcohol-free beers and malt-based beverages. Two previously unknown valine-derived pyrrole derivatives were characterized and qualitatively identified in beer. The metabolites investigated represent new process-induced alkaloids that may influence brewing yeast performance due to structural similarities to quorum sensing and metal-binding molecules.

Brewing with 100 % unmalted grains: barley, wheat, oat and rye

DEFF Research Database (Denmark)

Zhuang, Shiwen; Shetty, Radhakrishna; Hansen, Mikkel

2017-01-01

of fermentable wort carbohydrates were observed in the worts (all at ca. 12°P), and in particular oat wort had lower concentration of maltose compared to the others, resulting in the lowest concentration of alcohol in final beer. Moreover, wort made from unmalted grains also showed lower free amino nitrogen......Whilst beers have been produced using various levels of unmalted grains as adjuncts along with malt, brewing with 100 % unmalted grains in combination with added mashing enzymes remains mostly unknown. The aim of this study was to investigate the brewing potential of 100 % unmalted barley, wheat......, oat and rye in comparison with 100 % malt. To address this, identical brewing methods were adopted at 10-L scale for each grain type by applying a commercial mashing enzyme blend (Ondea® Pro), and selected quality attributes were assessed for respective worts and beers. Different compositions...

Efficient Implementation of the Pairing on Mobilephones Using BREW

Science.gov (United States)

Yoshitomi, Motoi; Takagi, Tsuyoshi; Kiyomoto, Shinsaku; Tanaka, Toshiaki

Pairing based cryptosystems can accomplish novel security applications such as ID-based cryptosystems, which have not been constructed efficiently without the pairing. The processing speed of the pairing based cryptosystems is relatively slow compared with the other conventional public key cryptosystems. However, several efficient algorithms for computing the pairing have been proposed, namely Duursma-Lee algorithm and its variant ηT pairing. In this paper, we present an efficient implementation of the pairing over some mobilephones. Moreover, we compare the processing speed of the pairing with that of the other standard public key cryptosystems, i. e. RSA cryptosystem and elliptic curve cryptosystem. Indeed the processing speed of our implementation in ARM9 processors on BREW achieves under 100 milliseconds using the supersingular curve over F397. In addition, the pairing is more efficient than the other public key cryptosystems, and the pairing can be achieved enough also on BREW mobilephones. It has become efficient enough to implement security applications, such as short signature, ID-based cryptosystems or broadcast encryption, using the pairing on BREW mobilephones.

Breeding of lager yeast with Saccharomyces cerevisiae improves stress resistance and fermentation performance.

Science.gov (United States)

Garcia Sanchez, Rosa; Solodovnikova, Natalia; Wendland, Jürgen

2012-08-01

Lager beer brewing relies on strains collectively known as Saccharomyces carlsbergensis, which are hybrids between S. cerevisiae and S. eubayanus-like strains. Lager yeasts are particularly adapted to low-temperature fermentations. Selection of new yeast strains for improved traits or fermentation performance is laborious, due to the allotetraploid nature of lager yeasts. Initially, we have generated new F1 hybrids by classical genetics, using spore clones of lager yeast and S. cerevisiae and complementation of auxotrophies of the single strains upon mating. These hybrids were improved on several parameters, including growth at elevated temperature and resistance against high osmolarity or high ethanol concentrations. Due to the uncertainty of chromosomal make-up of lager yeast spore clones, we introduced molecular markers to analyse mating-type composition by PCR. Based on these results, new hybrids between a lager and an ale yeast strain were isolated by micromanipulation. These hybrids were not subject to genetic modification. We generated and verified 13 hybrid strains. All of these hybrid strains showed improved stress resistance as seen in the ale parent, including improved survival at the end of fermentation. Importantly, some of the strains showed improved fermentation rates using 18° Plato at 18-25°C. Uniparental mitochondrial DNA inheritance was observed mostly from the S. cerevisiae parent. Copyright © 2012 John Wiley & Sons, Ltd.

Tracking polysaccharides through the brewing process

NARCIS (Netherlands)

Fangel, Jonatan U.; Eiken, Jens; Sierksma, Aafje; Schols, Henk A.; Willats, William G.T.; Harholt, Jesper

2018-01-01

Brewing is a highly complex stepwise process that starts with a mashing step during which starch is gelatinized and converted into oligo- and/or monosaccharides by enzymes and heat. The starch is mostly degraded and utilised during the fermentation process, but grains and hops both contain

40 CFR 63.2164 - If I monitor brew ethanol, what are my monitoring installation, operation, and maintenance...

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 12 2010-07-01 2010-07-01 true If I monitor brew ethanol, what are my... monitor brew ethanol, what are my monitoring installation, operation, and maintenance requirements? (a... considered by us to be generally optimum. Use the brew-to-exhaust correlation equation established under § 63...

Genetic dissection of grain traits in Yamadanishiki, an excellent sake-brewing rice cultivar.

Science.gov (United States)

Okada, Satoshi; Suehiro, Miki; Ebana, Kaworu; Hori, Kiyosumi; Onogi, Akio; Iwata, Hiroyoshi; Yamasaki, Masanori

2017-12-01

The grain traits of Yamadanishiki, an excellent sake-brewing rice cultivar in Japan, are governed by multiple QTLs, namely, a total of 42 QTLs including six major QTLs. Japanese rice wine (sake) is produced using brewing rice (Oryza sativa L.) that carries traits desirable for sake-brewing, such as a larger grain size and higher white-core expression rate (WCE) compared to cooking rice cultivars. However, the genetic basis for these traits in brewing rice cultivars is still unclear. We performed analyses of quantitative trait locus (QTL) of grain and days to heading over 3 years on populations derived from crosses between Koshihikari, a cooking rice, and Yamadanishiki, an excellent sake-brewing rice. A total of 42 QTLs were detected for the grain traits, and the Yamadanishiki alleles at 16 QTLs contributed to larger grain size. Two major QTLs essential for regulating both 100-grain weight (GWt) and grain width (GWh) were harbored in the same regions on chromosomes 5 and 10. An interaction was noted between the environment and the QTL associated with WCE on chromosome 6, which was detected in two of 3 years. In addition, two QTLs for WCE on chromosomes 3 and 10 overlapped with the QTLs for GWt and GWh, suggesting that QTLs associated with grain size also play an important role in the formation of white-core. Despite differences in the rate of grain growth in both Koshihikari and Yamadanishiki across 2 years, the WCE in Yamadanishiki remained consistent, thus demonstrating that the formation of white-core does not depend on grain filling speed. These data can be informative for programs involved in breeding better cooking and brewing rice cultivars.

The influence of different types of preparation (espresso and brew) on coffee aroma and main bioactive constituents.

Science.gov (United States)

Caprioli, Giovanni; Cortese, Manuela; Sagratini, Gianni; Vittori, Sauro

2015-01-01

Coffee is one of the most popular hot drinks in the world; it may be prepared by several methods, but the most common forms are boiled (brew) and pressurized (espresso). Analytical studies on the substances responsible for the pleasant aroma of roasted coffee have been carried out for more than 100 years. Brew coffee and espresso coffee (EC) have a different and peculiar aroma profile, demonstrating the importance of the brewing process on the final product sensorial quality. Concerning bioactive compounds, the extraction mechanism plays a crucial role. The differences in the composition of coffee brew in chlorogenic acids and caffeine content is the result of the different procedures of coffee preparation. The aim of the present review is to detail how the brewing process affects coffee aroma and composition.

Reuse of waste beer yeast sludge for biosorptive decolorization of reactive blue 49 from aqueous solution.

Science.gov (United States)

Wang, Baoe; Guo, Xiu

2011-06-01

Reactive blue 49 was removed from aqueous solution by biosorption using powder waste sludge composed of Saccharomyces cerevisiae from the beer-brewing industry. The effect of initial pH, temperature and the biosorption thermodynamics, equilibrium, kinetics was investigated in this study. It was found that the biosorption capacity was at maximum at initial pH 3, that the effect of temperature on biosorption of reactive blue 49 was only slight in relation to the large biosorption capacity (25°C, 361 mg g(-1)) according as the biosorption capacity decreased only 43 mg g(-1) at the temperature increased from 25 to 50°C. The biosorption was spontaneous, exothermic in nature and the dye molecules movements decreased slightly in random at the solid/liquid interface during the biosorption of dye on biosorbents. The biosorption equilibrium data could be described by Freundich isotherm model. The biosorption rates were found to be consistent with a pseudo-second-order kinetics model. The functional group interaction analysis between waste beer yeast sludge and reactive blue 49 by the aid of Fourier transform infrared (abbr. FTIR) spectroscopy indicated that amino components involved in protein participated in the biosorption process, which may be achieved by the mutual electrostatic adsorption process between the positively charged amino groups in waste beer yeast sludge with negatively charged sulfonic groups in reactive blue 49.

Effects of brewing conditions on the antioxidant capacity of twenty-four commercial green tea varieties.

Science.gov (United States)

Sharpe, Erica; Hua, Fang; Schuckers, Stephanie; Andreescu, Silvana; Bradley, Ryan

2016-02-01

A novel paper-based Nanoceria Reducing Antioxidant Capacity (NanoCerac) assay for antioxidant detection (Sharpe, Frasco, Andreescu, & Andreescu, 2012), has been adapted for the first time as a high-throughput method, in order to measure the effect of brewing conditions and re-infusion on the antioxidant capacity of twenty-four commercial green teas. The oxygen radical absorbance capacity (ORAC) assay, frequently applied to complex foods and beverages, was used as a comparator measure of antioxidant capacity. A novel measure of sustained antioxidant capacity, the total inherent antioxidant capacity (TI-NanoCerac and TI-ORAC) was measured by infusing each tea six times. Effects of brewing conditions (temperature, brew time, etc.) were assessed using one popular tea as a standard. Both NanoCerac and ORAC assays correlated moderately (R(2) 0.80 ± 0.19). The average first-brew NanoCerac, TI-NanoCerac, first-brew ORAC and TI-ORAC were: 0.73 ± 0.1 GAE/g tea; 2.4 ± 0.70 mmolGAE/g tea; 1.0 ± 0.3 mmolTE/g tea and 2.1 ± 0.71 mmolTE/g tea respectively. Brewing conditions including water temperature and infusion time significantly affected antioxidant capacity. The high-throughput adaptation of the original NanoCerac assay tested here offered advantages over ORAC, including portability and rapid analysis. Copyright © 2015 Elsevier Ltd. All rights reserved.

Physical characteristics of the paper filter and low cafestol content filter coffee brews.

Science.gov (United States)

Rendón, Mery Yovana; Dos Santos Scholz, Maria Brígida; Bragagnolo, Neura

2018-06-01

The results found in the literature concerning the effect of consuming filter coffee brews on increasing the blood cholesterol levels due to the presence of diterpenes, are divergent. Thus the present research evaluated the diterpene (cafestol and kahweol) concentrations in filter coffee brews prepared with paper filters of different sizes, colors and origins (Brazil, Japan, The United States of America, Germany, France and the Netherlands), with and without micro perforations. This is the first study that reports the physical characteristics of paper filter and its importance to obtain filter coffee brew with low cafestol content. Thus, a sample of Catuai cultivar coffee with high cafestol content was roasted to a medium-light degree and used to prepare the brews in a 1:10 ratio (coffee powder to water). The diterpenes were extracted by direct saponification and quantified and identified by HPLC-DAD-MS/MS. The paper filters were physically characterized by measuring their grammage, and the fat permeation rate calculated in order to better understand the differences between the filters which allow one to obtain higher or lower diterpene contents. The cafestol and kahweol concentrations in the brews varied from 1.62 to 2.98 mg/L and from 0.73 to 1.96 mg/L, respectively. The highest cafestol and kahweol concentrations were obtained using paper filters with micro perforations, considering similar sized paper filters. The paper filters showed high fat permeability and grammages between 50.46 and 67.48 g/m 2 . The diterpene retention capacities of the filters produced in the different countries were similar. The results showed that the porosity of the paper filter and the particle size of the ground roasted coffee were determinant factors in obtaining filter coffee brews with lower cafestol contents. Copyright © 2018 Elsevier Ltd. All rights reserved.

Variability of some diterpene esters in coffee beverages as influenced by brewing procedures.

Science.gov (United States)

Moeenfard, Marzieh; Erny, Guillaume L; Alves, Arminda

2016-11-01

Several coffee brews, including classical and commercial beverages, were analyzed for their diterpene esters content (cafestol and kahweol linoleate, oleate, palmitate and stearate) by high performance liquid chromatography with diode array detector (HPLC-DAD) combined with spectral deconvolution. Due to the coelution of cafestol and kahweol esters at 225 nm, HPLC-DAD did not give accurate quantification of cafestol esters. Accordingly, spectral deconvolution was used to deconvolve the co-migrating profiles. Total cafestol and kahweol esters content of classical coffee brews ranged from 5-232 to 2-1016 mg/L, respectively. Commercial blends contained 1-54 mg/L of total cafestol esters and 2-403 mg/L of total kahweol esters. Boiled coffee had the highest diterpene esters content, while filtered and instant brews showed the lowest concentrations. However, individual diterpene esters content was not affected by brewing procedure as in terms of kahweol esters, kahweol palmitate was the main compound in all samples, followed by kahweol linoleate, oleate and stearate. Higher amounts of cafestol palmitate and stearate were also observed compared to cafestol linoleate and cafestol oleate. The ratio of diterpene esters esterified with unsaturated fatty acids to total diterpene esters was considered as measure of their unsaturation in analyzed samples which varied from 47 to 52%. Providing new information regarding the diterpene esters content and their distribution in coffee brews will allow a better use of coffee as a functional beverage.

Further development of the cassette-based pYC plasmid system by incorporation of the dominant hph, nat and AUR1-C gene markers and the lacZ reporter system

DEFF Research Database (Denmark)

Hansen, J.; Felding, T.; Johannesen, P.F.

2003-01-01

to the use of G418 resistance. We found the markers to be of use not only in standard laboratory strains of Saccharomyces cerevisiae but also in an industrial strain of S. carlsbergensis (syn. of S. pastorianus) brewing yeast as well as in Saccharomyces kluyveri. As the pYC system contains means of counter...

Primary souring: a novel bacteria-free method for sour beer production

OpenAIRE

Caputo, Robert; Osburn, Kara; Amaral, Justin; Metcalf, Sara; Nickens, David; Rogers, Cody; Sausen, Christopher; Miller, Justin; Li, Hongde; Tennessen, Jason; Bochman, Matthew

2017-01-01

In the beverage fermentation industry, especially at the craft or micro level, there is a movement to incorporate as many local ingredients as possible to both capture terroir and stimulate local economies. In the case of craft beer, this has traditionally only encompassed locally sourced barley, hops, and other agricultural adjuncts. The identification and use of novel yeasts in brewing lags behind. We sought to bridge this gap by bio-prospecting for wild yeasts, with a focus on the American...

Evolutionary History of Ascomyceteous Yeasts

Energy Technology Data Exchange (ETDEWEB)

Haridas, Sajeet; Riley, Robert; Salamov, Asaf; Goker, Markus; Klenk, Hans-Peter; Kurtzman, Cletus P.; Blackwell, Meredith; Grigoriev, Igor; Jeffries, Thomas W.

2014-06-06

Yeasts are important for many industrial and biotechnological processes and show remarkable diversity despite morphological similarities. We have sequenced the genomes of 16 ascomycete yeasts of taxonomic and industrial importance including members of Saccharomycotina and Taphrinomycotina. A comparison of these with several other previously published yeast genomes have added increased confidence to the phylogenetic positions of previously poorly placed species including Saitoella complicata, Babjeviella inositovora and Metschnikowia bicuspidata. Phylogenetic analysis also showed that yeasts with alternative nuclear codon usage where CUG encodes serine instead of leucine are monophyletic within the Saccharomycotina. Most of the yeasts have compact genomes with a large fraction of single exon genes with Lipomyces starkeyi and the previously published Pneumocystis jirovecii being notable exceptions. Intron analysis suggests that early diverging species have more introns. We also observed a large number of unclassified lineage specific non-simple repeats in these genomes.

40 CFR 63.2166 - How do I demonstrate initial compliance with the emission limitations if I monitor brew ethanol?

Science.gov (United States)

2010-07-01

... with the emission limitations if I monitor brew ethanol? 63.2166 Section 63.2166 Protection of... demonstrate initial compliance with the emission limitations if I monitor brew ethanol? (a) You must... subpart. (b) You must establish the brew-to-exhaust correlation for each fermentation stage according to...

Interactions Between Industrial Yeasts and Chemical Contaminants in Grape Juice Affect Wine Composition Profile

Directory of Open Access Journals (Sweden)

Etjen Bizaj

2014-01-01

Full Text Available The interaction between four industrial wine yeast strains and grape juice chemical contaminants during alcoholic fermentation was studied. Industrial strains of Saccharomyces cerevisiae (AWRI 0838, S. cerevisiae mutant with low H2S production phenotype (AWRI 1640, interspecies hybrid of S. cerevisiae and S. kudriavzevii (AWRI 1539 and a hybrid of AWRI 1640 and AWRI 1539 (AWRI 1810 were exposed separately to fungicides pyrimethanil (Pyr, 10 mg/L and fenhexamid (Fhx, 10 mg/L, as well as to the most common toxin produced by moulds on grapes, ochratoxin A (OTA, 5 μg/L, during alcoholic fermentation of Vitis vinifera L. cv. Sauvignon blanc juice. Contaminants were found to strongly impair fermentation performance and metabolic activity of all yeast strains studied. The chemical profile of wine was analyzed by HPLC (volatile acidity, concentrations of ethanol, fructose, glucose, glycerol and organic acids and the aromatic profile was analyzed using a stable isotope dilution technique using GC/MS (ethyl esters, acetates and aromatic alcohols and Kitagawa tubes (H2S. The chemical composition of wine with added contaminants was in all cases significantly different from the control. Of particular note is that the quantity of aromatic compounds produced by yeast was significantly lower. Yeast’s capacity to remove contaminants from wine at the end of the alcoholic fermentation, and after extended contact (7 days was determined. All the strains were able to remove contaminants from the media, moreover, after extended contact, the concentration of contaminants was in most cases lower.

The Geographic Distribution of Saccharomyces cerevisiae Isolates within three Italian Neighboring Winemaking Regions Reveals Strong Differences in Yeast Abundance, Genetic Diversity and Industrial Strain Dissemination

Directory of Open Access Journals (Sweden)

Alessia Viel

2017-08-01

Full Text Available In recent years the interest for natural fermentations has been re-evaluated in terms of increasing the wine terroir and managing more sustainable winemaking practices. Therefore, the level of yeast genetic variability and the abundance of Saccharomyces cerevisiae native populations in vineyard are becoming more and more crucial at both ecological and technological level. Among the factors that can influence the strain diversity, the commercial starter release that accidentally occur in the environment around the winery, has to be considered. In this study we led a wide scale investigation of S. cerevisiae genetic diversity and population structure in the vineyards of three neighboring winemaking regions of Protected Appellation of Origin, in North-East of Italy. Combining mtDNA RFLP and microsatellite markers analyses we evaluated 634 grape samples collected over 3 years. We could detect major differences in the presence of S. cerevisiae yeasts, according to the winemaking region. The population structures revealed specificities of yeast microbiota at vineyard scale, with a relative Appellation of Origin area homogeneity, and transition zones suggesting a geographic differentiation. Surprisingly, we found a widespread industrial yeast dissemination that was very high in the areas where the native yeast abundance was low. Although geographical distance is a key element involved in strain distribution, the high presence of industrial strains in vineyard reduced the differences between populations. This finding indicates that industrial yeast diffusion it is a real emergency and their presence strongly interferes with the natural yeast microbiota.

Evaluation of microbial diversity in the pilot-scale beer brewing process by culture-dependent and culture-independent method.

Science.gov (United States)

Takahashi, M; Kita, Y; Kusaka, K; Mizuno, A; Goto-Yamamoto, N

2015-02-01

In the brewing industry, microbial management is very important for stabilizing the quality of the product. We investigated the detailed microbial community of beer during fermentation and maturation, to manage beer microbiology in more detail. We brewed a beer (all-malt) and two beerlike beverages (half- and low-malt) in pilot-scale fermentation and investigated the microbial community of them using a next-generation sequencer (454 GS FLX titanium), quantitative PCR, flow cytometry and a culture-dependent method. From 28 to 88 genera of bacteria and from 9 to 38 genera of eukaryotic micro-organisms were detected in each sample. Almost all micro-organisms died out during the boiling process. However, bacteria belonging to the genera Acidovorax, Bacillus, Brevundimonas, Caulobacter, Chryseobacterium, Methylobacterium, Paenibacillus, Polaromonas, Pseudomonas, Ralstonia, Sphingomonas, Stenotrophomonas, Tepidimonas and Tissierella were detected at the early and middle stage of fermentation, even though their cell densities were low (below approx. 10(3) cells ml(-1) ) and they were not almost detected at the end of fermentation. We revealed that the microbial community of beer during fermentation and maturation is very diverse and several bacteria possibly survive during fermentation. In this study, we revealed the detailed microbial communities of beer using next-generation sequencing. Some of the micro-organisms detected in this study were found in beer brewing process for the first time. Additionally, the possibility of growth of several bacteria at the early and middle stage of fermentation was suggested. © 2014 The Society for Applied Microbiology.

Influence of integral and decaffeinated coffee brews on metabolic parameters of rats fed with hiperlipidemic diets

Directory of Open Access Journals (Sweden)

Júlia Ariana de Souza Gomes

2013-10-01

Full Text Available The objective of this study was to evaluate the influence of integral and decaffeinated coffee brews (Coffea arabica L and C. canephora Pierre on the metabolic parameters of rats fed with hyperlipidemic diet. Thirty male Wistar rats (initial weight of 270 g ± 20 g were used in the study, which were divided into six groups five each. The treatments were normal diet, hyperlipidemic diet, hyperlipidemic diet associated with integral coffee arabica or canephora brews (7.2 mL/kg/day and hyperlipidemic diet associated to decaffeinated arabica, or canephora brews, using the same dosage. After 41 days, performance analyses were conducted.The rats were then euthanized and the carcasses were used for the analysis of dried ether extract and crude protein. Fractions of adipose tissue were processed for histological analysis. There was a reduction in weight gain and accumulation of lipids in the carcasses, lower diameter of adipocytes and a lower relative weight of the liver and kidneys of rats fed with hyperlipidemic diet associated with integral coffee brew. Integral coffee brew reduced the obesity in the rats receiving hyperlipidemic diet, but the same effect did not occur with the decaffeinated types.

Genomic insights into the Saccharomyces sensu stricto complex.

Science.gov (United States)

Borneman, Anthony R; Pretorius, Isak S

2015-02-01

The Saccharomyces sensu stricto group encompasses species ranging from the industrially ubiquitous yeast Saccharomyces cerevisiae to those that are confined to geographically limited environmental niches. The wealth of genomic data that are now available for the Saccharomyces genus is providing unprecedented insights into the genomic processes that can drive speciation and evolution, both in the natural environment and in response to human-driven selective forces during the historical "domestication" of these yeasts for baking, brewing, and winemaking. Copyright © 2015 by the Genetics Society of America.

Bioactive composition and antioxidant potential of different commonly consumed coffee brews affected by their preparation technique and milk addition.

Science.gov (United States)

Niseteo, Tena; Komes, Draženka; Belščak-Cvitanović, Ana; Horžić, Dunja; Budeč, Maja

2012-10-15

Coffee is one of the most popular beverages in the world, prepared and consumed in many different ways. Taste, aroma and composition of the coffee brew vary depending on the preparation method. Therefore, this study investigates the effect of different brewing methods on the polyphenol and methylxanthine composition and antioxidant capacity of thirteen different coffee brews. The content of total phenols and flavonoids was determined spectrophotometrically and the content of chlorogenic acid derivates (3-CQA, 4-CQA and 5-CQA) and caffeine using the high performance liquid chromatography (HPLC-PDA). Antioxidant capacity of coffee brews was evaluated by using the ABTS (2,2-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid)) and FRAP (ferric-reducing antioxidant power) assays. Instant coffee brews showed the highest values in content of total phenols, chlorogenic acid derivates, caffeine and antioxidant capacity, which significantly decreased by milk addition. The antioxidant capacity of coffee brews was in compliance with the total phenol content and content of chlorogenic acid derivates. Copyright © 2012 Elsevier Ltd. All rights reserved.

Restoration of Traditional Korean Nuruk and Analysis of the Brewing Characteristics.

Science.gov (United States)

Lee, Jang-Eun; Lee, Ae Ran; Kim, HyeRyun; Lee, Eunjung; Kim, Tae Wan; Shin, Woo Chang; Kim, Jae Ho

2017-05-28

In this study, a total of 58 different kinds of nuruk (a traditional Korean fermentation starter) were prepared, including 46 kinds of restored nuruk from ancient documents. Each nuruk was evaluated by analysis of its saccharification power, and the enzyme activities of glucoamylase, α-amylase, β-amylase, protease, and β-glucanase. The range of saccharification power (sp) of the restored nuruk ranged between 85 and 565 sp. The diastatic enzymes, α-amylase, β-amylase, and glucoamylase, were significantly correlated to the saccharification power value; conversely, β-glucanase and protease did not have a correlative relationship with saccarification power. In addition, their brewing properties on chemical and organoleptic aspects of traditional alcoholic beverage production were compared. Each raw and supplementary material contained in nuruk showed its own unique characteristics on Korean alcoholic beverage brewing. For the first time, in this study, the traditional Korean nuruk types mentioned in ancient documents were restored using modernized production methods, and also characterized based on their brewing properties. Our results could be utilized as a basis for further study of traditional alcoholic beverages and their valuable microorganisms.

Awa1p on the cell surface of sake yeast inhibits biofilm formation and the co-aggregation between sake yeasts and Lactobacillus plantarum ML11-11.

Science.gov (United States)

Hirayama, Satoru; Shimizu, Masashi; Tsuchiya, Noriko; Furukawa, Soichi; Watanabe, Daisuke; Shimoi, Hitoshi; Takagi, Hiroshi; Ogihara, Hirokazu; Morinaga, Yasushi

2015-05-01

We examined mixed-species biofilm formation between Lactobacillus plantarum ML11-11 and both foaming and non-foaming mutant strains of Saccharomyces cerevisiae sake yeasts. Wild-type strains showed significantly lower levels of biofilm formation compared with the non-foaming mutants. Awa1p, a protein involved in foam formation during sake brewing, is a glycosylphosphatidylinositol (GPI)-anchored protein and is associated with the cell wall of sake yeasts. The AWA1 gene of the non-foaming mutant strain Kyokai no. 701 (K701) has lost the C-terminal sequence that includes the GPI anchor signal. Mixed-species biofilm formation and co-aggregation of wild-type strain Kyokai no. 7 (K7) were significantly lower than K701 UT-1 (K701 ura3/ura3 trp1/trp1), while the levels of strain K701 UT-1 carrying the AWA1 on a plasmid were comparable to those of K7. The levels of biofilm formation and co-aggregation of the strain K701 UT-1 harboring AWA1 with a deleted GPI anchor signal were similar to those of K701 UT-1. These results clearly demonstrate that Awa1p present on the surface of sake yeast strain K7 inhibits adhesion between yeast cells and L. plantarum ML11-11, consequently impeding mixed-species biofilm formation. Copyright © 2014 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Late-maturing cooking rice Sensyuraku has excellent properties, equivalent to sake rice, for high-quality sake brewing.

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Anzawa, Yoshihiko; Satoh, Kenji; Satoh, Yuko; Ohno, Satomi; Watanabe, Tsutomu; Katsumata, Kazuaki; Kume, Kazunori; Watanabe, Ken-Ichi; Mizunuma, Masaki; Hirata, Dai

2014-01-01

Low protein content and sufficient grain rigidity are desired properties for the rice used in high-quality sake brewing such as Daiginjo-shu (polishing ratio of the rice, less than 50%). Two kinds of rice, sake rice (SR) and cooking rice (CR), have been used for sake brewing. Compared with those of SR, analyses of CR for high-quality sake brewing using highly polished rice have been limited. Here we described the original screening of late-maturing CR Sensyuraku (SEN) as rice with low protein content and characterization of its properties for high-quality sake brewing. The protein content of SEN was lower than those of SR Gohyakumangoku (GOM) and CR Yukinosei (YUK), and its grain rigidity was higher than that of GOM. The excellent properties of SEN with respect to both water-adsorption and enzyme digestibility were confirmed using a Rapid Visco Analyzer (RVA). Further, we confirmed a clear taste of sake produced from SEN by sensory evaluation. Thus, SEN has excellent properties, equivalent to those of SR, for high-quality sake brewing.

Fermentation of Apple Juice with a Selected Yeast Strain Isolated from the Fermented Foods of Himalayan Regions and Its Organoleptic Properties.

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Kanwar, S S; Keshani

2016-01-01

Twenty-three Saccharomyces cerevisiae strains isolated from different fermented foods of Western Himalayas have been studied for strain level and functional diversity in our department. Among these 23 strains, 10 S. cerevisiae strains on the basis of variation in their brewing traits were selected to study their organoleptic effect at gene level by targeting ATF1 gene, which is responsible for ester synthesis during fermentation. Significant variation was observed in ATF1 gene sequences, suggesting differences in aroma and flavor of their brewing products. Apple is a predominant fruit in Himachal Pradesh and apple cider is one of the most popular drinks all around the world hence, it was chosen for sensory evaluation of six selected yeast strains. Organoleptic studies and sensory analysis suggested Sc21 and Sc01 as best indigenous strains for soft and hard cider, respectively, indicating their potential in enriching the local products with enhanced quality.

Simplified Mashing Efficiency. Novel Method for Optimization of Food Industry Wort Production with the Use of Adjuncts

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Szwed Łukasz P.

2014-09-01

Full Text Available Malt extracts and malt concentrates have a broad range of application in food industry. Those products are obtained by methods similar to brewing worts. The possible reduction of cost can be achieved by application of malt substitutes likewise in brewing industry. As the malt concentrates for food industry do not have to fulfill strict norms for beer production it is possible to produce much cheaper products. It was proved that by means of mathematic optimization it is possible to determine the optimal share of unmalted material for cheap yet effective production of wort.

The wine and beer yeast Dekkera bruxellensis.

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Schifferdecker, Anna Judith; Dashko, Sofia; Ishchuk, Olena P; Piškur, Jure

2014-09-01

Recently, the non-conventional yeast Dekkera bruxellensis has been gaining more and more attention in the food industry and academic research. This yeast species is a distant relative of Saccharomyces cerevisiae and is especially known for two important characteristics: on the one hand, it is considered to be one of the main spoilage organisms in the wine and bioethanol industry; on the other hand, it is 'indispensable' as a contributor to the flavour profile of Belgium lambic and gueuze beers. Additionally, it adds to the characteristic aromatic properties of some red wines. Recently this yeast has also become a model for the study of yeast evolution. In this review we focus on the recently developed molecular and genetic tools, such as complete genome sequencing and transformation, to study and manipulate this yeast. We also focus on the areas that are particularly well explored in this yeast, such as the synthesis of off-flavours, yeast detection methods, carbon metabolism and evolutionary history. © 2014 The Authors. Yeast published by John Wiley & Sons, Ltd.

Catechin Composition and Antioxidant Activity of Black Teas in Relation to Brewing Time.

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Koch, Wojciech; Kukula-Koch, Wirginia; Głowniak, Kazimierz

2017-11-01

Black tea infusions are one of the most popular beverages across the world. Their extract composition depends on several factors, brewing time being one of the most important determinants. The aim of the present study was to determine the catechin composition of different black tea infusions using a validated LC electrospray ionization time-of-flight MS method. Additionally, total phenolic content (TPC) and antioxidant activity of infusions were evaluated using Folin-Ciocalteu reagent and stable radical 2,2-diphenyl-1-picrylhydrazyl (DPPH). An optimized LC-MS method enabled the precise identification of the studied catechins [epicatechin (EC), EC gallate (ECG), epigallocatechin (EGC), and epigallocatechin-3-gallate (EGCG)] and gallic acid (GA). The major catechin in all investigated teas was EGC (25.6 mg/100 cm3 after 4 min of brewing). EC was present at the lowest concentration in all extracts. TPC and antiradical scavenging activity were in a good agreement with catechins and GA content. In general, the longer the brewing time, the higher the concentration of catechin, TPC, and antioxidant activity values. However, it should be noted that after 2 min brewing, most phenolics had already been extracted, and extract composition did not significantly change at a prolonged extraction time.

Integrated approach for selecting efficient Saccharomyces cerevisiae for industrial lignocellulosic fermentations: Importance of yeast chassis linked to process conditions.

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Costa, Carlos E; Romaní, Aloia; Cunha, Joana T; Johansson, Björn; Domingues, Lucília

2017-03-01

In this work, four robust yeast chassis isolated from industrial environments were engineered with the same xylose metabolic pathway. The recombinant strains were physiologically characterized in synthetic xylose and xylose-glucose medium, on non-detoxified hemicellulosic hydrolysates of fast-growing hardwoods (Eucalyptus and Paulownia) and agricultural residues (corn cob and wheat straw) and on Eucalyptus hydrolysate at different temperatures. Results show that the co-consumption of xylose-glucose was dependent on the yeast background. Moreover, heterogeneous results were obtained among different hydrolysates and temperatures for each individual strain pointing to the importance of designing from the very beginning a tailor-made yeast considering the specific raw material and process. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effect of different brewing times on soluble oxalate content of loose-packed black teas and tea bags.

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Mahdavi, Reza; Lotfi Yagin, Neda; Liebman, Michael; Nikniaz, Zeinab

2013-02-01

Because of the postulated role of increased dietary oxalate intake in calcium oxalate stone formation, the effect of different brewing times on soluble oxalate contents of loose-packed black tea and tea bags was studied. The oxalate content of 25 different samples of loose-packed black teas after brewing at 5, 10, 15, 30, and 60 min and of ten brands of tea bags after infusion for 1, 2, 3, 4, and 5 min was measured by enzymatic assay. The oxalate concentration resulting from different brewing times ranged from 4.3 to 6.2 mg/240 ml for loose-packed black teas and from 2.7 to 4.8 mg/240 ml for tea bags. There was a stepwise increase in oxalate concentration associated with increased brewing times.

Advertising and Concentration in the Brewing Industry

DEFF Research Database (Denmark)

Madsen, Erik Strøjer; Wu, Yanqing

2014-01-01

The paper tracks the development in industry concentrations from 2002 to 2012, discusses some of the main drivers behind this development and points to economies of scale in advertising as a main pay-off from mergers and acquisitions. Using firm-level data both from the American market and the wo......The paper tracks the development in industry concentrations from 2002 to 2012, discusses some of the main drivers behind this development and points to economies of scale in advertising as a main pay-off from mergers and acquisitions. Using firm-level data both from the American market...

Industrial systems biology and its impact on synthetic biology of yeast cell factories.

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Fletcher, Eugene; Krivoruchko, Anastasia; Nielsen, Jens

2016-06-01

Engineering industrial cell factories to effectively yield a desired product while dealing with industrially relevant stresses is usually the most challenging step in the development of industrial production of chemicals using microbial fermentation processes. Using synthetic biology tools, microbial cell factories such as Saccharomyces cerevisiae can be engineered to express synthetic pathways for the production of fuels, biopharmaceuticals, fragrances, and food flavors. However, directing fluxes through these synthetic pathways towards the desired product can be demanding due to complex regulation or poor gene expression. Systems biology, which applies computational tools and mathematical modeling to understand complex biological networks, can be used to guide synthetic biology design. Here, we present our perspective on how systems biology can impact synthetic biology towards the goal of developing improved yeast cell factories. Biotechnol. Bioeng. 2016;113: 1164-1170. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

Fermentation of biomass sugars to ethanol using native industrial yeast strains.

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Yuan, Dawei; Rao, Kripa; Relue, Patricia; Varanasi, Sasidhar

2011-02-01

In this paper, the feasibility of a technology for fermenting sugar mixtures representative of cellulosic biomass hydrolyzates with native industrial yeast strains is demonstrated. This paper explores the isomerization of xylose to xylulose using a bi-layered enzyme pellet system capable of sustaining a micro-environmental pH gradient. This ability allows for considerable flexibility in conducting the isomerization and fermentation steps. With this method, the isomerization and fermentation could be conducted sequentially, in fed-batch, or simultaneously to maximize utilization of both C5 and C6 sugars and ethanol yield. This system takes advantage of a pH-dependent complexation of xylulose with a supplemented additive to achieve up to 86% isomerization of xylose at fermentation conditions. Commercially-proven Saccharomyces cerevisiae strains from the corn-ethanol industry were used and shown to be very effective in implementation of the technology for ethanol production. Copyright © 2010 Elsevier Ltd. All rights reserved.

Difference Spectroscopy in the Analysis of the Effects of Coffee Cherry Processing Variables on the Flavor of Brewed Coffee

International Nuclear Information System (INIS)

Lyman, D.J.; Benck, R.M.; Merle, S.F.

2011-01-01

Infrared difference spectroscopy was used to study how changes in the processing of Arabica coffee cherries into green beans affected the flavor of coffee brewed from roasted green beans. Paired samples of green beans, in which the drying step or fermentation/washing step in their processing was altered, were roasted and brewed in a standard manner and their ATR-FT-IR spectra obtained. Difference spectra of the 1800 to 1680 cm-1 carbonyl region of water-subtracted spectra of paired samples of these brewed coffees provided data which indicated differences in brewed coffee flavor due to changes in fermentation/washing steps and drying steps involved in the processing of coffee cherries. The role of acid, ketone, aldehyde, ester, lactone, and vinyl ester carbonyl components on the flavor of brewed coffee is proposed that is consistent with the flavors as perceived by the coffee tasters.

Difference Spectroscopy in the Analysis of the Effects of Coffee Cherry Processing Variables on the Flavor of Brewed Coffee

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Donald J. Lyman

2011-01-01

Full Text Available Infrared difference spectroscopy was used to study how changes in the processing of Arabica coffee cherries into green beans affected the flavor of coffee brewed from roasted green beans. Paired samples of green beans, in which the drying step or fermentation/washing step in their processing was altered, were roasted and brewed in a standard manner and their ATR-FT-IR spectra obtained. Difference spectra of the 1800 to 1680 cm−1 carbonyl region of water-subtracted spectra of paired samples of these brewed coffees provided data which indicated differences in brewed coffee flavor due to changes in fermentation/washing steps and drying steps involved in the processing of coffee cherries. The role of acid, ketone, aldehyde, ester, lactone, and vinyl ester carbonyl components on the flavor of brewed coffee is proposed that is consistent with the flavors as perceived by the coffee tasters.

How does yeast respond to pressure?

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Fernandes P.M.B.

2005-01-01

Full Text Available The brewing and baking yeast Saccharomyces cerevisiae has been used as a model for stress response studies of eukaryotic cells. In this review we focus on the effect of high hydrostatic pressure (HHP on S. cerevisiae. HHP exerts a broad effect on yeast cells characteristic of common stresses, mainly associated with protein alteration and lipid bilayer phase transition. Like most stresses, pressure induces cell cycle arrest. Below 50 MPa (500 atm yeast cell morphology is unaffected whereas above 220 MPa wild-type cells are killed. S. cerevisiae cells can acquire barotolerance if they are pretreated with a sublethal stress due to temperature, ethanol, hydrogen peroxide, or pressure. Nevertheless, pressure only leads to protection against severe stress if, after pressure pretreatment, the cells are also re-incubated at room pressure. We attribute this effect to the inhibition of the protein synthesis apparatus under HHP. The global genome expression analysis of S. cerevisiae cells submitted to HHP revealed a stress response profile. The majority of the up-regulated genes are involved in stress defense and carbohydrate metabolism while most repressed genes belong to the cell cycle progression and protein synthesis categories. However, the signaling pathway involved in the pressure response is still to be elucidated. Nitric oxide, a signaling molecule involved in the regulation of a large number of cellular functions, confers baroprotection. Furthermore, S. cerevisiae cells in the early exponential phase submitted to 50-MPa pressure show induction of the expression level of the nitric oxide synthase inducible isoform. As pressure becomes an important biotechnological tool, studies concerning this kind of stress in microorganisms are imperative.

Disruption of the yeast ATH1 gene confers better survival after dehydration, freezing, and ethanol shock: potential commercial applications.

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Kim, J; Alizadeh, P; Harding, T; Hefner-Gravink, A; Klionsky, D J

1996-01-01

The accumulation of trehalose is a critical determinant of stress resistance in the yeast Saccharomyces cerevisiae. We have constructed a yeast strain in which the activity of the trehalose-hydrolyzing enzyme, acid trehalase (ATH), has been abolished. Loss of ATH activity was accomplished by disrupting the ATH1 gene, which is essential for ATH activity. The delta ath1 strain accumulated greater levels of cellular trehalose and grew to a higher cell density than the isogenic wild-type strain. In addition, the elevated levels of trehalose in the delta ath1 strain correlated with increased tolerance to dehydration, freezing, and toxic levels of ethanol. The improved resistance to stress conditions exhibited by the delta ath1 strain may make this strain useful in commercial applications, including baking and brewing. PMID:8633854

A reference model systesm of industrial yeasts Saccharomyces cerevisiae is needed for development of the next-generation biocatalyst toward advanced biofuels production

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Diploid industrial yeast Saccharomyces cerevisiae has demonstrated distinct characteristics that differ from haploid laboratory model strains. However, as a workhorse for a broad range of fermentation-based industrial applications, it was poorly characterized at the genome level. Observations on the...

Biotechnology of non-Saccharomyces yeasts-the basidiomycetes.

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Johnson, Eric A

2013-09-01

Yeasts are the major producer of biotechnology products worldwide, exceeding production in capacity and economic revenues of other groups of industrial microorganisms. Yeasts have wide-ranging fundamental and industrial importance in scientific, food, medical, and agricultural disciplines (Fig. 1). Saccharomyces is the most important genus of yeast from fundamental and applied perspectives and has been expansively studied. Non-Saccharomyces yeasts (non-conventional yeasts) including members of the Ascomycetes and Basidiomycetes also have substantial current utility and potential applicability in biotechnology. In an earlier mini-review, "Biotechnology of non-Saccharomyces yeasts-the ascomycetes" (Johnson Appl Microb Biotechnol 97: 503-517, 2013), the extensive biotechnological utility and potential of ascomycetous yeasts are described. Ascomycetous yeasts are particularly important in food and ethanol formation, production of single-cell protein, feeds and fodder, heterologous production of proteins and enzymes, and as model and fundamental organisms for the delineation of genes and their function in mammalian and human metabolism and disease processes. In contrast, the roles of basidiomycetous yeasts in biotechnology have mainly been evaluated only in the past few decades and compared to the ascomycetous yeasts and currently have limited industrial utility. From a biotechnology perspective, the basidiomycetous yeasts are known mainly for the production of enzymes used in pharmaceutical and chemical synthesis, for production of certain classes of primary and secondary metabolites such as terpenoids and carotenoids, for aerobic catabolism of complex carbon sources, and for bioremediation of environmental pollutants and xenotoxicants. Notwithstanding, the basidiomycetous yeasts appear to have considerable potential in biotechnology owing to their catabolic utilities, formation of enzymes acting on recalcitrant substrates, and through the production of unique primary

Genomic Evolution of the Ascomycete Yeasts

Energy Technology Data Exchange (ETDEWEB)

Riley, Robert; Haridas, Sajeet; Salamov, Asaf; Boundy-Mills, Kyria; Goker, Markus; Hittinger, Chris; Klenk, Hans-Peter; Lopes, Mariana; Meir-Kolthoff, Jan P.; Rokas, Antonis; Rosa, Carlos; Scheuner, Carmen; Soares, Marco; Stielow, Benjamin; Wisecaver, Jennifer H.; Wolfe, Ken; Blackwell, Meredith; Kurtzman, Cletus; Grigoriev, Igor; Jeffries, Thomas

2015-03-16

Yeasts are important for industrial and biotechnological processes and show remarkable metabolic and phylogenetic diversity despite morphological similarities. We have sequenced the genomes of 16 ascomycete yeasts of taxonomic and industrial importance including members of Saccharomycotina and Taphrinomycotina. Phylogenetic analysis of these and previously published yeast genomes helped resolve the placement of species including Saitoella complicata, Babjeviella inositovora, Hyphopichia burtonii, and Metschnikowia bicuspidata. Moreover, we find that alternative nuclear codon usage, where CUG encodes serine instead of leucine, are monophyletic within the Saccharomycotina. Most of the yeasts have compact genomes with a large fraction of single exon genes, and a tendency towards more introns in early-diverging species. Analysis of enzyme phylogeny gives insights into the evolution of metabolic capabilities such as methanol utilization and assimilation of alternative carbon sources.

Genomic Sequence of Saccharomyces cerevisiae BAW-6, a Yeast Strain Optimal for Brewing Barley Shochu.

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Kajiwara, Yasuhiro; Mori, Kazuki; Tashiro, Kosuke; Higuchi, Yujiro; Takegawa, Kaoru; Takashita, Hideharu

2018-04-05

Here, we report the draft genome sequence of Saccharomyces cerevisiae strain BAW-6, which is used for the production of barley shochu, a traditional Japanese spirit. This genomic information can be used to elucidate the genetic basis underlying the high alcohol production capacity and citric acid tolerance of shochu yeast. Copyright © 2018 Kajiwara et al.

Occurrence of furan in coffee from Spanish market: Contribution of brewing and roasting.

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Altaki, M S; Santos, F J; Galceran, M T

2011-06-15

In this work, we evaluated the occurrence of furan in brews obtained from regular, decaffeinated, and instant coffee and commercial packed capsules. For this purpose, a previously developed automated headspace solid-phase microextraction method coupled to gas chromatography-mass spectrometry (HS-SPME-GC-MS) was used. Initially, the influence of HS-SPME conditions on furan formation was evaluated. In addition, the effect of roasting conditions (temperature and time) used for coffee beans on furan formation was also studied. We found that low temperature and long roasting time (140°C and 20min) decreases the final furan content. Furan concentrations in regular ground coffee brews from an espresso coffee machine were higher (43-146ng/ml) than those obtained from a home drip coffee maker (20 and 78ng/ml), while decaffeinated coffee brews from a home drip coffee maker (14-65ng/ml) showed a furan concentration similar to that obtained from regular coffee. Relatively low concentrations of this compound (12-35ng/ml) were found in instant coffee brews, while commercial packed coffee capsules showed the highest concentrations (117-244ng/ml). Finally, the daily intake of furan through coffee consumption in Barcelona (Spain) (0.03-0.38μg/kg of body weight) was estimated. Copyright © 2010 Elsevier Ltd. All rights reserved.

Engineered Trx2p industrial yeast strain protects glycolysis and fermentation proteins from oxidative carbonylation during biomass propagation

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Gómez-Pastor Rocío

2012-01-01

Full Text Available Abstract Background In the yeast biomass production process, protein carbonylation has severe adverse effects since it diminishes biomass yield and profitability of industrial production plants. However, this significant detriment of yeast performance can be alleviated by increasing thioredoxins levels. Thioredoxins are important antioxidant defenses implicated in many functions in cells, and their primordial functions include scavenging of reactive oxygen species that produce dramatic and irreversible alterations such as protein carbonylation. Results In this work we have found several proteins specifically protected by yeast Thioredoxin 2 (Trx2p. Bidimensional electrophoresis and carbonylated protein identification from TRX-deficient and TRX-overexpressing cells revealed that glycolysis and fermentation-related proteins are specific targets of Trx2p protection. Indeed, the TRX2 overexpressing strain presented increased activity of the central carbon metabolism enzymes. Interestingly, Trx2p specifically preserved alcohol dehydrogenase I (Adh1p from carbonylation, decreased oligomer aggregates and increased its enzymatic activity. Conclusions The identified proteins suggest that the fermentative capacity detriment observed under industrial conditions in T73 wine commercial strain results from the oxidative carbonylation of specific glycolytic and fermentation enzymes. Indeed, increased thioredoxin levels enhance the performance of key fermentation enzymes such as Adh1p, which consequently increases fermentative capacity.

High-level production of β-1,3-1,4-glucanase by Rhizomucor miehei under solid-state fermentation and its potential application in the brewing industry.

Science.gov (United States)

Yang, S Q; Xiong, H; Yang, H Y; Yan, Q J; Jiang, Z Q

2015-01-01

To improve the β-1,3-1,4-glucanase production by Rhizomucor miehei under solid-state fermentation (SSF) for industrial application. The fermentation conditions for β-1,3-1,4-glucanase production by R. miehei CAU432 under SSF were optimized using a 'one-factor-at-a-time' method. Under the optimized fermentation conditions, viz. oatmeal (0·45-0·9 mm) as sole carbon source, 5% (w/w) peptone as sole nitrogen source, initial moisture of 80% (w/w), initial culture pH of 5·0, incubation temperature of 50°C and incubation time of 6 days, the highest β-1,3-1,4-glucanase activity of 20,025 U g(-1) dry substrate was achieved, which represents the highest yield for β-1,3-1,4-glucanase production ever reported. The crude enzyme was extracted and purified to homogeneity with a purification fold of 4·6 and a recovery yield of 9·0%. The addition of the purified β-1,3-1,4-glucanase in mash obviously reduced its filtration time (24·6%) and viscosity (2·61%). The optimal fermentation conditions for maximal β-1,3-1,4-glucanase production under SSF was obtained, and the enzyme was suitable for application in the malting process. The high production yield and excellent capability of the enzyme may enable it great potential in industries, especially in brewing industry. © 2014 The Society for Applied Microbiology.

Ways of Light Industry Development

Institute of Scientific and Technical Information of China (English)

Tang Jintao

2009-01-01

@@ "The planning of the right industry restructuring and revitalization" was officially released on May 18th this year. This planning mainly includes food, cereals, oil, batteries, leather, paper, fermentation, brewing, sugar refining and home electrical appliances. As a response to a comprehensive action plan, the planning period is from 2009 to 2011.

A new method for Espresso Coffee brewing: Caffè Firenze

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Alessandro Parenti

2013-09-01

Full Text Available Espresso coffee is the most popular choice for Italian coffee consumers. It has been estimated that every day, in the world, over of 50 million of Espresso cups are taken. As a consequence of this success, a large number of devices to make Espresso have been developed. In this scenario, a new device has been recently developed and patented (Eu. Patent 06 023 798.9; US 2010/0034942 A1. This brew method, named “Caffè Firenze”, uses a sealed extraction chamber, where water and gas provides pressure higher than the other extraction methods. Three main parts compose the apparatus: the gas source, the extraction chamber and the heat exchanger. The gas source provides the pressured gas required to raise the pressure of the system. The extraction chamber is made with chrome-brass and accessorized with two heating glow plugs. Many are the factors affecting Espresso quality: it is known that, coffee type, roasting conditions and degree, grinding and storage strongly affect the obtained brew. Also, several studies have been carried out on the effect of the setting parameters on quality, for example water pressure, water temperature, and brew time. Among the characteristics that determine Espresso quality, the main attribute for the visual analysis is, without doubts, the foam, also called “crema”. Indeed, height, aspect, and persistency of foam are features much appreciates by consumers. Two distinguish Espresso foam parameters are the persistency and foam index. Equipping a commercial bar machine with the new designed extraction chamber makes feasible the comparison between the traditional way to brew Espresso and the new device. The comparison was made holding the previous mentioned conditions, and differences were evaluated in terms of physical parameters and aromatic profiles. Caffè Firenze shows pronounced differences compared with traditional Espresso in term of foam-related parameters. Also, the new extraction device produces coffees with

Influence of temperature and brewing time of nettle (Urtica dioica L.) infusions on vitamin C content

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Wolska, Jolanta; Czop, Michał; Jakubczyk, Karolina; Janda, Katarzyna

Stinging nettle (Urtica dioica L.) can be found in temperate climate zones of Europe, Africa and America Nettle may be a source of nutritional ingredients, mineral salts, vitamins and antioxidants. The aim of the study was to determine the effect of temperature and brewing time Urtica dioica L. infusions from different parts of this plant on vitamin C (ascorbic acid) content. Infusions of nettle leaf, stem and root were prepared at room temperature, 50°C, 60°C, 70°C and 80°C for 10 minutes. Leaf infusions were also brewed for 5, 10, 15 and 20 minutes at initial water temperature of 60°C. The amount of vitamin C was determined by the spectrophotometric method. The best temperature of brewing nettle infusions, in terms of vitamin C concentration, is between 50 °C and 60 °C as it is sufficient to extract the substance, yet not high enough to destroy it. The optimal time of brewing appeared to be 10 minutes as the prolonged exposure to high temperature appeared to be detrimental for ascorbic acid as well.

Microbiological and biochemical survey on the transition of fermentative processes in Fukuyama pot vinegar brewing.

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Okazaki, Sachiko; Furukawa, Soichi; Ogihara, Hirokazu; Kawarai, Taketo; Kitada, Chika; Komenou, Akiko; Yamasaki, Makari

2010-06-01

Traditional brewing of Fukuyama pot vinegar is a process that has been continued in Fukuyama, Kagoshima, Japan, for almost 200 years. The entire process proceeds from raw materials, including steamed rice, rice koji (steamed rice grown with a fungus, Aspergillus oryzae) and water, to produce vinegar in roughly capped large pots laid in the open air. No special fermentative manipulation is required, except for scattering dried rice koji (called furi-koji) on the surface of the mash to form a cap-like mat on the surface at the start of brewing. As the biochemical mechanism of the natural transition of the fermentative processes during brewing has not been fully explained, we conducted a microbiological and biochemical study on the transition. First, a distinct biochemical change was observed in the brewing of spring preparation; that is, a sharp decline in pH from 6.5 to 3.5 within the first 5 days of brewing was observed due to lactic acid fermentation. Alcoholic fermentation also proceeded with a sharp increase to 4.5% ethanol within the first 5 days under the acidic conditions, suggesting that saccharification and both fermentations proceed in parallel. Acidic conditions and ethanol accumulation restricted the growth of most microorganisms in the mash, and in turn provided a favorable growth condition for acetic acid bacteria which are acid resistant and "ethanol-philic." Acetic acid was detected from day 16 and gradually increased in concentration, reaching a maximum of 7% at day 70 that was maintained thereafter. Empirically furi-koji naturally sinks into the mash after around day 40 by an unknown mechanism, allowing acetic acid bacteria to easily form pellicles on the mash surface and promoting efficient acetic acid fermentation. Dominant microbial species involved in the three fermentations were identified by denaturing gradient gel electrophoresis analysis using PCR-amplified defined-regions of small rDNA from microorganisms in the brewing mash or colony

Furan in roasted, ground and brewed coffee

Science.gov (United States)

Gruczyńska, Eliza; Kowalska, Dorota; Kozłowska, Mariola; Majewska, Ewa; Tarnowska, Katarzyna

2018-01-01

Coffee is the most popular hot beverage in the world. The annual coffee production in 2010, 2014 and 2016 was 8.1, 9.0 and 9.3 million tons respectively. There are more than 100 coffee species, but only two of them: Arabica (Coffea arabica) and Robusta (Coffea canephora) have gained commercial importance. During roasting of green coffee beans not only desirable compounds are formed, that exert positive influence on the taste and flavour of coffee, but also small quantities of undesirable ones. Furan (C4H4O) is one of the latter. Furan is a volatile compound (boiling temp. of 31.4 oC) formed during thermal processing of food. The toxicity of furan has been well documented and it is classified as “possible human carcinogen” (Group 2B) by the International Agency for Research on Cancer. Various pathways have been reported for furan formation during food processing. It can be formed from carbohydrates, amino acids by their thermal degradation or thermal re-arrangement and by oxidation of ascorbic acid and polyunsaturated acids and carotenoids. High concentrations of furan have been reported in coffee, baked and roasted food and in food subjected to preserving in cans and jars. Furan levels in brewed coffee are typically near or below 120 μg/L, but it can approach thousands μg/kg in roasted whole beans or ground coffee. The highest concentration of furan in roasted coffee reaches the level of 7000 μg/kg. Taking into account that coffee is the most popular hot drink, it becomes the main contributor to furan exposure from dietary sources for adults. In this article the published scientific papers concerned with the presence of furan in roasted non-brewed and brewed coffee have been reviewed. The formation mechanisms and occurrence of furan in coffee and the harmful influence of furan on the consumer health have been discussed.

Metabolic engineering of a haploid strain derived from a triploid industrial yeast for producing cellulosic ethanol.

Science.gov (United States)

Kim, Soo Rin; Skerker, Jeffrey M; Kong, In Iok; Kim, Heejin; Maurer, Matthew J; Zhang, Guo-Chang; Peng, Dairong; Wei, Na; Arkin, Adam P; Jin, Yong-Su

2017-03-01

Many desired phenotypes for producing cellulosic biofuels are often observed in industrial Saccharomyces cerevisiae strains. However, many industrial yeast strains are polyploid and have low spore viability, making it difficult to use these strains for metabolic engineering applications. We selected the polyploid industrial strain S. cerevisiae ATCC 4124 exhibiting rapid glucose fermentation capability, high ethanol productivity, strong heat and inhibitor tolerance in order to construct an optimal yeast strain for producing cellulosic ethanol. Here, we focused on developing a general approach and high-throughput screening method to isolate stable haploid segregants derived from a polyploid parent, such as triploid ATCC 4124 with a poor spore viability. Specifically, we deleted the HO genes, performed random sporulation, and screened the resulting segregants based on growth rate, mating type, and ploidy. Only one stable haploid derivative (4124-S60) was isolated, while 14 other segregants with a stable mating type were aneuploid. The 4124-S60 strain inherited only a subset of desirable traits present in the parent strain, same as other aneuploids, suggesting that glucose fermentation and specific ethanol productivity are likely to be genetically complex traits and/or they might depend on ploidy. Nonetheless, the 4124-60 strain did inherit the ability to tolerate fermentation inhibitors. When additional genetic perturbations known to improve xylose fermentation were introduced into the 4124-60 strain, the resulting engineered strain (IIK1) was able to ferment a Miscanthus hydrolysate better than a previously engineered laboratory strain (SR8), built by making the same genetic changes. However, the IIK1 strain showed higher glycerol and xylitol yields than the SR8 strain. In order to decrease glycerol and xylitol production, an NADH-dependent acetate reduction pathway was introduced into the IIK1 strain. By consuming 2.4g/L of acetate, the resulting strain (IIK1A

Deciphering the Origin, Evolution, and Physiological Function of the Subtelomeric Aryl-Alcohol Dehydrogenase Gene Family in the Yeast Saccharomyces cerevisiae.

Science.gov (United States)

Yang, Dong-Dong; de Billerbeck, Gustavo M; Zhang, Jin-Jing; Rosenzweig, Frank; Francois, Jean-Marie

2018-01-01

Homology searches indicate that Saccharomyces cerevisiae strain BY4741 contains seven redundant genes that encode putative aryl-alcohol dehydrogenases (AAD). Yeast AAD genes are located in subtelomeric regions of different chromosomes, and their functional role(s) remain enigmatic. Here, we show that two of these genes, AAD4 and AAD14 , encode functional enzymes that reduce aliphatic and aryl-aldehydes concomitant with the oxidation of cofactor NADPH, and that Aad4p and Aad14p exhibit different substrate preference patterns. Other yeast AAD genes are undergoing pseudogenization. The 5' sequence of AAD15 has been deleted from the genome. Repair of an AAD3 missense mutation at the catalytically essential Tyr 73 residue did not result in a functional enzyme. However, ancestral-state reconstruction by fusing Aad6 with Aad16 and by N-terminal repair of Aad10 restores NADPH-dependent aryl-alcohol dehydrogenase activities. Phylogenetic analysis indicates that AAD genes are narrowly distributed in wood-saprophyte fungi and in yeast that occupy lignocellulosic niches. Because yeast AAD genes exhibit activity on veratraldehyde, cinnamaldehyde, and vanillin, they could serve to detoxify aryl-aldehydes released during lignin degradation. However, none of these compounds induce yeast AAD gene expression, and Aad activities do not relieve aryl-aldehyde growth inhibition. Our data suggest an ancestral role for AAD genes in lignin degradation that is degenerating as a result of yeast's domestication and use in brewing, baking, and other industrial applications. IMPORTANCE Functional characterization of hypothetical genes remains one of the chief tasks of the postgenomic era. Although the first Saccharomyces cerevisiae genome sequence was published over 20 years ago, 22% of its estimated 6,603 open reading frames (ORFs) remain unverified. One outstanding example of this category of genes is the enigmatic seven-member AAD family. Here, we demonstrate that proteins encoded by two

Overproduction of 2-phenylethanol by industrial yeasts to improve organoleptic properties of bakers' products.

Science.gov (United States)

Dueñas-Sánchez, Rafael; Pérez, Ana G; Codón, Antonio C; Benítez, Tahía; Rincón, Ana María

2014-06-16

2-Phenylethanol (PEA), an important alcohol derived from phenylalanine, is involved in aroma and flavour of bakers' products. Four spontaneous mutants of an industrial bakers' yeast, V1 strain, were isolated for their resistance to p-fluoro-DL-phenylalanine (PFP), a toxic analogue of L-phenylalanine. Mutants overproduced this amino acid and showed variations in their internal pool for several other amino acids. Moreover, a rise in PEA production after growth in industrial medium (MAB) was observed in three of the mutants, although their growth and fermentative capacities were slightly impaired. However, concentration of PEA remained higher during dough fermentation and also after baking, thus improving taste and aroma in bread. Copyright © 2014 Elsevier B.V. All rights reserved.

Impact of Saccharomyces cerevisiae metabolites produced during fermentation on bread quality parameters: A review.

Science.gov (United States)

Heitmann, Mareile; Zannini, Emanuele; Arendt, Elke

2018-05-03

Although bread making with the use of Baker's yeast has a long tradition in human history, little attention has been paid to the connection between yeast addition and the final bread quality. Nowadays, bakers mainly use different flour additives such as enzymes (amylases, hemicellulases, and proteases) to change and improve dough properties and/or bread quality. Another strategy is the use of modified industrial Baker's yeast. To date, there is no yeast strain used in the baking industry, which is genetically modified, despite some studies demonstrating that the application of recombinant DNA technology is a possibility for improved strains suitable for baking. However, due to the fact that the majority of consumers in Europe highly reject the use of genetically modified microorganisms in the production of food, other strategies to improve bread quality must be investigated. Such a strategy would be a reconsideration of the selection of yeast strains used for the baking process. Next to the common criteria, the requirement for adequate gas production, more attention should be paid on how yeast impacts flavor, shelf life, color, and the nutritional value of baked products, in a similar way to which yeast strains are selected in the wine and brewing industries.

Guidelines and recommendations on yeast cell death nomenclature

NARCIS (Netherlands)

Carmona-Gutierrez, Didac; Bauer, Maria Anna; Zimmermann, Andreas; Aguilera, Andrés; Austriaco, Nicanor; Ayscough, Kathryn; Balzan, Rena; Bar-Nun, Shoshana; Barrientos, Antonio; Belenky, Peter; Blondel, Marc; Braun, Ralf J; Breitenbach, Michael; Burhans, William C; Büttner, Sabrina; Cavalieri, Duccio; Chang, Michael; Cooper, Katrina F; Côrte-Real, Manuela; Costa, Vítor; Cullin, Christophe; Dawes, Ian; Dengjel, Jörn; Dickman, Martin B; Eisenberg, Tobias; Fahrenkrog, Birthe; Fasel, Nicolas; Fröhlich, Kai-Uwe; Gargouri, Ali; Giannattasio, Sergio; Goffrini, Paola; Gourlay, Campbell W; Grant, Chris M; Greenwood, Michael T; Guaragnella, Nicoletta; Heger, Thomas; Heinisch, Jürgen; Herker, Eva; Herrmann, Johannes M; Hofer, Sebastian; Jiménez-Ruiz, Antonio; Jungwirth, Helmut; Kainz, Katharina; Kontoyiannis, Dimitrios P; Ludovico, Paula; Manon, Stéphen; Martegani, Enzo; Mazzoni, Cristina; Megeney, Lynn A; Meisinger, Chris; Nielsen, Jens; Nyström, Thomas; Osiewacz, Heinz D; Outeiro, Tiago F; Park, Hay-Oak; Pendl, Tobias; Petranovic, Dina; Picot, Stephane; Polčic, Peter; Powers, Ted; Ramsdale, Mark; Rinnerthaler, Mark; Rockenfeller, Patrick; Ruckenstuhl, Christoph; Schaffrath, Raffael; Segovia, Maria; Severin, Fedor F; Sharon, Amir; Sigrist, Stephan J; Sommer-Ruck, Cornelia; Sousa, Maria João; Thevelein, Johan M; Thevissen, Karin; Titorenko, Vladimir; Toledano, Michel B; Tuite, Mick; Vögtle, F-Nora; Westermann, Benedikt; Winderickx, Joris; Wissing, Silke; Wölfl, Stefan; Zhang, Zhaojie J; Zhao, Richard Y; Zhou, Bing; Galluzzi, Lorenzo; Kroemer, Guido; Madeo, Frank

2018-01-01

Elucidating the biology of yeast in its full complexity has major implications for science, medicine and industry. One of the most critical processes determining yeast life and physiology is cel-lular demise. However, the investigation of yeast cell death is a relatively young field, and a widely

The impact of yeast fermentation on dough matrix properties.

Science.gov (United States)

Rezaei, Mohammad N; Jayaram, Vinay B; Verstrepen, Kevin J; Courtin, Christophe M

2016-08-01

Most studies on dough properties are performed on yeastless dough to exclude the complicating, time-dependent effect of yeast. Baker's yeast, however, impacts dough matrix properties during fermentation, probably through the production of primary (CO2 and ethanol) and secondary (glycerol, acetic acid and succinic acid) metabolites. The aim of this study is to obtain a better understanding of the changes in yeasted dough behavior introduced by fermentation, by investigating the impact of yeast fermentation on Farinograph dough consistency, dough spread, Kieffer rig dough extensibility and gluten agglomeration behavior in a fermented dough-batter gluten starch separation system. Results show that fermentation leads to a dough with less flow and lower extensibility that breaks more easily under stress and strain. The dough showed less elastic and more plastic deformation behavior. Gluten agglomerates were smaller for yeasted dough than for the unyeasted control. These changes probably have to be attributed to metabolites generated during fermentation. Indeed, organic acids and also ethanol in concentrations produced by yeast were previously shown to have similar effects in yeastless dough. These findings imply the high importance of yeast fermentation metabolites on dough matrix properties in industrial bread production. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

Industrial antifoam agents impair ethanol fermentation and induce stress responses in yeast cells.

Science.gov (United States)

Nielsen, Jens Christian; Senne de Oliveira Lino, Felipe; Rasmussen, Thomas Gundelund; Thykær, Jette; Workman, Christopher T; Basso, Thiago Olitta

2017-11-01

The Brazilian sugarcane industry constitutes one of the biggest and most efficient ethanol production processes in the world. Brazilian ethanol production utilizes a unique process, which includes cell recycling, acid wash, and non-aseptic conditions. Process characteristics, such as extensive CO 2 generation, poor quality of raw materials, and frequent contaminations, all lead to excessive foam formation during fermentations, which is treated with antifoam agents (AFA). In this study, we have investigated the impact of industrial AFA treatments on the physiology and transcriptome of the industrial ethanol strain Saccharomyces cerevisiae CAT-1. The investigated AFA included industrially used AFA acquired from Brazilian ethanol plants and commercially available AFA commonly used in the fermentation literature. In batch fermentations, it was shown that industrial AFA compromised growth rates and glucose uptake rates, while commercial AFA had no effect in concentrations relevant for defoaming purposes. Industrial AFA were further tested in laboratory scale simulations of the Brazilian ethanol production process and proved to decrease cell viability compared to the control, and the effects were intensified with increasing AFA concentrations and exposure time. Transcriptome analysis showed that AFA treatments induced additional stress responses in yeast cells compared to the control, shown by an up-regulation of stress-specific genes and a down-regulation of lipid biosynthesis, especially ergosterol. By documenting the detrimental effects associated with chemical AFA, we highlight the importance of developing innocuous systems for foam control in industrial fermentation processes.

Occurrence of Killer Yeast Strains in Fruit and Berry Wine Yeast Populations

Directory of Open Access Journals (Sweden)

Gintare Gulbiniene

2004-01-01

Full Text Available Apple, cranberry, chokeberry and Lithuanian red grape wine yeast populations were used for the determination of killer yeast occurrence. According to the tests of the killer characteristics and immunity the isolated strains were divided into seven groups. In this work the activity of killer toxins purified from some typical strains was evaluated. The analysed strains produced different amounts of active killer toxin and some of them possessed new industrially significant killer properties. Total dsRNA extractions in 11 killer strains of yeast isolated from spontaneous fermentations revealed that the molecular basis of the killer phenomenon was not only dsRNAs, but also unidentified genetic determinants.

Access to Confidential Alcohol Industry Documents: From ‘Big Tobacco’ to ‘Big Booze’

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Ms Laura Bond

2009-03-01

Full Text Available BACKGROUND:Internal tobacco industry document searches have led to the discovery of hitherto unpublisheddocuments that provide insights into the drinks industry. The documents uncover key concerns andstrategies for the drinks industry with focus on the Miller Brewing Company and the Beer Institute.METHODS:The identification of the Philip Morris 1996 CEO Issues Book from the tobacco document archives led to asystematic search for alcohol-related documents. The search was conducted by entering alcohol-relatedterms into search fields of tobacco document archive sites available on the World Wide WebRESULTS:Key areas of concern for the Miller Brewing Company, the Beer Institute, and more broadly, the alcoholindustry include developments of legislative and regulatory controls such as tax increases, advertisingrestrictions and blood alcohol content lowering and public perceptions of harms relating to drunk driving,binge drinking and underage alcohol consumption. Strategies proposed by the Miller Brewing Companyand the Beer Institute to combat these concerns include ally development and maintenance and thepromotion of personal responsibility.CONCLUSIONS:These once confidential internal documents provide new evidence on the drinks industry’s concernsabout possible alcohol control measures and the strategies used to help overcome these concerns. The document findings justify the public health community’s cynicism about the alcohol industry whileproviding a new source of information to assist development in the regulation and control of the drinksindustry.

Brewing as a Comprehensive Learning Platform in Chemical Engineering

Science.gov (United States)

Nielsen, Rudi P.; Sørensen, Jens L.; Simonsen, Morten E.; Madsen, Henrik T.; Muff, Jens; Strandgaard, Morten; Søgaard, Erik G.

2016-01-01

Chemical engineering is mostly taught using traditional classroom teaching and laboratory experiments when possible. Being a wide discipline encompassing topics such as analytical chemistry, process design, and microbiology, it may be argued that brewing of beer has many relations to chemical engineering topic-wise. This work illustrates how…

Industrial relevance of chromosomal copy number variation in Saccharomyces yeasts

NARCIS (Netherlands)

Gorter de Vries, A.R.; Pronk, J.T.; Daran, J.G.

2017-01-01

Chromosomal copy number variation (CCNV) plays a key role in evolution and health of eukaryotes. The unicellular yeast Saccharomyces cerevisiae is an important model for studying the generation, physiological impact, and evolutionary significance of CCNV. Fundamental studies of this yeast have

Effect of Brewing Time and Temperature on the release of ...

African Journals Online (AJOL)

Michael Horsfall

Moringa oleifera blended leaves sample at brewing temperature and time of 29oC and 2mins respectively. ... most countries they are taken as tea to treat diabetics, obesity, fever ... human and highly toxic to insects, making it an ideal.

Impaired Uptake and/or Utilization of Leucine by Saccharomyces cerevisiae Is Suppressed by the SPT15-300 Allele of the TATA-Binding Protein Gene

DEFF Research Database (Denmark)

Baerends, RJ; Qiu, Jin-Long; Rasmussen, Simon

2009-01-01

Successful fermentations to produce ethanol require microbial strains that have a high tolerance to glucose and ethanol. Enhanced glucose/ethanol tolerance of the laboratory yeast Saccharomyces cerevisiae strain BY4741 under certain growth conditions as a consequence of the expression of a dominant...... us to examine the effect of expression of the SPT15-300 allele in various yeast species of industrial importance. Expression of SPT15-300 in leucine-prototrophic strains of S. cerevisiae, Saccharomyces bayanus, or Saccharomyces pastorianus (lager brewing yeast), however, did not improve tolerance...... to ethanol on complex rich medium (yeast extract-peptone-dextrose). The enhanced growth of the laboratory yeast strain BY4741 expressing the SPT15-300 mutant allele was seen only on defined media with low concentrations of leucine, indicating that the apparent improved growth in the presence of ethanol...

Genetics of Yeasts

Science.gov (United States)

Querol, Amparo; Fernández-Espinar, M. Teresa; Belloch, Carmela

The use of yeasts in biotechnology processes dates back to ancient days. Before 7000 BC, beer was produced in Sumeria. Wine was made in Assyria in 3500 BC, and ancient Rome had over 250 bakeries, which were making leavened bread by 100 BC. And milk has been made into Kefyr and Koumiss in Asia for many centuries (Demain, Phaff, & Kurtzman, 1999). However, the importance of yeast in the food and beverage industries was only realized about 1860, when their role in food manufacturing became evident.

Influence of sodium chloride on wine yeast fermentation performance

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Stilianos Logothetis

2010-06-01

Full Text Available Stilianos Logothetis1, Elias T Nerantzis2, Anna Gioulioti3, Tasos Kanelis2, Tataridis Panagiotis2, Graeme Walker11University of Abertay Dundee, School of Contemporary Sciences, Dundee, Scotland; 2TEI of Athens Department of Oenology and Spirit Technology, Biotechnology and Industrial Fermentations Lab Agiou Spiridonos, Athens, Greece; 3Ampeloiniki SA Industrial Park Thermi, Thessaloniki, GreeceAbstract: This paper concerns research into the influence of salt (sodium chloride on growth, viability and fermentation performance in a winemaking strain of the yeast, Saccharomyces cerevisiae. Experimental fermentations were conducted in both laboratory-scale and industrial-scale experiments. Preculturing yeasts in elevated levels of sodium chloride, or salt “preconditioning” led to improved fermentation performance. This was manifest by preconditioned yeasts having an improved capability to ferment high-sugar containing media with increased cell viability and with elevated levels of produced ethanol. Salt-preconditioning most likely influenced the stress-tolerance of yeasts by inducing the synthesis of key metabolites such as trehalose and glycerol. These compounds may act to improve cells’ ability to withstand osmostress and ethanol toxicity during fermentations of grape must. Industrial-scale trials using salt-preconditioned yeasts verified the benefit of this novel physiological cell engineering approach to practical winemaking fermentations.Keywords: salt, preconditioning, fermentation performance, Saccharomyces cerevisiae, wine

Enhancement of the proline and nitric oxide synthetic pathway improves fermentation ability under multiple baking-associated stress conditions in industrial baker's yeast.

Science.gov (United States)

Sasano, Yu; Haitani, Yutaka; Hashida, Keisuke; Ohtsu, Iwao; Shima, Jun; Takagi, Hiroshi

2012-04-01

During the bread-making process, industrial baker's yeast, mostly Saccharomyces cerevisiae, is exposed to baking-associated stresses, such as air-drying and freeze-thaw stress. These baking-associated stresses exert severe injury to yeast cells, mainly due to the generation of reactive oxygen species (ROS), leading to cell death and reduced fermentation ability. Thus, there is a great need for a baker's yeast strain with higher tolerance to baking-associated stresses. Recently, we revealed a novel antioxidative mechanism in a laboratory yeast strain that is involved in stress-induced nitric oxide (NO) synthesis from proline via proline oxidase Put1 and N-acetyltransferase Mpr1. We also found that expression of the proline-feedback inhibition-less sensitive mutant γ-glutamyl kinase (Pro1-I150T) and the thermostable mutant Mpr1-F65L resulted in an enhanced fermentation ability of baker's yeast in bread dough after freeze-thaw stress and air-drying stress, respectively. However, baker's yeast strains with high fermentation ability under multiple baking-associated stresses have not yet been developed. We constructed a self-cloned diploid baker's yeast strain with enhanced proline and NO synthesis by expressing Pro1-I150T and Mpr1-F65L in the presence of functional Put1. The engineered strain increased the intracellular NO level in response to air-drying stress, and the strain was tolerant not only to oxidative stress but also to both air-drying and freeze-thaw stresses probably due to the reduced intracellular ROS level. We also showed that the resultant strain retained higher leavening activity in bread dough after air-drying and freeze-thaw stress than that of the wild-type strain. On the other hand, enhanced stress tolerance and fermentation ability did not occur in the put1-deficient strain. This result suggests that NO is synthesized in baker's yeast from proline in response to oxidative stresses that induce ROS generation and that increased NO plays an important

Enhancement of the proline and nitric oxide synthetic pathway improves fermentation ability under multiple baking-associated stress conditions in industrial baker's yeast

Directory of Open Access Journals (Sweden)

Sasano Yu

2012-04-01

Full Text Available Abstract Background During the bread-making process, industrial baker's yeast, mostly Saccharomyces cerevisiae, is exposed to baking-associated stresses, such as air-drying and freeze-thaw stress. These baking-associated stresses exert severe injury to yeast cells, mainly due to the generation of reactive oxygen species (ROS, leading to cell death and reduced fermentation ability. Thus, there is a great need for a baker's yeast strain with higher tolerance to baking-associated stresses. Recently, we revealed a novel antioxidative mechanism in a laboratory yeast strain that is involved in stress-induced nitric oxide (NO synthesis from proline via proline oxidase Put1 and N-acetyltransferase Mpr1. We also found that expression of the proline-feedback inhibition-less sensitive mutant γ-glutamyl kinase (Pro1-I150T and the thermostable mutant Mpr1-F65L resulted in an enhanced fermentation ability of baker's yeast in bread dough after freeze-thaw stress and air-drying stress, respectively. However, baker's yeast strains with high fermentation ability under multiple baking-associated stresses have not yet been developed. Results We constructed a self-cloned diploid baker's yeast strain with enhanced proline and NO synthesis by expressing Pro1-I150T and Mpr1-F65L in the presence of functional Put1. The engineered strain increased the intracellular NO level in response to air-drying stress, and the strain was tolerant not only to oxidative stress but also to both air-drying and freeze-thaw stresses probably due to the reduced intracellular ROS level. We also showed that the resultant strain retained higher leavening activity in bread dough after air-drying and freeze-thaw stress than that of the wild-type strain. On the other hand, enhanced stress tolerance and fermentation ability did not occur in the put1-deficient strain. This result suggests that NO is synthesized in baker's yeast from proline in response to oxidative stresses that induce ROS

Enhancement of the proline and nitric oxide synthetic pathway improves fermentation ability under multiple baking-associated stress conditions in industrial baker's yeast

Science.gov (United States)

2012-01-01

Background During the bread-making process, industrial baker's yeast, mostly Saccharomyces cerevisiae, is exposed to baking-associated stresses, such as air-drying and freeze-thaw stress. These baking-associated stresses exert severe injury to yeast cells, mainly due to the generation of reactive oxygen species (ROS), leading to cell death and reduced fermentation ability. Thus, there is a great need for a baker's yeast strain with higher tolerance to baking-associated stresses. Recently, we revealed a novel antioxidative mechanism in a laboratory yeast strain that is involved in stress-induced nitric oxide (NO) synthesis from proline via proline oxidase Put1 and N-acetyltransferase Mpr1. We also found that expression of the proline-feedback inhibition-less sensitive mutant γ-glutamyl kinase (Pro1-I150T) and the thermostable mutant Mpr1-F65L resulted in an enhanced fermentation ability of baker's yeast in bread dough after freeze-thaw stress and air-drying stress, respectively. However, baker's yeast strains with high fermentation ability under multiple baking-associated stresses have not yet been developed. Results We constructed a self-cloned diploid baker's yeast strain with enhanced proline and NO synthesis by expressing Pro1-I150T and Mpr1-F65L in the presence of functional Put1. The engineered strain increased the intracellular NO level in response to air-drying stress, and the strain was tolerant not only to oxidative stress but also to both air-drying and freeze-thaw stresses probably due to the reduced intracellular ROS level. We also showed that the resultant strain retained higher leavening activity in bread dough after air-drying and freeze-thaw stress than that of the wild-type strain. On the other hand, enhanced stress tolerance and fermentation ability did not occur in the put1-deficient strain. This result suggests that NO is synthesized in baker's yeast from proline in response to oxidative stresses that induce ROS generation and that increased NO

Yeast cell differentiation: Lessons from pathogenic and non-pathogenic yeasts.

Science.gov (United States)

Palková, Zdena; Váchová, Libuše

2016-09-01

Yeasts, historically considered to be single-cell organisms, are able to activate different differentiation processes. Individual yeast cells can change their life-styles by processes of phenotypic switching such as the switch from yeast-shaped cells to filamentous cells (pseudohyphae or true hyphae) and the transition among opaque, white and gray cell-types. Yeasts can also create organized multicellular structures such as colonies and biofilms, and the latter are often observed as contaminants on surfaces in industry and medical care and are formed during infections of the human body. Multicellular structures are formed mostly of stationary-phase or slow-growing cells that diversify into specific cell subpopulations that have unique metabolic properties and can fulfill specific tasks. In addition to the development of multiple protective mechanisms, processes of metabolic reprogramming that reflect a changed environment help differentiated individual cells and/or community cell constituents to survive harmful environmental attacks and/or to escape the host immune system. This review aims to provide an overview of differentiation processes so far identified in individual yeast cells as well as in multicellular communities of yeast pathogens of the Candida and Cryptococcus spp. and the Candida albicans close relative, Saccharomyces cerevisiae. Molecular mechanisms and extracellular signals potentially involved in differentiation processes are also briefly mentioned. Copyright © 2016 Elsevier Ltd. All rights reserved.

A xylanase with broad pH and temperature adaptability from Streptomyces megasporus DSM 41476, and its potential application in brewing industry.

Science.gov (United States)

Qiu, Zhenhua; Shi, Pengjun; Luo, Huiying; Bai, Yingguo; Yuan, Tiezheng; Yang, Peilong; Liu, Suchun; Yao, Bin

2010-05-05

A xylanase gene, xynAM6, was isolated from the genomic DNA library of Streptomyces megasporus DSM 41476 using colony PCR screening method. The 1440-bp full-length gene encodes a 479-amino acid peptide consisting of a putative signal peptide of 36 residues, a family 10 glycoside hydrolase domain and a family 2 carbohydrate-binding module. The mature peptide of xynAM6 was successfully expressed in Pichia pastoris GS115. The optimal pH and temperature were pH 5.5 and 70°C, respectively. The enzyme showed broad temperature adaptability (>60% of the maximum activity at 50-80°C), had good thermostability at 60°C and 70°C, remained stable at pH 4.0-11.0, and was resistant to most proteases. The Km and Vmax values for oat spelt xylan were 1.68mgml(-1) and 436.76μmolmin(-1)mg(-1), respectively, and 2.33mgml(-1) and 406.93μmolmin(-1)mg(-1) for birchwood xylan, respectively. The hydrolysis products of XYNAM6 were mainly xylose and xylobiose. Addition of XYNAM6 (80U) to the brewery mash significantly reduced the filtration rate and viscosity by 36.33% and 35.51%, respectively. These favorable properties probably make XYNAM6 a good candidate for application in brewing industry. Copyright © 2010 Elsevier Inc. All rights reserved.

Signature gene expressions of cell wall integrity pathway concur with tolerance response of industrial yeast Saccharomyces cerevisiae against biomass pretreatment inhibitors

Science.gov (United States)

Traditional industrial ethanologenic yeast Saccharomyces cerevisiae has a robust performance under various environmental conditions and can be served as a candidate for the next-generation biocatalyst development for advanced biofuels production using lignocellulose mateials. Overcoming toxic compou...

Production of fermentation aroma compounds by Saccharomyces cerevisiae wine yeasts: effects of yeast assimilable nitrogen on two model strains.

Science.gov (United States)

Carrau, Francisco M; Medina, Karina; Farina, Laura; Boido, Eduardo; Henschke, Paul A; Dellacassa, Eduardo

2008-11-01

The contribution of yeast fermentation metabolites to the aromatic profile of wine is well documented; however, the biotechnological application of this knowledge, apart from strain selection, is still rather limited and often contradictory. Understanding and modeling the relationship between nutrient availability and the production of desirable aroma compounds by different strains must be one of the main objectives in the selection of industrial yeasts for the beverage and food industry. In order to overcome the variability in the composition of grape juices, we have used a chemically defined model medium for studying yeast physiological behavior and metabolite production in response to nitrogen supplementation so as to identify an appropriate yeast assimilable nitrogen level for strain differentiation. At low initial nitrogen concentrations, strain KU1 produced higher quantities of esters and fatty acids whereas M522 produced higher concentrations of isoacids, gamma-butyrolactone, higher alcohols and 3-methylthio-1-propanol. We propose that although strains KU1 and M522 have a similar nitrogen consumption profile, they represent useful models for the chemical characterization of wine strains in relation to wine quality. The differential production of aroma compounds by the two strains is discussed in relation to their capacity for nitrogen usage and their impact on winemaking. The results obtained here will help to develop targeted metabolic footprinting methods for the discrimination of industrial yeasts.

Comparison of analytical parameters of beer brewed in two different technological ways at two pub breweries

Directory of Open Access Journals (Sweden)

Pavel Kryl

2012-01-01

Full Text Available This publication deals with brewing beer by infusion and decoction technologies of mash production in microbreweries. Samples of two microbrewery beers are compared, namely Richard beer (Brno-Žebětín produced in a double mash manner appropriate for the Czech brewing type, and beer samples taken at the laboratory microbrewery of Mendel University in Brno (MENDELU, where beer is produced in a simpler and less energy – demanding infusion method. At all the beer samples the basic analytical parameters of real extract, ethanol content, degree of fermentation and the extract of original hopped wort were measured using an automatic beer analyzer. The results coming out of the automatic beer analyzer are compared with the results of the beer samples analysis performed by liquid chromatography, by which the contents of oligosaccharides, maltose, glycerol and ethanol were measured. Both methods provide a number of analytical results for the comparison of decoction and infusion techniques, and analytical characteristics of both the brewing procedures. Emphasis is placed on statistical data processing and comparison of different types of beer and particular brews between each other, both in terms of production technology as well as beer sampling throughout the year.

Innovation Chinese rice wine brewing technology by bi-acidification to exclude rice soaking process.

Science.gov (United States)

Wei, Xiao Lu; Liu, Shuang Ping; Yu, Jian Shen; Yu, Yong Jian; Zhu, Sheng Hu; Zhou, Zhi Lei; Hu, Jian; Mao, Jian

2017-04-01

As a traditional fermented alcoholic beverage of China, Chinese rice wine (CRW) had a long history of more than 5000 years. Rice soaking process was the most crucial step during CRW brewing process, because rice soaking quality directly determined the quality of CRW. However, rice soaking water would cause the eutrophication of water bodies and waste of water. The longer time of rice soaking, the higher the content of biogenic amine, and it would have a huge impact on human health. An innovation brewing technology was carried out to exclude the rice soaking process and the Lactobacillus was added to make up for the total acid. Compared to the traditional brewing technology, the new technology saved water resources and reduced environmental pollution. The concentration of biogenic amine was also decreased by 27.16%, which improving the security of the CRW. The esters increased led to more soft-tasted CRW and less aging time; the quality of CRW would be improved with less alcohol. Copyright © 2016 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Yeast selection for fuel ethanol production in Brazil.

Science.gov (United States)

Basso, Luiz C; de Amorim, Henrique V; de Oliveira, Antonio J; Lopes, Mario L

2008-11-01

Brazil is one of the largest ethanol biofuel producers and exporters in the world and its production has increased steadily during the last three decades. The increasing efficiency of Brazilian ethanol plants has been evident due to the many technological contributions. As far as yeast is concerned, few publications are available regarding the industrial fermentation processes in Brazil. The present paper reports on a yeast selection program performed during the last 12 years aimed at selecting Saccharomyces cerevisiae strains suitable for fermentation of sugar cane substrates (cane juice and molasses) with cell recycle, as it is conducted in Brazilian bioethanol plants. As a result, some evidence is presented showing the positive impact of selected yeast strains in increasing ethanol yield and reducing production costs, due to their higher fermentation performance (high ethanol yield, reduced glycerol and foam formation, maintenance of high viability during recycling and very high implantation capability into industrial fermenters). Results also suggest that the great yeast biodiversity found in distillery environments could be an important source of strains. This is because during yeast cell recycling, selective pressure (an adaptive evolution) is imposed on cells, leading to strains with higher tolerance to the stressful conditions of the industrial fermentation.

[Distiller Yeasts Producing Antibacterial Peptides].

Science.gov (United States)

Klyachko, E V; Morozkina, E V; Zaitchik, B Ts; Benevolensky, S V

2015-01-01

A new method of controlling lactic acid bacteria contamination was developed with the use of recombinant Saccharomyces cerevisiae strains producing antibacterial peptides. Genes encoding the antibacterial peptides pediocin and plantaricin with codons preferable for S. cerevisiae were synthesized, and a system was constructed for their secretory expression. Recombinant S. cerevisiae strains producing antibacterial peptides effectively inhibit the growth of Lactobacillus sakei, Pediacoccus pentasaceus, Pediacoccus acidilactici, etc. The application of distiller yeasts producing antibacterial peptides enhances the ethanol yield in cases of bacterial contamination. Recombinant yeasts producing the antibacterial peptides pediocin and plantaricin can successfully substitute the available industrial yeast strains upon ethanol production.

The Biology and Chemistry of Brewing: An Interdisciplinary Course

Science.gov (United States)

Hooker, Paul D.; Deutschman, William A.; Avery, Brian J.

2014-01-01

For the past nine years, we have been offering an interdisciplinary course for science majors: The Biology and Chemistry of Brewing. This course is primarily laboratory- and inquiry-based; from a total of 24 h of student/instructor contact time, approximately 6 h are devoted to lecture, and the other 18 h are divided between laboratory exercises,…

Guidelines and recommendations on yeast cell death nomenclature

OpenAIRE

Carmona-Gutierrez, Didac; Bauer, Maria Anna; Zimmermann, Andreas; Aguilera, Andres; Austriaco, Nicanor; Sigrist, Stephan J.

2018-01-01

Elucidating the biology of yeast in its full complexity has major implications for science, medicine and industry. One of the most critical processes determining yeast life and physiology is cellular demise. However, the investigation of yeast cell death is a relatively young field, and a widely accepted set of concepts and terms is still missing. Here, we propose unified criteria for the definition of accidental, regulated, and programmed forms of cell death in yeast based on a series of mor...

Heuristic Sensitivity Analysis for Baker's Yeast Model Parameters

OpenAIRE

Leão, Celina P.; Soares, Filomena O.

2004-01-01

The baker's yeast, essentially composed by living cells of Saccharomyces cerevisiae, used in the bread making and beer industries as a microorganism, has an important industrial role. The simulation procedure represents then a necessary tool to understand clearly the baker's yeast fermentation process. The use of mathematical models based on mass balance equations requires the knowledge of the reaction kinetics, thermodynamics, and transport and physical properties. Models may be more or less...

How do yeast cells become tolerant to high ethanol concentrations?

DEFF Research Database (Denmark)

Snoek, Tim; Verstrepen, Kevin J.; Voordeckers, Karin

2016-01-01

The brewer’s yeast Saccharomyces cerevisiae displays a much higher ethanol tolerance compared to most other organisms, and it is therefore commonly used for the industrial production of bioethanol and alcoholic beverages. However, the genetic determinants underlying this yeast’s exceptional ethanol...... and challenges involved in obtaining superior industrial yeasts with improved ethanol tolerance....

Saccharomyces species in the Production of Beer

Directory of Open Access Journals (Sweden)

Graham G. Stewart

2016-12-01

Full Text Available The characteristic flavour and aroma of any beer is, in large part, determined by the yeast strain employed and the wort composition. In addition, properties such as flocculation, wort fermentation ability (including the uptake of wort sugars, amino acids, and peptides, ethanol and osmotic pressure tolerance together with oxygen requirements have a critical impact on fermentation performance. Yeast management between fermentations is also a critical brewing parameter. Brewer’s yeasts are mostly part of the genus Saccharomyces. Ale yeasts belong to the species Saccharomyces cerevisiae and lager yeasts to the species Saccharomyces pastorianus. The latter is an interspecies hybrid between S. cerevisiae and Saccharomyces eubayanus. Brewer’s yeast strains are facultative anaerobes—they are able to grow in the presence or absence of oxygen and this ability supports their property as an important industrial microorganism. This article covers important aspects of Saccharomyces molecular biology, physiology, and metabolism that is involved in wort fermentation and beer production.

Use of whey lactose from dairy industry for economical kefiran production by Lactobacillus kefiranofaciens in mixed cultures with yeasts.

Science.gov (United States)

Cheirsilp, Benjamas; Radchabut, Sirilaor

2011-10-01

To evaluate the feasibility of producing kefiran industrially, whey lactose, a by-product from dairy industry, was used as a low cost carbon source. Because the accumulation of lactic acid as a by-product of Lactobacillus kefiranofaciens inhibited cell growth and kefiran production, the kefir grain derived and non-derived yeasts were screened for their abilities to reduce lactic acid and promote kefiran production in a mixed culture. Six species of yeasts were examined: Torulaspora delbrueckii IFO 1626; Saccharomyces cerevisiae IFO 0216; Debaryomyces hansenii TISTR 5155; Saccharomyces exiguus TISTR 5081; Zygosaccharomyces rouxii TISTR 5044; and Saccharomyces carlsbergensis TISTR 5018. The mixed culture of L. kefiranofaciens with S. cerevisiae IFO 0216 enhanced the kefiran production best from 568 mg/L in the pure culture up to 807 and 938 mg/L in the mixed cultures under anaerobic and microaerobic conditions, respectively. The optimal conditions for kefiran production by the mixed culture were: whey lactose 4%; yeast extract 4%; initial pH of 5.5; and initial amounts of L. kefiranofaciens and S. cerevisiae IFO 0216 of 2.1×10(7) and 4.0×10(6)CFU/mL, respectively. Scaling up the mixed culture in a 2L bioreactor with dissolved oxygen control at 5% and pH control at 5.5 gave the maximum kefiran production of 2,580 mg/L in batch culture and 3,250 mg/L in fed-batch culture. Copyright © 2011 Elsevier B.V. All rights reserved.

The fungicide triadimefon affects beer flavor and composition by influencing Saccharomyces cerevisiae metabolism

Science.gov (United States)

Kong, Zhiqiang; Li, Minmin; An, Jingjing; Chen, Jieying; Bao, Yuming; Francis, Frédéric; Dai, Xiaofeng

2016-09-01

Despite the fact that beer is produced on a large scale, the effects of pesticide residues on beer have been rarely investigated. In this study, we used micro-brewing settings to determine the effect of triadimefon on the growth of Saccharomyces cerevisiae and beer flavor. The yeast growth in medium was significantly inhibited (45%) at concentrations higher than 5 mg L-1, reaching 80% and 100% inhibition at 10 mg L-1 and 50 mg L-1, respectively. There were significant differences in sensory quality between beer samples fermented with and without triadimefon based on data obtained with an electronic tongue and nose. Such an effect was most likely underlain by changes in yeast fermentation activity, including decreased utilization of maltotriose and most amino acids, reduced production of isobutyl and isoamyl alcohols, and increased ethyl acetate content in the fungicide treated samples. Furthermore, yeast metabolic profiling by phenotype microarray and UPLC/TOF-MS showed that triadimefon caused significant changes in the metabolism of glutathione, phenylalanine and sphingolipids, and in sterol biosynthesis. Thus, triadimefon negatively affects beer sensory qualities by influencing the metabolic activity of S. cerevisiae during fermentation, emphasizing the necessity of stricter control over fungicide residues in brewing by the food industry.

Yeast cell factories on the horizon

DEFF Research Database (Denmark)

Nielsen, Jens

2015-01-01

For thousands of years, yeast has been used for making beer, bread, and wine. In modern times, it has become a commercial workhorse for producing fuels, chemicals, and pharmaceuticals such as insulin, human serum albumin, and vaccines against hepatitis virus and human papillomavirus. Yeast has also...... been engineered to make chemicals at industrial scale (e.g., succinic acid, lactic acid, resveratrol) and advanced biofuels (e.g., isobutanol) (1). On page 1095 of this issue, Galanie et al. (2) demonstrate that yeast can now be engineered to produce opioids (2), a major class of compounds used...

Construction of a highly thermostable 1,3-1,4-β-glucanase by combinational mutagenesis and its potential application in the brewing industry.

Science.gov (United States)

Niu, Chengtuo; Zhu, Linjiang; Hill, Annie; Alex Speers, R; Li, Qi

2017-01-01

To improve the thermostability and catalytic property of a mesophilic 1,3-1,4-β-glucanase by combinational mutagenesis and to test its effect in congress mashing. A mutant β-glucanase (rE-BglTO) constructed by combinational mutagenesis showed a 25 °C increase in optimal temperature (to 70 °C) a 19.5 °C rise in T 50 value and a 15.6 °C increase in melting temperature compared to wild-type enzyme. Its half-life values at 60 and 70 °C were 152 and 99 min, which were 370 and 800 % higher than those of wild-type enzyme. Besides, its specific activity and k cat value were 42,734 U mg -1 and 189 s -1 while its stability under acidic conditions was also improved. In flask fermentation, the catalytic activity of rE-BglTO reached 2381 U ml -1 , which was 63 % higher than that of wild-type enzyme. The addition of rE-BglTO in congress mashing decreased the filtration time and viscosity by 21.3 and 9.6 %, respectively. The mutant β-glucanase showed high catalytic activity and thermostability which indicated that rE-BglTO is a good candidate for application in the brewing industry.

The use of lactic acid-producing, malic acid-producing, or malic acid-degrading yeast strains for acidity adjustment in the wine industry.

Science.gov (United States)

Su, Jing; Wang, Tao; Wang, Yun; Li, Ying-Ying; Li, Hua

2014-03-01

In an era of economic globalization, the competition among wine businesses is likely to get tougher. Biotechnological innovation permeates the entire world and intensifies the severity of the competition of the wine industry. Moreover, modern consumers preferred individualized, tailored, and healthy and top quality wine products. Consequently, these two facts induce large gaps between wine production and wine consumption. Market-orientated yeast strains are presently being selected or developed for enhancing the core competitiveness of wine enterprises. Reasonable biological acidity is critical to warrant a high-quality wine. Many wild-type acidity adjustment yeast strains have been selected all over the world. Moreover, mutation breeding, metabolic engineering, genetic engineering, and protoplast fusion methods are used to construct new acidity adjustment yeast strains to meet the demands of the market. In this paper, strategies and concepts for strain selection or improvement methods were discussed, and many examples based upon selected studies involving acidity adjustment yeast strains were reviewed. Furthermore, the development of acidity adjustment yeast strains with minimized resource inputs, improved fermentation, and enological capabilities for an environmentally friendly production of healthy, top quality wine is presented.

History of genome editing in yeast.

Science.gov (United States)

Fraczek, Marcin G; Naseeb, Samina; Delneri, Daniela

2018-05-01

For thousands of years humans have used the budding yeast Saccharomyces cerevisiae for the production of bread and alcohol; however, in the last 30-40 years our understanding of the yeast biology has dramatically increased, enabling us to modify its genome. Although S. cerevisiae has been the main focus of many research groups, other non-conventional yeasts have also been studied and exploited for biotechnological purposes. Our experiments and knowledge have evolved from recombination to high-throughput PCR-based transformations to highly accurate CRISPR methods in order to alter yeast traits for either research or industrial purposes. Since the release of the genome sequence of S. cerevisiae in 1996, the precise and targeted genome editing has increased significantly. In this 'Budding topic' we discuss the significant developments of genome editing in yeast, mainly focusing on Cre-loxP mediated recombination, delitto perfetto and CRISPR/Cas. © 2018 The Authors. Yeast published by John Wiley & Sons, Ltd.

Advances in metabolic engineering of yeast Saccharomyces cerevisiae for production of chemicals.

Science.gov (United States)

Borodina, Irina; Nielsen, Jens

2014-05-01

Yeast Saccharomyces cerevisiae is an important industrial host for production of enzymes, pharmaceutical and nutraceutical ingredients and recently also commodity chemicals and biofuels. Here, we review the advances in modeling and synthetic biology tools and how these tools can speed up the development of yeast cell factories. We also present an overview of metabolic engineering strategies for developing yeast strains for production of polymer monomers: lactic, succinic, and cis,cis-muconic acids. S. cerevisiae has already firmly established itself as a cell factory in industrial biotechnology and the advances in yeast strain engineering will stimulate development of novel yeast-based processes for chemicals production. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Malting and Brewing Industries Encounter Fusarium spp. Related Problems

Directory of Open Access Journals (Sweden)

Kristina Mastanjević

2018-01-01

Full Text Available Versatile microbiota are inevitably naturally present on cereals. Fungi, yeasts and bacteria and their metabolites all contribute to the quality and safety of the final products derived from most common beer cereals—barley and wheat. The microorganisms that are most often associated with the safety and quality of cereals for beer production belong to the Fusarium spp. They greatly influence yields from the field, and can modify and diminish economic success for farmers. However, the real problem is their harmful metabolites—mycotoxins—that affect the health of humans and animals. In the era of emerging analytical methodologies, the spectrum of known toxins originating from microorganisms that can pose a threat to humans has grown tremendously. Therefore, it is necessary to monitor microflora throughout the productive “barley to beer” chain and to act suppressive on the proliferation of unwanted microorganisms, before and during malting, preventing the occurrence of mycotoxins in final products and by-products. Multi-mycotoxin analyses are very advanced and useful tools for the assessment of product safety, and legislation should follow up and make some important changes to regulate as yet unregulated, but highly occurring, microbial toxins in malt and beer.

Nitrile Metabolizing Yeasts

Science.gov (United States)

Bhalla, Tek Chand; Sharma, Monica; Sharma, Nitya Nand

Nitriles and amides are widely distributed in the biotic and abiotic components of our ecosystem. Nitrile form an important group of organic compounds which find their applications in the synthesis of a large number of compounds used as/in pharmaceutical, cosmetics, plastics, dyes, etc>. Nitriles are mainly hydro-lyzed to corresponding amide/acid in organic chemistry. Industrial and agricultural activities have also lead to release of nitriles and amides into the environment and some of them pose threat to human health. Biocatalysis and biotransformations are increasingly replacing chemical routes of synthesis in organic chemistry as a part of ‘green chemistry’. Nitrile metabolizing organisms or enzymes thus has assumed greater significance in all these years to convert nitriles to amides/ acids. The nitrile metabolizing enzymes are widely present in bacteria, fungi and yeasts. Yeasts metabolize nitriles through nitrilase and/or nitrile hydratase and amidase enzymes. Only few yeasts have been reported to possess aldoxime dehydratase. More than sixty nitrile metabolizing yeast strains have been hither to isolated from cyanide treatment bioreactor, fermented foods and soil. Most of the yeasts contain nitrile hydratase-amidase system for metabolizing nitriles. Transformations of nitriles to amides/acids have been carried out with free and immobilized yeast cells. The nitrilases of Torulopsis candida>and Exophiala oligosperma>R1 are enantioselec-tive and regiospecific respectively. Geotrichum>sp. JR1 grows in the presence of 2M acetonitrile and may have potential for application in bioremediation of nitrile contaminated soil/water. The nitrilase of E. oligosperma>R1 being active at low pH (3-6) has shown promise for the hydroxy acids. Immobilized yeast cells hydrolyze some additional nitriles in comparison to free cells. It is expected that more focus in future will be on purification, characterization, cloning, expression and immobilization of nitrile metabolizing

Effect of salt hyperosmotic stress on yeast cell viability

Directory of Open Access Journals (Sweden)

Logothetis Stelios

2007-01-01

Full Text Available During fermentation for ethanol production, yeasts are subjected to different kinds of physico-chemical stresses such as: initially high sugar concentration and low temperature; and later, increased ethanol concentrations. Such conditions trigger a series of biological responses in an effort to maintain cell cycle progress and yeast cell viability. Regarding osmostress, many studies have been focused on transcriptional activation and gene expression in laboratory strains of Saccharomyces cerevisiae. The overall aim of this present work was to further our understanding of wine yeast performance during fermentations under osmotic stress conditions. Specifically, the research work focused on the evaluation of NaCl-induced stress responses of an industrial wine yeast strain S. cerevisiae (VIN 13, particularly with regard to yeast cell growth and viability. The hypothesis was that osmostress conditions energized specific genes to enable yeast cells to survive under stressful conditions. Experiments were designed by pretreating cells with different sodium chloride concentrations (NaCl: 4%, 6% and 10% w/v growing in defined media containing D-glucose and evaluating the impact of this on yeast growth and viability. Subsequent fermentation cycles took place with increasing concentrations of D-glucose (20%, 30%, 40% w/v using salt-adapted cells as inocula. We present evidence that osmostress induced by mild salt pre-treatments resulted in beneficial influences on both cell viability and fermentation performance of an industrial wine yeast strain.

Advances in metabolic engineering of yeast Saccharomyces cerevisiae for production of chemicals

DEFF Research Database (Denmark)

Borodina, Irina; Nielsen, Jens

2014-01-01

Yeast Saccharomyces cerevisiae is an important industrial host for production of enzymes, pharmaceutical and nutraceutical ingredients and recently also commodity chemicals and biofuels. Here, we review the advances in modeling and synthetic biology tools and how these tools can speed up the deve......Yeast Saccharomyces cerevisiae is an important industrial host for production of enzymes, pharmaceutical and nutraceutical ingredients and recently also commodity chemicals and biofuels. Here, we review the advances in modeling and synthetic biology tools and how these tools can speed up...... the development of yeast cell factories. We also present an overview of metabolic engineering strategies for developing yeast strains for production of polymer monomers: lactic, succinic, and cis,cis-muconic acids. S. cerevisiae has already firmly established itself as a cell factory in industrial biotechnology...

Advertising and concentration in the brewing industry

DEFF Research Database (Denmark)

Madsen, Erik Strøjer; Wu, Yanqing

The opening of the markets in East Asia and Eastern Europe in the 1990s changed the structure of the beer markets and in the following years a large wave of mergers and acquisitions took place. The paper tracks the development in industry concentrations from 2002 to 2012, discusses some of the main...... drivers behind this development and points to economies of scale in advertising as a main pay-off from mergers and acquisitions. Using firm-level data both from the American market and the world market, the estimations verify significant economies of scale in marketing and distribution costs. Based...

Metabolic engineering of yeast for lignocellulosic biofuel production.

Science.gov (United States)

Jin, Yong-Su; Cate, Jamie Hd

2017-12-01

Production of biofuels from lignocellulosic biomass remains an unsolved challenge in industrial biotechnology. Efforts to use yeast for conversion face the question of which host organism to use, counterbalancing the ease of genetic manipulation with the promise of robust industrial phenotypes. Saccharomyces cerevisiae remains the premier host for metabolic engineering of biofuel pathways, due to its many genetic, systems and synthetic biology tools. Numerous engineering strategies for expanding substrate ranges and diversifying products of S. cerevisiae have been developed. Other yeasts generally lack these tools, yet harbor superior phenotypes that could be exploited in the harsh processes required for lignocellulosic biofuel production. These include thermotolerance, resistance to toxic compounds generated during plant biomass deconstruction, and wider carbon consumption capabilities. Although promising, these yeasts have yet to be widely exploited. By contrast, oleaginous yeasts such as Yarrowia lipolytica capable of producing high titers of lipids are rapidly advancing in terms of the tools available for their metabolic manipulation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Polyhexamethyl biguanide can eliminate contaminant yeasts from fuel-ethanol fermentation process.

Science.gov (United States)

Elsztein, Carolina; de Menezes, João Assis Scavuzzi; de Morais, Marcos Antonio

2008-09-01

Industrial ethanol fermentation is a non-sterile process and contaminant microorganisms can lead to a decrease in industrial productivity and significant economic loss. Nowadays, some distilleries in Northeastern Brazil deal with bacterial contamination by decreasing must pH and adding bactericides. Alternatively, contamination can be challenged by adding a pure batch of Saccharomyces cerevisiae-a time-consuming and costly process. A better strategy might involve the development of a fungicide that kills contaminant yeasts while preserving S. cerevisiae cells. Here, we show that polyhexamethyl biguanide (PHMB) inhibits and kills the most important contaminant yeasts detected in the distilleries of Northeastern Brazil without affecting the cell viability and fermentation capacity of S. cerevisiae. Moreover, some physiological data suggest that PHMB acts through interaction with the yeast membrane. These results support the development of a new strategy for controlling contaminant yeast population whilst keeping industrial yields high.

CONCERNING THE HYGIENIC STUDY OF ENZYME PREPARATIONS PRODUCED BY MICROFUNGI AND THEIR POSSIBLE USE IN THE FOOD INDUSTRY

Science.gov (United States)

Conclusions: (1) Large doses of enzyme preparations of the fungi Trichothecium roseum, Aspergillus oryzae strain No. 476I, and Aspergillus awamori...extensive industrial testing in the brewing industry, as well as enzyme preparations of the fungi Aspergillus oryzae strain No. 476I and Aspergillus

Filtration, haze and foam characteristics of fermented wort mediated by yeast strain.

Science.gov (United States)

Douglas, P; Meneses, F J; Jiranek, V

2006-01-01

To investigate the influence of the choice of yeast strain on the haze, shelf life, filterability and foam quality characteristics of fermented products. Twelve strains were used to ferment a chemically defined wort and hopped ale or stout wort. Fermented products were assessed for foam using the Rudin apparatus, and filterability and haze characteristics using the European Brewing Convention methods, to reveal differences in these parameters as a consequence of the choice of yeast strain and growth medium. Under the conditions used, the choice of strain of Saccharomyces cerevisiae effecting the primary fermentation has an impact on all of the parameters investigated, most notably when the fermentation medium is devoid of macromolecular material. The filtration of fermented products has a large cost implication for many brewers and wine makers, and the haze of the resulting filtrate is a key quality criterion. Also of importance to the quality of beer and some wines is the foaming and head retention of these beverages. The foam characteristics, filterability and potential for haze formation in a fermented product have long been known to be dependant on the raw materials used, as well as other production parameters. The choice of Saccharomyces cerevisiae strain used to ferment has itself been shown here to influence these parameters.

Selenium in commercial beer and losses in the brewing process from wheat to beer.

Science.gov (United States)

Rodrigo, S; Young, S D; Cook, D; Wilkinson, S; Clegg, S; Bailey, E H; Mathers, A W; Broadley, M R

2015-09-01

There is increasing interest in enhancing the micronutrient composition of cereals through fertilization. The aims of this study were (1) to determine the Se concentration of commercial beers retailing in the UK, and (2) to test if the transfer of Se, from biofortified grain to final beer product, is brewing trials with isotopically-enriched (77)Se wheat, sampled from UK field-sites, showed that most (77)Se losses in the brewing process occurred during mashing (54%), with fermented beer containing ∼ 10% of the (77)Se initially present in the wheat grain. Total N values in wort and malt were positively correlated with the (77)Se content of the wheat grain. Copyright © 2015 Elsevier Ltd. All rights reserved.

YMDB: the Yeast Metabolome Database

Science.gov (United States)

Jewison, Timothy; Knox, Craig; Neveu, Vanessa; Djoumbou, Yannick; Guo, An Chi; Lee, Jacqueline; Liu, Philip; Mandal, Rupasri; Krishnamurthy, Ram; Sinelnikov, Igor; Wilson, Michael; Wishart, David S.

2012-01-01

The Yeast Metabolome Database (YMDB, http://www.ymdb.ca) is a richly annotated ‘metabolomic’ database containing detailed information about the metabolome of Saccharomyces cerevisiae. Modeled closely after the Human Metabolome Database, the YMDB contains >2000 metabolites with links to 995 different genes/proteins, including enzymes and transporters. The information in YMDB has been gathered from hundreds of books, journal articles and electronic databases. In addition to its comprehensive literature-derived data, the YMDB also contains an extensive collection of experimental intracellular and extracellular metabolite concentration data compiled from detailed Mass Spectrometry (MS) and Nuclear Magnetic Resonance (NMR) metabolomic analyses performed in our lab. This is further supplemented with thousands of NMR and MS spectra collected on pure, reference yeast metabolites. Each metabolite entry in the YMDB contains an average of 80 separate data fields including comprehensive compound description, names and synonyms, structural information, physico-chemical data, reference NMR and MS spectra, intracellular/extracellular concentrations, growth conditions and substrates, pathway information, enzyme data, gene/protein sequence data, as well as numerous hyperlinks to images, references and other public databases. Extensive searching, relational querying and data browsing tools are also provided that support text, chemical structure, spectral, molecular weight and gene/protein sequence queries. Because of S. cervesiae's importance as a model organism for biologists and as a biofactory for industry, we believe this kind of database could have considerable appeal not only to metabolomics researchers, but also to yeast biologists, systems biologists, the industrial fermentation industry, as well as the beer, wine and spirit industry. PMID:22064855

Yeast synthetic biology toolbox and applications for biofuel production.

Science.gov (United States)

Tsai, Ching-Sung; Kwak, Suryang; Turner, Timothy L; Jin, Yong-Su

2015-02-01

Yeasts are efficient biofuel producers with numerous advantages outcompeting bacterial counterparts. While most synthetic biology tools have been developed and customized for bacteria especially for Escherichia coli, yeast synthetic biological tools have been exploited for improving yeast to produce fuels and chemicals from renewable biomass. Here we review the current status of synthetic biological tools and their applications for biofuel production, focusing on the model strain Saccharomyces cerevisiae We describe assembly techniques that have been developed for constructing genes, pathways, and genomes in yeast. Moreover, we discuss synthetic parts for allowing precise control of gene expression at both transcriptional and translational levels. Applications of these synthetic biological approaches have led to identification of effective gene targets that are responsible for desirable traits, such as cellulosic sugar utilization, advanced biofuel production, and enhanced tolerance against toxic products for biofuel production from renewable biomass. Although an array of synthetic biology tools and devices are available, we observed some gaps existing in tool development to achieve industrial utilization. Looking forward, future tool development should focus on industrial cultivation conditions utilizing industrial strains. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permission@oup.com.

Yeast Cell Factory-Platform for the Screening and the Industrial Production of Flavonoids and other Phenolic Compounds

DEFF Research Database (Denmark)

Lehka, Beata Joanna

Flavonoids are secondary plant metabolites derived from the phenylpropanoid pathway. These bioactive compounds are of great commercial interest due to their varied properties, such as anti-oxidative, anti-tumor and/or antibacterial. However, industrial production of flavonoids based on purification...... as a model for industrial production of flavonoids. By combining a balanced heterologous expression of (phenylpropanoid) naringenin biosynthetic pathway genes and the optimisation of yeast metabolism we developed a strain producing 430 mg/L of naringenin from glucose. In this set up naringenin was produced...... from Aeromonas salmonicida with relatively high activity towards tyrosine and no activity towards phenylalanine. Production of flavonoids and stilbenoids in S. cerevisiae is challenging, partially due to carbon loss towards phloretic acid by the action of an unknown endogenous reductase. Through...

Yeast derived from lignocellulosic biomass as a sustainable feed resource for use in aquaculture.

Science.gov (United States)

Øverland, Margareth; Skrede, Anders

2017-02-01

The global expansion in aquaculture production implies an emerging need of suitable and sustainable protein sources. Currently, the fish feed industry is dependent on high-quality protein sources of marine and plant origin. Yeast derived from processing of low-value and non-food lignocellulosic biomass is a potential sustainable source of protein in fish diets. Following enzymatic hydrolysis, the hexose and pentose sugars of lignocellulosic substrates and supplementary nutrients can be converted into protein-rich yeast biomass by fermentation. Studies have shown that yeasts such as Saccharomyces cerevisiae, Candida utilis and Kluyveromyces marxianus have favourable amino acid composition and excellent properties as protein sources in diets for fish, including carnivorous species such as Atlantic salmon and rainbow trout. Suitable downstream processing of the biomass to disrupt cell walls is required to secure high nutrient digestibility. A number of studies have shown various immunological and health benefits from feeding fish low levels of yeast and yeast-derived cell wall fractions. This review summarises current literature on the potential of yeast from lignocellulosic biomass as an alternative protein source for the aquaculture industry. It is concluded that further research and development within yeast production can be important to secure the future sustainability and economic viability of intensive aquaculture. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Genomics and the making of yeast biodiversity.

Science.gov (United States)

Hittinger, Chris Todd; Rokas, Antonis; Bai, Feng-Yan; Boekhout, Teun; Gonçalves, Paula; Jeffries, Thomas W; Kominek, Jacek; Lachance, Marc-André; Libkind, Diego; Rosa, Carlos A; Sampaio, José Paulo; Kurtzman, Cletus P

2015-12-01

Yeasts are unicellular fungi that do not form fruiting bodies. Although the yeast lifestyle has evolved multiple times, most known species belong to the subphylum Saccharomycotina (syn. Hemiascomycota, hereafter yeasts). This diverse group includes the premier eukaryotic model system, Saccharomyces cerevisiae; the common human commensal and opportunistic pathogen, Candida albicans; and over 1000 other known species (with more continuing to be discovered). Yeasts are found in every biome and continent and are more genetically diverse than angiosperms or chordates. Ease of culture, simple life cycles, and small genomes (∼10-20Mbp) have made yeasts exceptional models for molecular genetics, biotechnology, and evolutionary genomics. Here we discuss recent developments in understanding the genomic underpinnings of the making of yeast biodiversity, comparing and contrasting natural and human-associated evolutionary processes. Only a tiny fraction of yeast biodiversity and metabolic capabilities has been tapped by industry and science. Expanding the taxonomic breadth of deep genomic investigations will further illuminate how genome function evolves to encode their diverse metabolisms and ecologies. Copyright © 2015 Elsevier Ltd. All rights reserved.

Mitigating health risks associated with alcoholic beverages through metabolic engineering.

Science.gov (United States)

Jayakody, Lahiru N; Lane, Stephan; Kim, Heejin; Jin, Yong-Su

2016-02-01

Epidemiological studies have established a positive relationship between the occurrence of cancer and consumption of alcoholic beverages. Metabolic engineering of brewing yeast to reduce potential carcinogenic compounds in alcoholic beverage is technically feasible as well as economically promising. This review presents the mechanisms of formation of potentially carcinogenic components in alcoholic beverages, such as formaldehyde, acetaldehyde, ethyl carbamate, acrylamide, and heavy metals, and introduces effective genetic perturbations to minimize the concentrations of these harmful components. As precise and effective genome editing tools for polyploid yeast are now available, we envision that yeast metabolic engineering might open up new research directions for improving brewing yeast in order to ensure product safety as well as to increase overall quality of alcoholic beverages. Copyright © 2015 Elsevier Ltd. All rights reserved.

New Lager Brewery Strains Obtained by Crossing Techniques Using Cachaça (Brazilian Spirit) Yeasts

Science.gov (United States)

Figueiredo, Bruna Inez Carvalho; Saraiva, Margarete Alice Fontes; de Souza Pimenta, Paloma Patrick; de Souza Testasicca, Miriam Conceição; Sampaio, Geraldo Magela Santos; da Cunha, Aureliano Claret; Afonso, Luis Carlos Crocco; Vieira de Queiroz, Marisa; de Miranda Castro, Ieso

2017-01-01

ABSTRACT The development of hybrids has been an effective approach to generate novel yeast strains with optimal technological profile for use in beer production. This study describes the generation of a new yeast strain for lager beer production by direct mating between two Saccharomyces cerevisiae strains isolated from cachaça distilleries: one that was strongly flocculent, and the other with higher production of acetate esters. The first step in this procedure was to analyze the sporulation ability and reproductive cycle of strains belonging to a specific collection of yeasts isolated from cachaça fermentation vats. Most strains showed high rates of sporulation, spore viability, and homothallic behavior. In order to obtain new yeast strains with desirable properties useful for lager beer production, we compare haploid-to-haploid and diploid-to-diploid mating procedures. Moreover, an assessment of parental phenotype traits showed that the segregant diploid C2-1d generated from a diploid-to-diploid mating experiment showed good fermentation performance at low temperature, high flocculation capacity, and desirable production of acetate esters that was significantly better than that of one type lager strain. Therefore, strain C2-1d might be an important candidate for the production of lager beer, with distinct fruit traces and originating using a non-genetically modified organism (GMO) approach. IMPORTANCE Recent work has suggested the utilization of hybridization techniques for the generation of novel non-genetically modified brewing yeast strains with combined properties not commonly found in a unique yeast strain. We have observed remarkable traits, especially low temperature tolerance, maltotriose utilization, flocculation ability, and production of volatile aroma compounds, among a collection of Saccharomyces cerevisiae strains isolated from cachaça distilleries, which allow their utilization in the production of beer. The significance of our research is in

A review on sustainable yeast biotechnological processes and applications

DEFF Research Database (Denmark)

Nandy, Subir Kumar; Srivastava, R. K.

2018-01-01

Yeast is very well known eukaryotic organism for its remarkable biodiversity and extensive industrial applications. Saccharomyces cerevisiae is one of the most widely used microorganisms in biotechnology with successful applications in the biochemical production. Biological conversion with the fo......Yeast is very well known eukaryotic organism for its remarkable biodiversity and extensive industrial applications. Saccharomyces cerevisiae is one of the most widely used microorganisms in biotechnology with successful applications in the biochemical production. Biological conversion...... with the focus on the different utilization of renewable feedstocks into fuels and chemicals has been intensively investigated due to increasing concerns on sustainability issues worldwide. Compared with its counterparts, Saccharomyces cerevisiae, the baker's yeast, is more industrially relevant due to known...... genetic and physiological background, the availability of a large collection of genetic tools, the compatibility of high-density and large-scale fermentation, and optimize the pathway for variety of products. Therefore, S. cerevisiae is one of the most popular cell factories and has been successfully used...

Genomic mechanisms of stress tolerance for the industrial yeast Saccharomyces cerevisiae against the major chemical classes of inhibitors derived from lignocellulosic biomass conversion

Science.gov (United States)

Scientists at ARS developed tolerant industrial yeast that is able to reduce major chemical classes of inhibitors into less toxic or none toxic compounds while producing ethanol. Using genomic studies, we defined mechanisms of in situ detoxification involved in novel gene functions, vital cofactor r...

Isolation and characterization of awamori yeast mutants with L-leucine accumulation that overproduce isoamyl alcohol.

Science.gov (United States)

Takagi, Hiroshi; Hashida, Keisuke; Watanabe, Daisuke; Nasuno, Ryo; Ohashi, Masataka; Iha, Tomoya; Nezuo, Maiko; Tsukahara, Masatoshi

2015-02-01

Awamori shochu is a traditional distilled alcoholic beverage made from steamed rice in Okinawa, Japan. Although it has a unique aroma that is distinguishable from that of other types of shochu, no studies have been reported on the breeding of awamori yeasts. In yeast, isoamyl alcohol (i-AmOH), known as the key flavor of bread, is mainly produced from α-ketoisocaproate in the pathway of L-leucine biosynthesis, which is regulated by end-product inhibition of α-isopropylmalate synthase (IPMS). Here, we isolated mutants resistant to the L-leucine analog 5,5,5-trifluoro-DL-leucine (TFL) derived from diploid awamori yeast of Saccharomyces cerevisiae. Some of the mutants accumulated a greater amount of intracellular L-leucine, and among them, one mutant overproduced i-AmOH in awamori brewing. This mutant carried an allele of the LEU4 gene encoding the Ser542Phe/Ala551Val variant IPMS, which is less sensitive to feedback inhibition by L-leucine. Interestingly, we found that either of the constituent mutations (LEU4(S542F) and LEU4(A551V)) resulted in the TFL tolerance of yeast cells and desensitization to L-leucine feedback inhibition of IPMS, leading to intracellular L-leucine accumulation. Homology modeling also suggested that L-leucine binding was drastically inhibited in the Ser542Phe, Ala551Val, and Ser542Phe/Ala551Val variants due to steric hindrance in the cavity of IPMS. As we expected, awamori yeast cells expressing LEU4(S542F), LEU4(A551V), and LEU4(S542F/A551V) showed a prominent increase in extracellular i-AmOH production, compared with that of cells carrying the vector only. The approach described here could be a practical method for the breeding of novel awamori yeasts to expand the diversity of awamori taste and flavor. Copyright © 2014 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Yeasts: providing questions and answers for modern biology.

Science.gov (United States)

Dickinson, J R

2000-01-01

Yeasts are to be found in virtually every conceivable niche on this planet and are amazingly varied in their shapes ('morphologies'), life cycles, metabolic capabilities, potentials for use in industrial processes, abilities to spoil food and drink or to act as dangerous human pathogens. This review describes four very different species of yeast to illustrate some of the diversity which exists and, in the case of one of them, Saccharomyces cerevisiae (the familiar baker's or brewer's yeast), the extent of both our knowledge and ignorance.

Peptide (Lys-Leu) and amino acids (Lys and Leu) supplementations improve physiological activity and fermentation performance of brewer's yeast during very high-gravity (VHG) wort fermentation.

Science.gov (United States)

Yang, Huirong; Zong, Xuyan; Cui, Chun; Mu, Lixia; Zhao, Haifeng

2017-12-22

Lys and Leu were generally considered as the key amino acids for brewer's yeast during beer brewing. In the present study, peptide Lys-Leu and a free amino acid (FAA) mixture of Lys and Leu (Lys + Leu) were supplemented in 24 °P wort to examine their effects on physiological activity and fermentation performance of brewer's yeast during very high-gravity (VHG) wort fermentation. Results showed that although both peptide Lys-Leu and their FAA mixture supplementations could increase the growth and viability, intracellular trehalose and glycerol content, wort fermentability, and ethanol content for brewer's yeast during VHG wort fermentation, and peptide was better than their FAA mixture at promoting growth and fermentation for brewer's yeast when the same dose was kept. Moreover, peptide Lys-Leu supplementation significantly increased the assimilation of Asp, but decreased the assimilation of Gly, Ala, Val, (Cys)2, Ile, Leu, Tyr, Phe, Lys, Arg, and Pro. However, the FAA mixture supplementation only promoted the assimilation of Lys and Leu, while reduced the absorption of total amino acids to a greater extent. Thus, the peptide Lys-Leu was more effective than their FAA mixture on the improvement of physiological activity, fermentation performance, and nitrogen metabolism of brewer's yeast during VHG wort fermentation. © 2017 International Union of Biochemistry and Molecular Biology, Inc.

Effect of brewing time and temperature on antioxidant capacity and phenols of white tea: Relationship with sensory properties.

Science.gov (United States)

Pérez-Burillo, S; Giménez, R; Rufián-Henares, J A; Pastoriza, S

2018-05-15

White tea is highly consumed due to its sensory properties and health benefits, although most scientific reports don't include the analysis of both properties. Therefore, the objective of the present study was to unravel the best brewing conditions for optimal extraction of the bioactive compounds and antioxidant capacity, while realising the best sensory properties. Infusions of eighty commercial teas (sold in bags or leaves) were obtained at different time-temperature ratios, studying bioactive compounds (caffeine and individual catechins), antioxidant capacity and sensory analysis. Brewing at 98 °C for 7 min was the best condition to obtain a high content of antioxidant polyphenols and pleasant sensory properties. Those teas sold in bags give rise to tea brews with almost double antioxidant capacity. In conclusion, it is very important to link sensory and chemical data to obtain optimal sensorial quality and the highest healthy properties in white tea infusions. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of storage on the brewing properties of tropical hop substitutes ...

African Journals Online (AJOL)

Tropical hop substitute from utazi (UTZ) Gongronema latifolium, bitter cola (BTC), Garcinia kola, bitter leaf (BTL), Vernonia amygdalina and a blend (1:1.41:2.89) of the three (HSB) respectively, were produced. Stability studies were carried out to predict their suitability for brewing after one to six months storage at 5 ± 1oC ...

Yeast biotechnology: teaching the old dog new tricks.

Science.gov (United States)

Mattanovich, Diethard; Sauer, Michael; Gasser, Brigitte

2014-03-06

Yeasts are regarded as the first microorganisms used by humans to process food and alcoholic beverages. The technology developed out of these ancient processes has been the basis for modern industrial biotechnology. Yeast biotechnology has gained great interest again in the last decades. Joining the potentials of genomics, metabolic engineering, systems and synthetic biology enables the production of numerous valuable products of primary and secondary metabolism, technical enzymes and biopharmaceutical proteins. An overview of emerging and established substrates and products of yeast biotechnology is provided and discussed in the light of the recent literature.

Synthetic genome engineering forging new frontiers for wine yeast.

Science.gov (United States)

Pretorius, Isak S

2017-02-01

Over the past 15 years, the seismic shifts caused by the convergence of biomolecular, chemical, physical, mathematical, and computational sciences alongside cutting-edge developments in information technology and engineering have erupted into a new field of scientific endeavor dubbed Synthetic Biology. Recent rapid advances in high-throughput DNA sequencing and DNA synthesis techniques are enabling the design and construction of new biological parts (genes), devices (gene networks) and modules (biosynthetic pathways), and the redesign of biological systems (cells and organisms) for useful purposes. In 2014, the budding yeast Saccharomyces cerevisiae became the first eukaryotic cell to be equipped with a fully functional synthetic chromosome. This was achieved following the synthesis of the first viral (poliovirus in 2002 and bacteriophage Phi-X174 in 2003) and bacterial (Mycoplasma genitalium in 2008 and Mycoplasma mycoides in 2010) genomes, and less than two decades after revealing the full genome sequence of a laboratory (S288c in 1996) and wine (AWRI1631 in 2008) yeast strain. A large international project - the Synthetic Yeast Genome (Sc2.0) Project - is now underway to synthesize all 16 chromosomes (∼12 Mb carrying ∼6000 genes) of the sequenced S288c laboratory strain by 2018. If successful, S. cerevisiae will become the first eukaryote to cross the horizon of in silico design of complex cells through de novo synthesis, reshuffling, and editing of genomes. In the meantime, yeasts are being used as cell factories for the semi-synthetic production of high-value compounds, such as the potent antimalarial artemisinin, and food ingredients, such as resveratrol, vanillin, stevia, nootkatone, and saffron. As a continuum of previously genetically engineered industrially important yeast strains, precision genome engineering is bound to also impact the study and development of wine yeast strains supercharged with synthetic DNA. The first taste of what the future

Energy use in the food manufacturing industry

Energy Technology Data Exchange (ETDEWEB)

Cleland, A.C.; Earle, M.D.

1980-01-01

A survey was conducted to find the level of energy consumption in the food manufacturing industry, which is the food processing industry excluding meat, dairy, and brewing. Data were used from 74 factories. The manufacturing industry was divided into 14 industry groups and the 4 major energy consumers were found to be fruit and vegetable processing, sugar refining, animal feed production, and bread and pastry baking. The present report summarizes results from the survey. It determined the following: the sources of energy used by the insu industry and the annual consumption of each energy form; the consumption of fuel and electricity in the production of the various manufactured food products; the minimum practical energy requirement for processing the various food products; and the potential for conservation and the methods for achieving savings.

Analysis of elements present in beers and brewing waters by neutron activation analysis

International Nuclear Information System (INIS)

Krausova, Ivana; Kucera, Jan; Dostalek, Pavel; Potesil, Vaclav

2011-01-01

Neutron activation analysis (NAA) was used for determination of Si, Na, K, Ca, Sc, V, Cr, Mn, Fe, Co, Zn, Rb, Cs, and La in Czech beers and brewing waters. The Si concentration in beer determined by the reaction 29 Si(n,p) 29 Al with fast neutrons confirmed that beer is an important Si source in human diet. Determination of other trace elements by NAA with the whole spectrum of reactor neutrons aimed at the feasibility of identification of Gambrinus beers brewed in various breweries. The elements Ca and V appeared to be the best candidates for this purpose. The concentrations of elements determined by NAA were also compared with the recommended daily element intake for humans. The accuracy of the method was proved by analysis of reference materials, specifically NIST SRM 2704 Buffalo River Sediment, NIST SRM 1633b Coal Fly Ash, and NIST SRM 1515 Apple Leaves. (author)

Direct concentration and viability measurement of yeast in corn mash using a novel imaging cytometry method.

Science.gov (United States)

Chan, Leo L; Lyettefi, Emily J; Pirani, Alnoor; Smith, Tim; Qiu, Jean; Lin, Bo

2011-08-01

Worldwide awareness of fossil-fuel depletion and global warming has been increasing over the last 30 years. Numerous countries, including the USA and Brazil, have introduced large-scale industrial fermentation facilities for bioethanol, biobutanol, or biodiesel production. Most of these biofuel facilities perform fermentation using standard baker's yeasts that ferment sugar present in corn mash, sugar cane, or other glucose media. In research and development in the biofuel industry, selection of yeast strains (for higher ethanol tolerance) and fermentation conditions (yeast concentration, temperature, pH, nutrients, etc.) can be studied to optimize fermentation performance. Yeast viability measurement is needed to identify higher ethanol-tolerant yeast strains, which may prolong the fermentation cycle and increase biofuel output. In addition, yeast concentration may be optimized to improve fermentation performance. Therefore, it is important to develop a simple method for concentration and viability measurement of fermenting yeast. In this work, we demonstrate an imaging cytometry method for concentration and viability measurements of yeast in corn mash directly from operating fermenters. It employs an automated cell counter, a dilution buffer, and staining solution from Nexcelom Bioscience to perform enumeration. The proposed method enables specific fluorescence detection of viable and nonviable yeasts, which can generate precise results for concentration and viability of yeast in corn mash. This method can provide an essential tool for research and development in the biofuel industry and may be incorporated into manufacturing to monitor yeast concentration and viability efficiently during the fermentation process.

Effect of storage on the brewing properties of tropical hop substitutes

African Journals Online (AJOL)

SERVER

2007-06-18

Jun 18, 2007 ... Conclusively, tropical hop substitutes stored at 5 ± 1oC to 27 ± 1oC can still be used for brewing even after three to six months storage. .... which is associated with the oxidative depreciation of the soft resins to hard resins ... Changes in the soft resin levels of hop substitutes with storage. Soft resin levels (%).

Effect of yeast storage temperature and flour composition on fermentative activities of baker's yeast

Directory of Open Access Journals (Sweden)

Pejin Dušanka J.

2009-01-01

Full Text Available Baker's yeast is a set of living cells of Saccharomyces cerevisiae. It contains around 70-72% of water, 42-45% of proteins, around 40% of carbohydrates, around 7.5% of lipids (based on dry matter, and vitamin B-complex. On the basis of yeast cell analysis it can be concluded that yeast is a complex biological system which changes in time. The intensity of the changes depends on temperature. Yeast sample was stored at 4°C i 24°C for 12 days. During storage at 4°C, the content of total carbohydrates decreased from 48.81% to 37.50% (dry matter, whereas carbohydrate loss ranged from 40.81% to 29.28% at 24°C. The content of trehalose was 12.33% in the yeast sample stored at 4°C and 0.24% at 24°C. Loss of fermentative activity was 81.76% in the sample stored at 24°C for 12 days. The composition of five samples of 1st category flour was investigated. It was found that flours containing more reducing sugars and maltose enable higher fermentation activities. The flours with higher ash content (in the range 0.5-0.94% had higher contents of phytic acid. Higher ash and phytic contents in flour increased the yeast fermentative efficiency. In bakery industry, a range of ingredients has been applied to improve the product's quality such as surface active substances (emulsifiers, enzymes, sugars and fats. In the paper, the effect of some ingredients added to dough (margarine, saccharose, sodium chloride and malted barley on the yeast fermentative activity was studied. The mentioned ingredients were added to dough at different doses: 0.5, 1.0, 1.5 and 2.0%, flour basis. It was found that the investigated ingredients affected the fermentative activity of yeast and improved the bread quality.

Pivovarské kvasinky a reakce na stres

Czech Academy of Sciences Publication Activity Database

Sigler, Karel; Matoulková, D.

2011-01-01

Roč. 57, 7-8 (2011), s. 277-284 ISSN 0023-5830 R&D Projects: GA MŠk 1M0570 Institutional research plan: CEZ:AV0Z50200510 Keywords : laboratory yeast * brewing yeast * stresses Subject RIV: EE - Microbiology, Virology

Estimating alcohol content of traditional brew in Western Kenya using culturally relevant methods: the case for cost over volume.

Science.gov (United States)

Papas, Rebecca K; Sidle, John E; Wamalwa, Emmanuel S; Okumu, Thomas O; Bryant, Kendall L; Goulet, Joseph L; Maisto, Stephen A; Braithwaite, R Scott; Justice, Amy C

2010-08-01

Traditional homemade brew is believed to represent the highest proportion of alcohol use in sub-Saharan Africa. In Eldoret, Kenya, two types of brew are common: chang'aa, spirits, and busaa, maize beer. Local residents refer to the amount of brew consumed by the amount of money spent, suggesting a culturally relevant estimation method. The purposes of this study were to analyze ethanol content of chang'aa and busaa; and to compare two methods of alcohol estimation: use by cost, and use by volume, the latter the current international standard. Laboratory results showed mean ethanol content was 34% (SD = 14%) for chang'aa and 4% (SD = 1%) for busaa. Standard drink unit equivalents for chang'aa and busaa, respectively, were 2 and 1.3 (US) and 3.5 and 2.3 (Great Britain). Using a computational approach, both methods demonstrated comparable results. We conclude that cost estimation of alcohol content is more culturally relevant and does not differ in accuracy from the international standard.

Effect of the type of brewing water on the chemical composition, sensory quality and antioxidant capacity of Chinese teas.

Science.gov (United States)

Xu, Yong-Quan; Zou, Chun; Gao, Ying; Chen, Jian-Xin; Wang, Fang; Chen, Gen-Sheng; Yin, Jun-Feng

2017-12-01

The physicochemical characteristics, sensory quality, and antioxidant activity of tea infusions prepared with purified water (PW), mineral water (MW), mountain spring water (MSW), and tap water (TW) from Hangzhou were investigated. The results showed that the taste quality, catechin concentration, and antioxidant capacity of green, oolong, and black tea infusions prepared using MW and TW were significantly lower than those prepared using PW. Extraction of catechins and caffeine was reduced with high-conductivity water, while high pH influenced the stability of catechins. PW and MSW were more suitable for brewing green and oolong teas, while MSW, with low pH and moderate ion concentration, was the most suitable water for brewing black tea. Lowering the pH of mineral water partially improved the taste quality and increased the concentration of catechins in the infusions. These results aid selection of the most appropriate water for brewing Chinese teas. Copyright © 2016 Elsevier Ltd. All rights reserved.

Biotechnological production of carotenoids by yeasts: an overview

Science.gov (United States)

2014-01-01

Nowadays, carotenoids are valuable molecules in different industries such as chemical, pharmaceutical, poultry, food and cosmetics. These pigments not only can act as vitamin A precursors, but also they have coloring and antioxidant properties, which have attracted the attention of the industries and researchers. The carotenoid production through chemical synthesis or extraction from plants is limited by low yields that results in high production costs. This leads to research of microbial production of carotenoids, as an alternative that has shown better yields than other aforementioned. In addition, the microbial production of carotenoids could be a better option about costs, looking for alternatives like the use of low-cost substrates as agro-industrials wastes. Yeasts have demonstrated to be carotenoid producer showing an important growing capacity in several agro-industrial wastes producing high levels of carotenoids. Agro-industrial wastes provide carbon and nitrogen source necessary, and others elements to carry out the microbial metabolism diminishing the production costs and avoiding pollution from these agro-industrial wastes to the environmental. Herein, we discuss the general and applied concepts regarding yeasts carotenoid production and the factors influencing carotenogenesis using agro-industrial wastes as low-cost substrates. PMID:24443802

Kombucha brewing under the Food and Drug Administration model Food Code: risk analysis and processing guidance.

Science.gov (United States)

Nummer, Brian A

2013-11-01

Kombucha is a fermented beverage made from brewed tea and sugar. The taste is slightly sweet and acidic and it may have residual carbon dioxide. Kombucha is consumed in many countries as a health beverage and it is gaining in popularity in the U.S. Consequently, many retailers and food service operators are seeking to brew this beverage on site. As a fermented beverage, kombucha would be categorized in the Food and Drug Administration model Food Code as a specialized process and would require a variance with submission of a food safety plan. This special report was created to assist both operators and regulators in preparing or reviewing a kombucha food safety plan.

Yeast biotechnology: teaching the old dog new tricks

Science.gov (United States)

2014-01-01

Yeasts are regarded as the first microorganisms used by humans to process food and alcoholic beverages. The technology developed out of these ancient processes has been the basis for modern industrial biotechnology. Yeast biotechnology has gained great interest again in the last decades. Joining the potentials of genomics, metabolic engineering, systems and synthetic biology enables the production of numerous valuable products of primary and secondary metabolism, technical enzymes and biopharmaceutical proteins. An overview of emerging and established substrates and products of yeast biotechnology is provided and discussed in the light of the recent literature. PMID:24602262

Structure, cell wall elasticity and polysaccharide properties of living yeast cells, as probed by AFM

International Nuclear Information System (INIS)

Alsteens, David; Dupres, Vincent; Evoy, Kevin Mc; Dufrene, Yves F; Wildling, Linda; Gruber, Hermann J

2008-01-01

Although the chemical composition of yeast cell walls is known, the organization, assembly, and interactions of the various macromolecules remain poorly understood. Here, we used in situ atomic force microscopy (AFM) in three different modes to probe the ultrastructure, cell wall elasticity and polymer properties of two brewing yeast strains, i.e. Saccharomyces carlsbergensis and S. cerevisiae. Topographic images of the two strains revealed smooth and homogeneous cell surfaces, and the presence of circular bud scars on dividing cells. Nanomechanical measurements demonstrated that the cell wall elasticity of S. carlsbergensis is homogeneous. By contrast, the bud scar of S. cerevisiae was found to be stiffer than the cell wall, presumably due to the accumulation of chitin. Notably, single molecule force spectroscopy with lectin-modified tips revealed major differences in polysaccharide properties of the two strains. Polysaccharides were clearly more extended on S. cerevisiae, suggesting that not only oligosaccharides, but also polypeptide chains of the mannoproteins were stretched. Consistent with earlier cell surface analyses, these findings may explain the very different aggregation properties of the two organisms. This study demonstrates the power of using multiple complementary AFM modalities for probing the organization and interactions of the various macromolecules of microbial cell walls

2018-03-25T18:09:40Z https://www.ajol.info/index.php/all/oai oai:ojs ...

African Journals Online (AJOL)

Alcohol production; fermentation; induced mutants; Saccharomyces cerevisiae; viability Brewing yeast, Saccharomyces. Cerevisiae cultured on malt extract agar was UV-irradiated. Eighteen mutant yeasts (SCM 01 – SCM 18) selected (after visual examination) were tested for fermentation, alcohol production and viability by ...

A Novel GH7 Endo-β-1,4-Glucanase from Neosartorya fischeri P1 with Good Thermostability, Broad Substrate Specificity and Potential Application in the Brewing Industry.

Directory of Open Access Journals (Sweden)

Yun Liu

Full Text Available An endo-β-1,4-glucanase gene, cel7A, was cloned from the thermophilic cellulase-producing fungus Neosartorya fischeri P1 and expressed in Pichia pastoris. The 1,410-bp full-length gene encodes a polypeptide of 469 amino acids consisting of a putative signal peptide at residues 1-20, a catalytic domain of glycoside hydrolase family 7 (GH7, a short Thr/Ser-rich linker and a family 1 carbohydrate-binding module (CBM 1. The purified recombinant Cel7A had pH and temperature optima of pH 5.0 and 60°C, respectively, and showed broad pH adaptability (pH 3.0-6.0 and excellent stability at pH3.0-8.0 and 60°C. Belonging to the group of nonspecific endoglucanases, Cel7A exhibited the highest activity on barley β-glucan (2020 ± 9 U mg-1, moderate on lichenan and CMC-Na, and weak on laminarin, locust bean galactomannan, Avicel, and filter paper. Under simulated mashing conditions, addition of Cel7A (99 μg reduced the mash viscosity by 9.1% and filtration time by 24.6%. These favorable enzymatic properties make Cel7A as a good candidate for applications in the brewing industry.

Yeast glycolipid biosurfactants.

Science.gov (United States)

Jezierska, Sylwia; Claus, Silke; Van Bogaert, Inge

2017-10-25

Various yeasts, both conventional and exotic ones, are known to produce compounds useful to mankind. Ethanol is the most known of these compounds, but more complex molecules such as amphiphilic biosurfactants can also be derived from eukaryotic microorganisms at an industrially and commercially relevant scale. Among them, glycolipids are the most promising, due to their attractive properties and high product titers. Many of these compounds can be considered as secondary metabolites with a specific function for the host. Hence, a dedicated biosynthetic process enables regulation and combines pathways delivering the lipidic moiety and the hydrophilic carbohydrate part of the glycolipid. In this Review, we will discuss the biosynthetic and regulatory aspects of the yeast-derived sophorolipids, mannosylerythritol lipids, and cellobiose lipids, with special emphasis on the relation between glycolipid synthesis and the general lipid metabolism. © 2017 Federation of European Biochemical Societies.

The occurrence of spoilage yeasts in cream-filled bakery products.

Science.gov (United States)

Osimani, Andrea; Milanović, Vesna; Taccari, Manuela; Cardinali, Federica; Pasquini, Marina; Aquilanti, Lucia; Clementi, Francesca

2017-04-01

Filling creams can provide an adequate substrate for spoilage yeasts because some yeasts can tolerate the high osmotic stress in these products. To discover the source of spoilage of a cream-filled baked product, end products, raw materials, indoor air and work surfaces were subjected to microbiological and molecular analyses. The efficacy of disinfectants against spoilage yeasts was also assessed. The analyses on end products revealed the presence of the closest relatives to Zygosaccharomyces bailii with counts ranging from 1.40 to 4.72 log cfu g -1 . No spoilage yeasts were found in the indoor air and work surfaces. Polymerase chain reaction-denaturing gradient gel electrophoresis analysis, carried out directly on filling creams collected from unopened cans, showed the presence of bands ascribed to the closest relatives to Z. bailii sensu lato, although with counts products, reliable and sensitive methods must be used. Moreover, hygiene and the application of good manufacturing practices represent the most efficient way for the prevention and minimization of cross-contamination. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Yeast strains designed for 2. generation bioethanol production. Final report

Energy Technology Data Exchange (ETDEWEB)

Roennow, B.

2013-04-15

The aim of the project was to develop a suitable fermentation organism for 2G bioethanol production that would efficiently ferment all of the sugars in lignocellulosic biomass into ethanol at a commercially viable rate (comparable to yeast based 1G ethanol production). More specifically, a yeast strain would be developed with the ability to ferment also the pentoses in lignocellulosic biomass and thereby increase the ethanol yield of the process by 30-45% with a profound positive effect on the total process economy. The project has succeeded in developing a new industrial yeast strain V1. The yeast strain can transform the difficult C5 sugars to ethanol from waste products such as straw and the like from the agricultural sector. The classic issues relating to industrial uses such as inhibitor and ethanol tolerance and high ethanol production is resolved satisfactorily. The potential of the use of the new strain for 2nd generation bioethanol production is that the ethanol yields increase by 30-45%. With the increased ethanol yield follows a marked improvement in the overall process economics. (LN)

Non-conventional yeast species for lowering ethanol content of wines

Directory of Open Access Journals (Sweden)

Maurizio eCiani

2016-05-01

Full Text Available Rising sugar content in grape must, and the concomitant increase in alcohol levels in wine, are some of the main challenges affecting the winemaking industry nowadays. Among the several alternative solutions currently under study, the use of non-conventional yeasts during fermentation holds good promise for contributing to relieve this problem. Non-Saccharomyces wine yeast species comprise a high number or species, so encompassing a wider physiological diversity than Saccharomyces cerevisiae. Indeed, the current oenological interest of these microorganisms was initially triggered by their potential positive contribution to the sensorial complexity of quality wines, through the production of aroma and other sensory-active compounds. This diversity also involves ethanol yield on sugar, one of the most invariant metabolic traits of S. cerevisiae. This review gathers recent research on non-Saccharomyces yeasts, aiming to produce wines with lower alcohol content than those from pure Saccharomyces starters. Critical aspects discussed include the selection of suitable yeast strains (considering there is a noticeable intra-species diversity for ethanol yield, as shown for other fermentation traits, identification of key environmental parameters influencing ethanol yields (including the use of controlled oxygenation conditions, and managing mixed fermentations, by either the sequential or simultaneous inoculation of S. cerevisiae and non-Saccharomyces starter cultures. The feasibility, at the industrial level, of using non-Saccharomyces yeasts for reducing alcohol levels in wine will require an improved understanding of the metabolism of these alternative yeast species, as well as of the interactions between different yeast starters during the fermentation of grape must.

Non-conventional Yeast Species for Lowering Ethanol Content of Wines

Science.gov (United States)

Ciani, Maurizio; Morales, Pilar; Comitini, Francesca; Tronchoni, Jordi; Canonico, Laura; Curiel, José A.; Oro, Lucia; Rodrigues, Alda J.; Gonzalez, Ramon

2016-01-01

Rising sugar content in grape must, and the concomitant increase in alcohol levels in wine, are some of the main challenges affecting the winemaking industry nowadays. Among the several alternative solutions currently under study, the use of non-conventional yeasts during fermentation holds good promise for contributing to relieve this problem. Non-Saccharomyces wine yeast species comprise a high number or species, so encompassing a wider physiological diversity than Saccharomyces cerevisiae. Indeed, the current oenological interest of these microorganisms was initially triggered by their potential positive contribution to the sensorial complexity of quality wines, through the production of aroma and other sensory-active compounds. This diversity also involves ethanol yield on sugar, one of the most invariant metabolic traits of S. cerevisiae. This review gathers recent research on non-Saccharomyces yeasts, aiming to produce wines with lower alcohol content than those from pure Saccharomyces starters. Critical aspects discussed include the selection of suitable yeast strains (considering there is a noticeable intra-species diversity for ethanol yield, as shown for other fermentation traits), identification of key environmental parameters influencing ethanol yields (including the use of controlled oxygenation conditions), and managing mixed fermentations, by either the sequential or simultaneous inoculation of S. cerevisiae and non-Saccharomyces starter cultures. The feasibility, at the industrial level, of using non-Saccharomyces yeasts for reducing alcohol levels in wine will require an improved understanding of the metabolism of these alternative yeast species, as well as of the interactions between different yeast starters during the fermentation of grape must. PMID:27199967

Degradation Dynamics and Dietary Risk Assessments of Two Neonicotinoid Insecticides during Lonicera japonica Planting, Drying, and Tea Brewing Processes.

Science.gov (United States)

Fang, Qingkui; Shi, Yanhong; Cao, Haiqun; Tong, Zhou; Xiao, Jinjing; Liao, Min; Wu, Xiangwei; Hua, Rimao

2017-03-01

The degradation dynamics and dietary risk assessments of thiamethoxam and thiacloprid during Lonicera japonica planting, drying, and tea brewing processes were systematically investigated using high-performance liquid chromatography. The half-lives of thiamethoxam and thiacloprid were 1.0-4.1 d in the honeysuckle flowers and leaves, with degradation rate constants k ranging from -0.169 to -0.696. The safety interval time was 7 d. The sun- and oven-drying (70 °C) percent digestions were 59.4-81.0% for the residues, which were higher than the shade- and oven-drying percentages at lower temperatures (30, 40, 50, and 60 °C, which ranged from 37.7% to 57.0%). The percent transfers of thiamethoxam and thiacloprid were 0-48.4% and 0-25.2%, respectively, for the different tea brewing conditions. On the basis of the results of this study, abiding by the safety interval time is important, and using reasonable drying methods and tea brewing conditions can reduce the transfer of thiamethoxam and thiacloprid to humans.

Phenotypic and metabolic traits of commercial Saccharomyces cerevisiae yeasts.

Science.gov (United States)

Barbosa, Catarina; Lage, Patrícia; Vilela, Alice; Mendes-Faia, Arlete; Mendes-Ferreira, Ana

2014-01-01

Currently, pursuing yeast strains that display both a high potential fitness for alcoholic fermentation and a favorable impact on quality is a major goal in the alcoholic beverage industry. This considerable industrial interest has led to many studies characterizing the phenotypic and metabolic traits of commercial yeast populations. In this study, 20 Saccharomyces cerevisiae strains from different geographical origins exhibited high phenotypic diversity when their response to nine biotechnologically relevant conditions was examined. Next, the fermentation fitness and metabolic traits of eight selected strains with a unique phenotypic profile were evaluated in a high-sugar synthetic medium under two nitrogen regimes. Although the strains exhibited significant differences in nitrogen requirements and utilization rates, a direct relationship between nitrogen consumption, specific growth rate, cell biomass, cell viability, acetic acid and glycerol formation was only observed under high-nitrogen conditions. In contrast, the strains produced more succinic acid under the low-nitrogen regime, and a direct relationship with the final cell biomass was established. Glucose and fructose utilization patterns depended on both yeast strain and nitrogen availability. For low-nitrogen fermentation, three strains did not fully degrade the fructose. This study validates phenotypic and metabolic diversity among commercial wine yeasts and contributes new findings on the relationship between nitrogen availability, yeast cell growth and sugar utilization. We suggest that measuring nitrogen during the stationary growth phase is important because yeast cells fermentative activity is not exclusively related to population size, as previously assumed, but it is also related to the quantity of nitrogen consumed during this growth phase.

Introducing a new breed of wine yeast: interspecific hybridisation between a commercial Saccharomyces cerevisiae wine yeast and Saccharomyces mikatae.

Science.gov (United States)

Bellon, Jennifer R; Schmid, Frank; Capone, Dimitra L; Dunn, Barbara L; Chambers, Paul J

2013-01-01

Interspecific hybrids are commonplace in agriculture and horticulture; bread wheat and grapefruit are but two examples. The benefits derived from interspecific hybridisation include the potential of generating advantageous transgressive phenotypes. This paper describes the generation of a new breed of wine yeast by interspecific hybridisation between a commercial Saccharomyces cerevisiae wine yeast strain and Saccharomyces mikatae, a species hitherto not associated with industrial fermentation environs. While commercially available wine yeast strains provide consistent and reliable fermentations, wines produced using single inocula are thought to lack the sensory complexity and rounded palate structure obtained from spontaneous fermentations. In contrast, interspecific yeast hybrids have the potential to deliver increased complexity to wine sensory properties and alternative wine styles through the formation of novel, and wider ranging, yeast volatile fermentation metabolite profiles, whilst maintaining the robustness of the wine yeast parent. Screening of newly generated hybrids from a cross between a S. cerevisiae wine yeast and S. mikatae (closely-related but ecologically distant members of the Saccharomyces sensu stricto clade), has identified progeny with robust fermentation properties and winemaking potential. Chemical analysis showed that, relative to the S. cerevisiae wine yeast parent, hybrids produced wines with different concentrations of volatile metabolites that are known to contribute to wine flavour and aroma, including flavour compounds associated with non-Saccharomyces species. The new S. cerevisiae x S. mikatae hybrids have the potential to produce complex wines akin to products of spontaneous fermentation while giving winemakers the safeguard of an inoculated ferment.

Determination of Pyrethroids in Tea Brew by GC-MS Combined with SPME with Multiwalled Carbon Nanotube Coated Fiber.

Science.gov (United States)

Ren, Dongxia; Sun, Chengjun; Ma, Guanqun; Yang, Danni; Zhou, Chen; Xie, Jiayu; Li, Yongxin

2018-01-01

A new method has been developed to simultaneously determine 7 pyrethroid residues in tea brew using gas chromatography-mass spectrometry (GC-MS) combined with solid phase microextraction (SPME) with multiwalled carbon nanotubes (MWCNTs) coated fiber. The MWCNTs coated fiber of SPME was homemade by using stainless steel wire as coating carrier and polyacrylonitrile (PAN) solution as adhesive glue. Under the optimized conditions, a good linearity was shown for bifenthrin, fenpropathrin, permethrin, and cyfluthrin in 1-50 ng mL -1 and for cypermethrin, fenvalerate, and deltamethrin in 5-50 ng mL -1 . The correlation coefficients were in the range of 0.9948-0.9999. The average recoveries of 7 pyrethroids were 94.2%-107.3% and the relative standard deviations (RSDs) were less than 15%. The detection limit of the method ranged from 0.12 to 1.65 ng mL -1 . The tea brew samples made from some commercial tea samples were analyzed. Among them, bifenthrin, fenpropathrin, and permethrin were found. The results show that the method is rapid and sensitive and requires low organic reagent consumption, which can be well used for the detection of the pyrethroids in tea brew.

Genomic structural variation contributes to phenotypic change of industrial bioethanol yeast Saccharomyces cerevisiae.

Science.gov (United States)

Zhang, Ke; Zhang, Li-Jie; Fang, Ya-Hong; Jin, Xin-Na; Qi, Lei; Wu, Xue-Chang; Zheng, Dao-Qiong

2016-03-01

Genomic structural variation (GSV) is a ubiquitous phenomenon observed in the genomes of Saccharomyces cerevisiae strains with different genetic backgrounds; however, the physiological and phenotypic effects of GSV are not well understood. Here, we first revealed the genetic characteristics of a widely used industrial S. cerevisiae strain, ZTW1, by whole genome sequencing. ZTW1 was identified as an aneuploidy strain and a large-scale GSV was observed in the ZTW1 genome compared with the genome of a diploid strain YJS329. These GSV events led to copy number variations (CNVs) in many chromosomal segments as well as one whole chromosome in the ZTW1 genome. Changes in the DNA dosage of certain functional genes directly affected their expression levels and the resultant ZTW1 phenotypes. Moreover, CNVs of large chromosomal regions triggered an aneuploidy stress in ZTW1. This stress decreased the proliferation ability and tolerance of ZTW1 to various stresses, while aneuploidy response stress may also provide some benefits to the fermentation performance of the yeast, including increased fermentation rates and decreased byproduct generation. This work reveals genomic characters of the bioethanol S. cerevisiae strain ZTW1 and suggests that GSV is an important kind of mutation that changes the traits of industrial S. cerevisiae strains. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Use of the industrial yeast Candida utilis for cadmium sorption

Czech Academy of Sciences Publication Activity Database

Kujan, Petr; Prell, Aleš; Šafář, Hynek; Sobotka, Miroslav; Řezanka, Tomáš; Holler, Pavel

2006-01-01

Roč. 51, č. 4 (2006), s. 257-260 ISSN 0015-5632 Institutional research plan: CEZ:AV0Z50200510 Keywords : candida utilis * cadmium * yeast Subject RIV: EE - Microbiology, Virology Impact factor: 0.963, year: 2006

Changes in volatile profile of soybean residue (okara) upon solid-state fermentation by yeasts.

Science.gov (United States)

Vong, Weng Chan; Liu, Shao-Quan

2017-01-01

Soybean residue (okara), a by-product of soymilk, is produced in large volumes by the soy food industry and is often discarded due to its undesirable flavour. As it contains a considerable amount of protein and fats, biotransformation of okara to improve its flavour presents an opportunity for alternative utilisation. This paper evaluated 10 yeasts in the solid-state fermentation of okara based on their volatile profiles as analysed with HS-SPME GC-MS/FID. Four 'dairy yeasts' (Geotrichum candidum, Yarrowia lipolytica, Debaryomyces hansenii and Kluyveromyces lactis) and six 'wine yeasts' (Saccharomyces cerevisiae, Lachancea thermotolerans, Metschnikowia pulcherrima, Pichia kluyveri, Torulaspora delbrueckii, and Williopsis saturnus) were studied. The main off-odourants in okara, hexanal and trans-2-hexenal, significantly decreased after fermentation due to their bioconversion into methyl ketones and/or esters. The okara fermented by dairy yeasts contained greater proportions of methyl ketones, while that by wine yeasts contained more ethyl and acetyl esters. Notably, the okara fermented by W. saturnus contained 13 esters and the total GC-FID peak area of esters was about 380 times that in fresh okara, leading to a perceptible fruity note. Okara can be exploited as an inexpensive substrate for bioflavour extraction and/or a more pleasant food ingredient via yeast fermentation. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Dissipation of Flonicamid in Honeysuckle and Its Transfer during Brewing Process.

Science.gov (United States)

Wang, Yujie; Xue, Jian; Jin, Hongyu; Ma, Shuangcheng

2017-05-01

The dissipation of flonicamid in Honeysuckle and transfer pattern from Honeysuckle to its tea infusion were investigated. Flonicamid was applied on Honeysuckle crop at two dosages, 60 g of active gradient per hectare (g a.i. hm -2 ) and 180 g a.i. hm -2 (recommended and triple the recommended) in Fenqiu, Henan Province in 2015 and 2016. Gas Chromatography-Electron Capture Detector (GC-ECD) detection methods were developed for the analysis of flonicamid residues in honeysuckles and its infusion. The recoveries in both honeysuckles and its infusion ranged from 81.5 to 101.7% with relative standard deviations (RSDs) of 3.2-9.1%. The dissipations of flonicamid in Honeysuckle were found to follow the first order kinetics with half-life ranging between 2.8 and 3.2 d. After recommended dose pesticide application, contents of flonicamid residues were lower than theoretical maximum residue limit (tMRL). Flonicamid residues can easily transfer from Honeysuckle to its tea infusion and transfer rates of flonicamid decrease with the brewing temperature reduction or the brewing times increase. These results are helpful to establish maximum residue limit and develop guidance on the appropriate and secure use of flonicamid in Honeysuckle.

MALDI-TOF MS as a tool to identify foodborne yeasts and yeast-like fungi.

Science.gov (United States)

Quintilla, Raquel; Kolecka, Anna; Casaregola, Serge; Daniel, Heide M; Houbraken, Jos; Kostrzewa, Markus; Boekhout, Teun; Groenewald, Marizeth

2018-02-02

Since food spoilage by yeasts causes high economic losses, fast and accurate identifications of yeasts associated with food and food-related products are important for the food industry. In this study the efficiency of the matrix assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) to identify food related yeasts was evaluated. A CBS in-house MALDI-TOF MS database was created and later challenged with a blinded test set of 146 yeast strains obtained from food and food related products. Ninety eight percent of the strains were correctly identified with log score values>1.7. One strain, Mrakia frigida, gained a correct identification with a score value1.7. Ambiguous identifications were observed due to two incorrect reference mass spectra's found in the commercial database BDAL v.4.0, namely Candida sake DSM 70763 which was re-identified as Candida oleophila, and Candida inconspicua DSM 70631 which was re-identified as Pichia membranifaciens. MALDI-TOF MS can distinguish between most of the species, but for some species complexes, such as the Kazachstania telluris and Mrakia frigida complexes, MALDI-TOF MS showed limited resolution and identification of sibling species was sometimes problematic. Despite this, we showed that the MALDI-TOF MS is applicable for routine identification and validation of foodborne yeasts, but a further update of the commercial reference databases is needed. Copyright © 2017 Elsevier B.V. All rights reserved.

The yeast stands alone: the future of protein biologic production.

Science.gov (United States)

Love, Kerry R; Dalvie, Neil C; Love, J Christopher

2017-12-22

Yeasts are promising alternative hosts for the manufacturing of recombinant protein therapeutics because they simply and efficiently meet needs for both platform and small-market drugs. Fast accumulation of biomass and low-cost media reduce the cost-of-goods when using yeast, which in turn can enable agile, small-volume manufacturing facilities. Small, tractable yeast genomes are amenable to rapid process development, facilitating strain and product quality by design. Specifically, Pichia pastoris is becoming a widely accepted yeast for biopharmaceutical manufacturing in much of the world owing to a clean secreted product and the rapidly expanding understanding of its cell biology as a host organism. We advocate for a near term partnership spanning industry and academia to promote open source, timely development of yeast hosts. Copyright © 2017. Published by Elsevier Ltd.

Assessment of waste management in a brewing industry in Nigeria ...

African Journals Online (AJOL)

International Journal of Natural and Applied Sciences ... in the generation of offensive by – products in terms of industrial wastes in our environment. ... The obtained values were compared with the Federal Environmental Protection Agency ...

Engineering of the glycerol decomposition pathway and cofactor regulation in an industrial yeast improves ethanol production.

Science.gov (United States)

Zhang, Liang; Tang, Yan; Guo, Zhongpeng; Shi, Guiyang

2013-10-01

Glycerol is a major by-product of industrial ethanol production and its formation consumes up to 4 % of the sugar substrate. This study modified the glycerol decomposition pathway of an industrial strain of Saccharomyces cerevisiae to optimize the consumption of substrate and yield of ethanol. This study is the first to couple glycerol degradation with ethanol formation, to the best of our knowledge. The recombinant strain overexpressing GCY1 and DAK1, encoding glycerol dehydrogenase and dihydroxyacetone kinase, respectively, in glycerol degradation pathway, exhibited a moderate increase in ethanol yield (2.9 %) and decrease in glycerol yield (24.9 %) compared to the wild type with the initial glucose concentration of 15 % under anaerobic conditions. However, when the mhpF gene, encoding acetylating NAD⁺-dependent acetaldehyde dehydrogenase from Escherichia coli, was co-expressed in the aforementioned recombinant strain, a further increase in ethanol yield by 5.5 % and decrease in glycerol yield by 48 % were observed for the resultant recombinant strain GDMS1 when acetic acid was added into the medium prior to inoculation compared to the wild type. The process outlined in this study which enhances glycerol consumption and cofactor regulation in an industrial yeast is a promising metabolic engineering strategy to increase ethanol production by reducing the formation of glycerol.

Guidelines and recommendations on yeast cell death nomenclature

Directory of Open Access Journals (Sweden)

Didac Carmona-Gutierrez

2018-01-01

Full Text Available Elucidating the biology of yeast in its full complexity has major implications for science, medicine and industry. One of the most critical processes determining yeast life and physiology is cellular demise. However, the investigation of yeast cell death is a relatively young field, and a widely accepted set of concepts and terms is still missing. Here, we propose unified criteria for the definition of accidental, regulated, and programmed forms of cell death in yeast based on a series of morphological and biochemical criteria. Specifically, we provide consensus guidelines on the differential definition of terms including apoptosis, regulated necrosis, and autophagic cell death, as we refer to additional cell death routines that are relevant for the biology of (at least some species of yeast. As this area of investigation advances rapidly, changes and extensions to this set of recommendations will be implemented in the years to come. Nonetheless, we strongly encourage the authors, reviewers and editors of scientific articles to adopt these collective standards in order to establish an accurate framework for yeast cell death research and, ultimately, to accelerate the progress of this vibrant field of research.

Guidelines and recommendations on yeast cell death nomenclature

Science.gov (United States)

Carmona-Gutierrez, Didac; Bauer, Maria Anna; Zimmermann, Andreas; Aguilera, Andrés; Austriaco, Nicanor; Ayscough, Kathryn; Balzan, Rena; Bar-Nun, Shoshana; Barrientos, Antonio; Belenky, Peter; Blondel, Marc; Braun, Ralf J.; Breitenbach, Michael; Burhans, William C.; Büttner, Sabrina; Cavalieri, Duccio; Chang, Michael; Cooper, Katrina F.; Côrte-Real, Manuela; Costa, Vítor; Cullin, Christophe; Dawes, Ian; Dengjel, Jörn; Dickman, Martin B.; Eisenberg, Tobias; Fahrenkrog, Birthe; Fasel, Nicolas; Fröhlich, Kai-Uwe; Gargouri, Ali; Giannattasio, Sergio; Goffrini, Paola; Gourlay, Campbell W.; Grant, Chris M.; Greenwood, Michael T.; Guaragnella, Nicoletta; Heger, Thomas; Heinisch, Jürgen; Herker, Eva; Herrmann, Johannes M.; Hofer, Sebastian; Jiménez-Ruiz, Antonio; Jungwirth, Helmut; Kainz, Katharina; Kontoyiannis, Dimitrios P.; Ludovico, Paula; Manon, Stéphen; Martegani, Enzo; Mazzoni, Cristina; Megeney, Lynn A.; Meisinger, Chris; Nielsen, Jens; Nyström, Thomas; Osiewacz, Heinz D.; Outeiro, Tiago F.; Park, Hay-Oak; Pendl, Tobias; Petranovic, Dina; Picot, Stephane; Polčic, Peter; Powers, Ted; Ramsdale, Mark; Rinnerthaler, Mark; Rockenfeller, Patrick; Ruckenstuhl, Christoph; Schaffrath, Raffael; Segovia, Maria; Severin, Fedor F.; Sharon, Amir; Sigrist, Stephan J.; Sommer-Ruck, Cornelia; Sousa, Maria João; Thevelein, Johan M.; Thevissen, Karin; Titorenko, Vladimir; Toledano, Michel B.; Tuite, Mick; Vögtle, F.-Nora; Westermann, Benedikt; Winderickx, Joris; Wissing, Silke; Wölfl, Stefan; Zhang, Zhaojie J.; Zhao, Richard Y.; Zhou, Bing; Galluzzi, Lorenzo; Kroemer, Guido; Madeo, Frank

2018-01-01

Elucidating the biology of yeast in its full complexity has major implications for science, medicine and industry. One of the most critical processes determining yeast life and physiology is cellular demise. However, the investigation of yeast cell death is a relatively young field, and a widely accepted set of concepts and terms is still missing. Here, we propose unified criteria for the definition of accidental, regulated, and programmed forms of cell death in yeast based on a series of morphological and biochemical criteria. Specifically, we provide consensus guidelines on the differential definition of terms including apoptosis, regulated necrosis, and autophagic cell death, as we refer to additional cell death routines that are relevant for the biology of (at least some species of) yeast. As this area of investigation advances rapidly, changes and extensions to this set of recommendations will be implemented in the years to come. Nonetheless, we strongly encourage the authors, reviewers and editors of scientific articles to adopt these collective standards in order to establish an accurate framework for yeast cell death research and, ultimately, to accelerate the progress of this vibrant field of research. PMID:29354647

METHOD FOR THE PRODUCTION OF HETEROLOGOUS POLYPEPTIDES IN TRANSFORMED YEAST CELLS

DEFF Research Database (Denmark)

2000-01-01

The invention describes industrial fermentation of a $i(Saccharomyces) yeast species for production of a heterologous product encoded by a plasmid or DNA contained in said $i(Saccharomyces) yeast species with method utilizes the substrate more efficiently and without fermentative metabolism...... resulting in formation of ethanol and other unwanted primary products of fermentative activity whereby high yields of the heterologous product are obtained. The $i(Saccharomyces) yeast species is preferably a Crabtree negative $i(Saccharomyces species) in particular $i(Saccharomyces kluyveri)....

Effects of feedstock and co-culture of Lactobacillus fermentum and wild Saccharomyces cerevisiae strain during fuel ethanol fermentation by the industrial yeast strain PE-2.

Science.gov (United States)

Reis, Vanda R; Bassi, Ana Paula G; Cerri, Bianca C; Almeida, Amanda R; Carvalho, Isis G B; Bastos, Reinaldo G; Ceccato-Antonini, Sandra R

2018-02-16

Even though contamination by bacteria and wild yeasts are frequently observed during fuel ethanol fermentation, our knowledge regarding the effects of both contaminants together is very limited, especially considering that the must composition can vary from exclusively sugarcane juice to a mixture of molasses and juice, affecting the microbial development. Here we studied the effects of the feedstock (sugarcane juice and molasses) and the co-culture of Lactobacillus fermentum and a wild Saccharomyces cerevisiae strain (rough colony and pseudohyphae) in single and multiple-batch fermentation trials with an industrial strain of S. cerevisiae (PE-2) as starter yeast. The results indicate that in multiple-cycle batch system, the feedstock had a minor impact on the fermentation than in single-cycle batch system, however the rough yeast contamination was more harmful than the bacterial contamination in multiple-cycle batch fermentation. The inoculation of both contaminants did not potentiate the detrimental effect in any substrate. The residual sugar concentration in the fermented broth had a higher concentration of fructose than glucose for all fermentations, but in the presence of the rough yeast, the discrepancy between fructose and glucose concentrations were markedly higher, especially in molasses. The biggest problem associated with incomplete fermentation seemed to be the lower consumption rate of sugar and the reduced fructose preference of the rough yeast rather than the lower invertase activity. Lower ethanol production, acetate production and higher residual sugar concentration are characteristics strongly associated with the rough yeast strain and they were not potentiated with the inoculation of L. fermentum.

Brewing Science in the Chemistry Laboratory: A "Mashing" Investigation of Starch and Carbohydrates

Science.gov (United States)

Pelter, Michael W.; McQuade, Jennifer

2005-01-01

The experiments that mimic the actual brewing process to explain the science to the nonscience majors is performed using malted barley as the source for both the starch and the amylase enzyme. The experiment introduces the concept of monitoring the progress of chemical reaction and was able to show the chemical breakdown of the starch to simple…

Impact of the brewing process on the concentration of silicon in lager beer

Czech Academy of Sciences Publication Activity Database

Krausová, Ivana; Cejnar, R.; Kučera, Jan; Dostálek, P.

2014-01-01

Roč. 120, č. 4 (2014), s. 433-437 ISSN 0046-9750 R&D Projects: GA MŠk 1M0570; GA MŠk(XE) LM2011019; GA ČR(CZ) GBP108/12/G108 Institutional support: RVO:61389005 Keywords : beer * brewing * hops * INAA * malt * silicon Subject RIV: GM - Food Processing Impact factor: 1.240, year: 2014

Systems Biology for Mapping Genotype-Phenotype Relations in Yeast

KAUST Repository

Nielsen, Jens

2016-01-25

The yeast Saccharomyces cerevisiae is widely used for production of fuels, chemicals, pharmaceuticals and materials. Through metabolic engineering of this yeast a number of novel new industrial processes have been developed over the last 10 years. Besides its wide industrial use, S. cerevisiae serves as an eukaryal model organism, and many systems biology tools have therefore been developed for this organism. Among these genome-scale metabolic models have shown to be most successful as they easy integrate with omics data and at the same time have been shown to have excellent predictive power. Despite our extensive knowledge of yeast metabolism and its regulation we are still facing challenges when we want to engineer complex traits, such as improved tolerance to toxic metabolites like butanol and elevated temperatures or when we want to engineer the highly complex protein secretory pathway. In this presentation it will be demonstrated how we can combine directed evolution with systems biology analysis to identify novel targets for rational design-build-test of yeast strains that have improved phenotypic properties. In this lecture an overview of systems biology of yeast will be presented together with examples of how genome-scale metabolic modeling can be used for prediction of cellular growth at different conditions. Examples will also be given on how adaptive laboratory evolution can be used for identifying targets for improving tolerance towards butanol, increased temperature and low pH and for improving secretion of heterologous proteins.

Kazachstania gamospora and Wickerhamomyces subpelliculosus : Two alternative baker's yeasts in the modern bakery

NARCIS (Netherlands)

Zhou, Nerve; Judith Schifferdecker, Anna; Gamero Lluna, Amparo; Compagno, Concetta; Boekhout, Teun; Piškur, Jure; Knecht, Wolfgang

2017-01-01

Saccharomyces cerevisiae, the conventional baker's yeast, remains the most domesticated yeast monopolizing the baking industry. Its rapid consumption of sugars and production of CO2 are the most important attributes required to leaven the dough. New research attempts highlight that these attributes

Genetic manipulation of amylotic yeast for degradation of starch

International Nuclear Information System (INIS)

Nasim, A.

1991-01-01

The availability of a variety of techniques in Genetic Engineering has greatly facilitated the manipulation of hereditary material. These methodologies provide effective tools to utilize the existing microorganisms for creating novel combinations of hybrid strains for the degradation of substrates that can be converted into alcohol. Yeasts have several distinct advantages including the long standing industrial experience of scaling up the growth. The present report deals with the account of some experimental approaches used to obtained amylolytic yeast strains with ability to degrade starch. From among the naturally occurring yeasts schwanniomyces was found to be very efficient for this purpose. Both gene cloning and protoplast fusion were used to transfer DNA from Saccharomyces diastaticus to the bakers yeast Saccharomyces cerevisiae. The glucoamylase gene of S. diastaticus has been successfully cloned into S. cerevisiae. The observations are discussed as there relate to the current efforts to degrade substrates for energy placing special emphasis on the tremendous potential that naturally occurring microbes may have. This emphasizes the need to examine this aspect critically before initiating attempts to genetically engineer microbes for heterologous gene transfer, which appears to have serious limitations as far as the production of the end products adequate for industrial purposes are concerned. (author)

Introducing a new breed of wine yeast: interspecific hybridisation between a commercial Saccharomyces cerevisiae wine yeast and Saccharomyces mikatae.

Directory of Open Access Journals (Sweden)

Jennifer R Bellon

Full Text Available Interspecific hybrids are commonplace in agriculture and horticulture; bread wheat and grapefruit are but two examples. The benefits derived from interspecific hybridisation include the potential of generating advantageous transgressive phenotypes. This paper describes the generation of a new breed of wine yeast by interspecific hybridisation between a commercial Saccharomyces cerevisiae wine yeast strain and Saccharomyces mikatae, a species hitherto not associated with industrial fermentation environs. While commercially available wine yeast strains provide consistent and reliable fermentations, wines produced using single inocula are thought to lack the sensory complexity and rounded palate structure obtained from spontaneous fermentations. In contrast, interspecific yeast hybrids have the potential to deliver increased complexity to wine sensory properties and alternative wine styles through the formation of novel, and wider ranging, yeast volatile fermentation metabolite profiles, whilst maintaining the robustness of the wine yeast parent. Screening of newly generated hybrids from a cross between a S. cerevisiae wine yeast and S. mikatae (closely-related but ecologically distant members of the Saccharomyces sensu stricto clade, has identified progeny with robust fermentation properties and winemaking potential. Chemical analysis showed that, relative to the S. cerevisiae wine yeast parent, hybrids produced wines with different concentrations of volatile metabolites that are known to contribute to wine flavour and aroma, including flavour compounds associated with non-Saccharomyces species. The new S. cerevisiae x S. mikatae hybrids have the potential to produce complex wines akin to products of spontaneous fermentation while giving winemakers the safeguard of an inoculated ferment.

Introducing a New Breed of Wine Yeast: Interspecific Hybridisation between a Commercial Saccharomyces cerevisiae Wine Yeast and Saccharomyces mikatae

Science.gov (United States)

Bellon, Jennifer R.; Schmid, Frank; Capone, Dimitra L.; Dunn, Barbara L.; Chambers, Paul J.

2013-01-01

Interspecific hybrids are commonplace in agriculture and horticulture; bread wheat and grapefruit are but two examples. The benefits derived from interspecific hybridisation include the potential of generating advantageous transgressive phenotypes. This paper describes the generation of a new breed of wine yeast by interspecific hybridisation between a commercial Saccharomyces cerevisiae wine yeast strain and Saccharomyces mikatae, a species hitherto not associated with industrial fermentation environs. While commercially available wine yeast strains provide consistent and reliable fermentations, wines produced using single inocula are thought to lack the sensory complexity and rounded palate structure obtained from spontaneous fermentations. In contrast, interspecific yeast hybrids have the potential to deliver increased complexity to wine sensory properties and alternative wine styles through the formation of novel, and wider ranging, yeast volatile fermentation metabolite profiles, whilst maintaining the robustness of the wine yeast parent. Screening of newly generated hybrids from a cross between a S. cerevisiae wine yeast and S. mikatae (closely-related but ecologically distant members of the Saccharomyces sensu stricto clade), has identified progeny with robust fermentation properties and winemaking potential. Chemical analysis showed that, relative to the S. cerevisiae wine yeast parent, hybrids produced wines with different concentrations of volatile metabolites that are known to contribute to wine flavour and aroma, including flavour compounds associated with non-Saccharomyces species. The new S. cerevisiae x S. mikatae hybrids have the potential to produce complex wines akin to products of spontaneous fermentation while giving winemakers the safeguard of an inoculated ferment. PMID:23614011

Genetic and phenotypic characteristics of baker's yeast: relevance to baking.

Science.gov (United States)

Randez-Gil, Francisca; Córcoles-Sáez, Isaac; Prieto, José A

2013-01-01

Yeasts rarely encounter ideal physiological conditions during their industrial life span; therefore, their ability to adapt to changing conditions determines their usefulness and applicability. This is especially true for baking strains of Saccharomyces cerevisiae. The success of this yeast in the ancient art of bread making is based on its capacity to rapidly transform carbohydrates into CO2 rather than its unusual resistance to environmental stresses. Moreover, baker's yeast must exhibit efficient respiratory metabolism during yeast manufacturing, which determines biomass yield. However, optimal growth conditions often have negative consequences in other commercially important aspects, such as fermentative power or stress tolerance. This article reviews the genetic and physiological characteristics of baking yeast strains, emphasizing the activation of regulatory mechanisms in response to carbon source and stress signaling and their importance in defining targets for strain selection and improvement.

Nuclear Magnetic Resonance Spectroscopy-Based Identification of Yeast.

Science.gov (United States)

Himmelreich, Uwe; Sorrell, Tania C; Daniel, Heide-Marie

2017-01-01

Rapid and robust high-throughput identification of environmental, industrial, or clinical yeast isolates is important whenever relatively large numbers of samples need to be processed in a cost-efficient way. Nuclear magnetic resonance (NMR) spectroscopy generates complex data based on metabolite profiles, chemical composition and possibly on medium consumption, which can not only be used for the assessment of metabolic pathways but also for accurate identification of yeast down to the subspecies level. Initial results on NMR based yeast identification where comparable with conventional and DNA-based identification. Potential advantages of NMR spectroscopy in mycological laboratories include not only accurate identification but also the potential of automated sample delivery, automated analysis using computer-based methods, rapid turnaround time, high throughput, and low running costs.We describe here the sample preparation, data acquisition and analysis for NMR-based yeast identification. In addition, a roadmap for the development of classification strategies is given that will result in the acquisition of a database and analysis algorithms for yeast identification in different environments.

Induction of ploidy level increments in an asporogenous industrial strain of the yeast Saccaromyces cerevisiae by UV irradiation

International Nuclear Information System (INIS)

Sasaki, Takashi

1992-01-01

Cells of an asporogenous industrial strain of the yeast Saccaromyces cerevisiae were irradiated with UV light by using a method that was developed previously. This treatment gave rise to large-cell clones among the surviving cells, from which colonies consisting of cells with a normal morphology and a prototropic property were obtained. The large-cell trait of these was stably inheritable, with the cell volumes being about twice that of the parent for 7 years on a slant agar medium at 4C with repeated transfers. The cellular DNA content of these clones, in comparison to those of two authentic haploid strains, was determined by chemical analysis. The ratio of the DNA contents showed that the parent and its large-cell derivatives were a diploid and tetraploids, respectively. No abnormality was found in the chromosomal DNA patterns of the large-cell clones, at least as determined by agarose gel electrophoresis with a CHEF-DR II pulsed-field electrophoresis system. These findings led to the conclusion that the UV light method is applicable for inducing ploidy level increments in the widely used yeast species S. cerevisiae

Procedure of brewing alcohol as a staple food: case study of the fermented cereal liquor "Parshot" as a staple food in Dirashe special woreda, southern Ethiopia.

Science.gov (United States)

Sunano, Yui

2016-07-01

For most brews, alcohol fermentation and lactic fermentation take place simultaneously during the brewing process, and alcohol fermentation can progress smoothly because the propagation of various microorganisms is prevented by lactic fermentation. It is not necessary to cause lactic fermentation with a thing generated naturally and intentionally. The people living in the Dirashe area in southern Ethiopia drink three types of alcoholic beverages that are prepared from cereals. From these alcoholic beverages, parshot is prepared by the addition of plant leaves for lactic fermentation and nech chaka by adding cereal powder for lactic fermentation before alcohol fermentation. People living in the Dirashe area partake of parshot as part of their staple diet. The brewing process used for parshot and a food culture with alcoholic beverages as parts of the staple diet are rare worldwide. This article discusses the significance of using lactic fermentation before alcoholic fermentation and focuses on lactic fermentation in the brewing methods used for the three kinds of alcoholic beverages consumed in the Dirashe area. We initially observed the brewing process and obtained information about the process from the people in that area. Next, we determined the pH and analyzed the lactic acid (g/100 g) and ethanol (g/100 g) content during lactic fermentation of parshot and nech chaka; the ethyl acetate (mg/100 g) and volatile base nitrogen (mg/100 g) content during this period was also analyzed. In addition, we compared the ethanol (g/100 g) content of all three kinds of alcoholic beverages after completion of brewing. The results showed that it was possible to consume large quantities of these alcoholic beverages because of the use of lactic fermentation before alcoholic fermentation, which improved the safety and preservation characteristics of the beverages by preventing the propagation of various microorganisms, improving flavor, and controlling the alcohol level.

Genetic engineering of industrial Saccharomyces cerevisiae strains using a selection/counter-selection approach.

Science.gov (United States)

Kutyna, Dariusz R; Cordente, Antonio G; Varela, Cristian

2014-01-01

Gene modification of laboratory yeast strains is currently a very straightforward task thanks to the availability of the entire yeast genome sequence and the high frequency with which yeast can incorporate exogenous DNA into its genome. Unfortunately, laboratory strains do not perform well in industrial settings, indicating the need for strategies to modify industrial strains to enable strain development for industrial applications. Here we describe approaches we have used to genetically modify industrial strains used in winemaking.

Determination of Pyrethroids in Tea Brew by GC-MS Combined with SPME with Multiwalled Carbon Nanotube Coated Fiber

Directory of Open Access Journals (Sweden)

Dongxia Ren

2018-01-01

Full Text Available A new method has been developed to simultaneously determine 7 pyrethroid residues in tea brew using gas chromatography-mass spectrometry (GC-MS combined with solid phase microextraction (SPME with multiwalled carbon nanotubes (MWCNTs coated fiber. The MWCNTs coated fiber of SPME was homemade by using stainless steel wire as coating carrier and polyacrylonitrile (PAN solution as adhesive glue. Under the optimized conditions, a good linearity was shown for bifenthrin, fenpropathrin, permethrin, and cyfluthrin in 1–50 ng mL−1 and for cypermethrin, fenvalerate, and deltamethrin in 5–50 ng mL−1. The correlation coefficients were in the range of 0.9948–0.9999. The average recoveries of 7 pyrethroids were 94.2%–107.3% and the relative standard deviations (RSDs were less than 15%. The detection limit of the method ranged from 0.12 to 1.65 ng mL−1. The tea brew samples made from some commercial tea samples were analyzed. Among them, bifenthrin, fenpropathrin, and permethrin were found. The results show that the method is rapid and sensitive and requires low organic reagent consumption, which can be well used for the detection of the pyrethroids in tea brew.

Screening and characterizing of xylanolytic and xylose-fermenting yeasts isolated from the wood-feeding termite, Reticulitermes chinensis.

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Sameh Samir Ali

Full Text Available The effective fermentation of xylose remains an intractable challenge in bioethanol industry. The relevant xylanase enzyme is also in a high demand from industry for several biotechnological applications that inevitably in recent times led to many efforts for screening some novel microorganisms for better xylanase production and fermentation performance. Recently, it seems that wood-feeding termites can truly be considered as highly efficient natural bioreactors. The highly specialized gut systems of such insects are not yet fully realized, particularly, in xylose fermentation and xylanase production to advance industrial bioethanol technology as well as industrial applications of xylanases. A total of 92 strains from 18 yeast species were successfully isolated and identified from the gut of wood-feeding termite, Reticulitermes chinensis. Of these yeasts and strains, seven were identified for new species: Candida gotoi, Candida pseudorhagii, Hamamotoa lignophila, Meyerozyma guilliermondii, Sugiyamaella sp.1, Sugiyamaella sp. 2, and Sugiyamaella sp.3. Based on the phylogenetic and phenotypic characterization, the type strain of C. pseudorhagii sp. nov., which was originally designated strain SSA-1542T, was the most frequently occurred yeast from termite gut samples, showed the highly xylanolytic activity as well as D-xylose fermentation. The highest xylanase activity was recorded as 1.73 and 0.98 U/mL with xylan or D-xylose substrate, respectively, from SSA-1542T. Among xylanase-producing yeasts, four novel species were identified as D-xylose-fermenting yeasts, where the yeast, C. pseudorhagii SSA-1542T, showed the highest ethanol yield (0.31 g/g, ethanol productivity (0.31 g/L·h, and its fermentation efficiency (60.7% in 48 h. Clearly, the symbiotic yeasts isolated from termite guts have demonstrated a competitive capability to produce xylanase and ferment xylose, suggesting that the wood-feeding termite gut is a promising reservoir for novel

Production of ethanol and polyethanol by yeasts isolated from date ...

African Journals Online (AJOL)

Linda

valuation by biotechnological processes enables the production of high value added materials with low cost. In this regard, the objective of this study focused on the selection of yeasts ... produce ethyl alcohol from this waste used in many industries and ... fundamental economic interest. ..... Industrial enzymes from marine.

Lead poisoning from drinking Kombucha tea brewed in a ceramic pot.

Science.gov (United States)

Phan, T G; Estell, J; Duggin, G; Beer, I; Smith, D; Ferson, M J

Kombucha tea is an alternative therapy that is gaining popularity as a remedy for a diverse range of ailments. We report two cases of symptomatic lead poisoning requiring chelation therapy in a married couple who had been drinking Kombucha tea for six months, brewing the tea in a ceramic pot. We postulate that acids in the tea eluted lead from the glaze pigment used in the ceramic pot, in a manner analogous to elution of lead from crystal decanters by wine and spirits.

Genome-wide analytical approaches for reverse metabolic engineering of industrially relevant phenotypes in yeast

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Oud, Bart; Maris, Antonius J A; Daran, Jean-Marc; Pronk, Jack T

2012-01-01

Successful reverse engineering of mutants that have been obtained by nontargeted strain improvement has long presented a major challenge in yeast biotechnology. This paper reviews the use of genome-wide approaches for analysis of Saccharomyces cerevisiae strains originating from evolutionary engineering or random mutagenesis. On the basis of an evaluation of the strengths and weaknesses of different methods, we conclude that for the initial identification of relevant genetic changes, whole genome sequencing is superior to other analytical techniques, such as transcriptome, metabolome, proteome, or array-based genome analysis. Key advantages of this technique over gene expression analysis include the independency of genome sequences on experimental context and the possibility to directly and precisely reproduce the identified changes in naive strains. The predictive value of genome-wide analysis of strains with industrially relevant characteristics can be further improved by classical genetics or simultaneous analysis of strains derived from parallel, independent strain improvement lineages. PMID:22152095

Genome-wide analytical approaches for reverse metabolic engineering of industrially relevant phenotypes in yeast.

Science.gov (United States)

Oud, Bart; van Maris, Antonius J A; Daran, Jean-Marc; Pronk, Jack T

2012-03-01

Successful reverse engineering of mutants that have been obtained by nontargeted strain improvement has long presented a major challenge in yeast biotechnology. This paper reviews the use of genome-wide approaches for analysis of Saccharomyces cerevisiae strains originating from evolutionary engineering or random mutagenesis. On the basis of an evaluation of the strengths and weaknesses of different methods, we conclude that for the initial identification of relevant genetic changes, whole genome sequencing is superior to other analytical techniques, such as transcriptome, metabolome, proteome, or array-based genome analysis. Key advantages of this technique over gene expression analysis include the independency of genome sequences on experimental context and the possibility to directly and precisely reproduce the identified changes in naive strains. The predictive value of genome-wide analysis of strains with industrially relevant characteristics can be further improved by classical genetics or simultaneous analysis of strains derived from parallel, independent strain improvement lineages. © 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

Potential for energy-conserving capital equipment in UK industries

Energy Technology Data Exchange (ETDEWEB)

Fawkes, S D

1986-01-01

A summary is given of recent research into the potential for energy-conserving capital equipment in UK industries. The research had significant findings regarding the feasibility of achieving low-energy scenarios. It also stressed the importance of site specific factors in inhibiting incremental technical change such as that common in energy-conservation investments, developed a soft systems model of energy-management activities and investigated current progress and management styles in the brewing, malting, distilling and dairy sectors.

Survival of Salmonella on chamomile, peppermint, and green tea during storage and subsequent survival or growth following tea brewing.

Science.gov (United States)

Keller, Susanne E; Stam, Christina N; Gradl, Dana R; Chen, Zhengzai; Larkin, Emily L; Pickens, Shannon R; Chirtel, Stuart J

2015-04-01

The survival of Salmonella on dried chamomile flowers, peppermint leaves, and green tea leaves stored under different conditions was examined. Survival and growth of Salmonella was also assessed after subsequent brewing using dried inoculated teas. A Salmonella enterica serovar cocktail was inoculated onto different dried tea leaves or flowers to give starting populations of approximately 10 log CFU/g. The inoculum was allowed to dry (at ambient temperature for 24 h) onto the dried leaves or flowers prior to storage under 25 and 35 °C at low (90% RH) humidity levels. Under the four storage conditions tested, survival followed the order 25 °C with low RH > 35 °C with low RH > 25 °C with high RH > 35 °C with high RH. Salmonella losses at 25 °C with low RH occurred primarily during drying, after which populations showed little decline over 6 months. In contrast, Salmonella decreased below detection after 45 days at 35 °C and high RH in all teas tested. The thermal resistance of Salmonella was assessed at 55 °C immediately after inoculation of tea leaves or flowers, after drying (24 h) onto tea leaves or flowers, and after 28 days of storage at 25 °C with low RH. All conditions resulted in similar D-values (2.78 ± 0.12, 3.04 ± 0.07, and 2.78 ± 0.56, at 0 h, 24 h, and 28 days, respectively), indicating thermal resistance of Salmonella in brewed tea did not change after desiccation and 28 days of storage. In addition, all brewed teas tested supported the growth of Salmonella. If Salmonella survives after storage, it may also survive and grow after a home brewing process.

Co-Flocculation of Yeast Species, a New Mechanism to Govern Population Dynamics in Microbial Ecosystems.

Directory of Open Access Journals (Sweden)

Debra Rossouw

Full Text Available Flocculation has primarily been studied as an important technological property of Saccharomyces cerevisiae yeast strains in fermentation processes such as brewing and winemaking. These studies have led to the identification of a group of closely related genes, referred to as the FLO gene family, which controls the flocculation phenotype. All naturally occurring S. cerevisiae strains assessed thus far possess at least four independent copies of structurally similar FLO genes, namely FLO1, FLO5, FLO9 and FLO10. The genes appear to differ primarily by the degree of flocculation induced by their expression. However, the reason for the existence of a large family of very similar genes, all involved in the same phenotype, has remained unclear. In natural ecosystems, and in wine production, S. cerevisiae growth together and competes with a large number of other Saccharomyces and many more non-Saccharomyces yeast species. Our data show that many strains of such wine-related non-Saccharomyces species, some of which have recently attracted significant biotechnological interest as they contribute positively to fermentation and wine character, were able to flocculate efficiently. The data also show that both flocculent and non-flocculent S. cerevisiae strains formed mixed species flocs (a process hereafter referred to as co-flocculation with some of these non-Saccharomyces yeasts. This ability of yeast strains to impact flocculation behaviour of other species in mixed inocula has not been described previously. Further investigation into the genetic regulation of co-flocculation revealed that different FLO genes impact differently on such adhesion phenotypes, favouring adhesion with some species while excluding other species from such mixed flocs. The data therefore strongly suggest that FLO genes govern the selective association of S. cerevisiae with specific species of non-Saccharomyces yeasts, and may therefore be drivers of ecosystem organisational

Yeast synthetic biology for the production of recombinant therapeutic proteins.

Science.gov (United States)

Kim, Hyunah; Yoo, Su Jin; Kang, Hyun Ah

2015-02-01

The production of recombinant therapeutic proteins is one of the fast-growing areas of molecular medicine and currently plays an important role in treatment of several diseases. Yeasts are unicellular eukaryotic microbial host cells that offer unique advantages in producing biopharmaceutical proteins. Yeasts are capable of robust growth on simple media, readily accommodate genetic modifications, and incorporate typical eukaryotic post-translational modifications. Saccharomyces cerevisiae is a traditional baker's yeast that has been used as a major host for the production of biopharmaceuticals; however, several nonconventional yeast species including Hansenula polymorpha, Pichia pastoris, and Yarrowia lipolytica have gained increasing attention as alternative hosts for the industrial production of recombinant proteins. In this review, we address the established and emerging genetic tools and host strains suitable for recombinant protein production in various yeast expression systems, particularly focusing on current efforts toward synthetic biology approaches in developing yeast cell factories for the production of therapeutic recombinant proteins. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permission@oup.com.

Yeast species associated with wine grapes in China.

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Li, Shuang-Shi; Cheng, Chao; Li, Zheng; Chen, Jing-Yu; Yan, Bin; Han, Bei-Zhong; Reeves, Malcolm

2010-03-31

Having more information on the yeast ecology of grapes is important for wine-makers to produce wine with high quality and typical attributes. China is a significant wine-consuming country and is becoming a serious wine-producer, but little has been reported about the yeast ecology of local ecosystems. This study provides the first step towards the exploitation of the yeast wealth in China's vine-growing regions. The aim of this study was to investigate the yeast population density and diversity on three grape varieties cultivated in four representative vine-growing regions of China. Yeast species diversity was evaluated by using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and sequence analysis of the 5.8S internal transcribed spacer (ITS) ribosomal DNA (rDNA) region of cultivable yeasts. The grapes harbored yeast populations at 10(2)-10(6)CFU/mL, consisting mostly of non-Saccharomyces species. Seventeen different yeast species belonging to eight genera were detected on the grape samples tested, including Hanseniaspora uvarum, Cryptococcus flavescens, Pichia fermentans, Candida zemplinina, Cryptococcus carnescens, Candida inconpicua, Zygosaccharomyces fermentati, Issatchenkia terricola, Candida quercitrusa, Hanseniaspora guilliermondii, Candida bombi, Zygosaccharomyces bailii, Sporidiobolus pararoseus, Cryptococcus magnus, Metschnikowia pulcherrima, Issatchenkia orientalis and Pichia guilliermondii. H. uvarum and C. flavescens were the dominant species present on the grapes. For the first time Sporidiobolus pararoseus was discovered as an inhabitant of the grape ecosystem. The yeast community on grape berries was influenced by the grape chemical composition, vine-variety and vine-growing region. This study is the first to identify the yeast communities associated with grapes in China using molecular methods. The results enrich our knowledge of wine-related microorganisms, and can be used to promote the development of the local wine

Optimization of carbon and nitrogen medium components for biomass production using non-Saccharomyces wine yeasts.

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Schnierda, T; Bauer, F F; Divol, B; van Rensburg, E; Görgens, J F

2014-05-01

The impact of different nitrogen and carbon sources on biomass production of the non-Saccharomyces wine yeast species Lachancea thermotolerans, Metschnikowia pulcherrima and Issatchenkia orientalis was assessed. Using a molasses-based medium, yeast extract and corn steep liquor as well as ammonium sulphate and di-ammonium phosphate (DAP) as nitrogen sources were compared in shake-flask cultures. A medium with 20 g l⁻¹ sugar (diluted molasses) and 500 mg l⁻¹ total yeast assimilable nitrogen, from yeast extract, gave the highest biomass concentrations and yields. Invertase pretreatment was required for cultures of M. pulcherrima and I. orientalis, and respective biomass yields of 0.7 and 0.8 g g⁻¹ were achieved in aerobic bioreactor cultures. The absence of ethanol production suggested Crabtree-negative behaviour by these yeasts, whereas Crabtree-positive behaviour by L. thermotolerans resulted in ethanol and biomass concentrations of 5.5 and 11.1 g l⁻¹, respectively. Recent studies demonstrate that non-Saccharomyces yeasts confer positive attributes to the final composition of wine. However, optimal process conditions for their biomass production have not been described, thereby limiting commercial application. In this study, industrial media and methods of yeast cultivation were investigated to develop protocols for biomass production of non-Saccharomyces yeast starter cultures for the wine industry. © 2014 The Society for Applied Microbiology.

De novo biosynthesis of vanillin in fission yeast (Schizosaccharomyces pombe) and baker's yeast (Saccharomyces cerevisiae).

Science.gov (United States)

Hansen, Esben H; Møller, Birger Lindberg; Kock, Gertrud R; Bünner, Camilla M; Kristensen, Charlotte; Jensen, Ole R; Okkels, Finn T; Olsen, Carl E; Motawia, Mohammed S; Hansen, Jørgen

2009-05-01

Vanillin is one of the world's most important flavor compounds, with a global market of 180 million dollars. Natural vanillin is derived from the cured seed pods of the vanilla orchid (Vanilla planifolia), but most of the world's vanillin is synthesized from petrochemicals or wood pulp lignins. We have established a true de novo biosynthetic pathway for vanillin production from glucose in Schizosaccharomyces pombe, also known as fission yeast or African beer yeast, as well as in baker's yeast, Saccharomyces cerevisiae. Productivities were 65 and 45 mg/liter, after introduction of three and four heterologous genes, respectively. The engineered pathways involve incorporation of 3-dehydroshikimate dehydratase from the dung mold Podospora pauciseta, an aromatic carboxylic acid reductase (ACAR) from a bacterium of the Nocardia genus, and an O-methyltransferase from Homo sapiens. In S. cerevisiae, the ACAR enzyme required activation by phosphopantetheinylation, and this was achieved by coexpression of a Corynebacterium glutamicum phosphopantetheinyl transferase. Prevention of reduction of vanillin to vanillyl alcohol was achieved by knockout of the host alcohol dehydrogenase ADH6. In S. pombe, the biosynthesis was further improved by introduction of an Arabidopsis thaliana family 1 UDP-glycosyltransferase, converting vanillin into vanillin beta-D-glucoside, which is not toxic to the yeast cells and thus may be accumulated in larger amounts. These de novo pathways represent the first examples of one-cell microbial generation of these valuable compounds from glucose. S. pombe yeast has not previously been metabolically engineered to produce any valuable, industrially scalable, white biotech commodity.

Effect of brewing conditions on antioxidant properties of rosehip tea beverage: study by response surface methodology.

Science.gov (United States)

İlyasoğlu, Huri; Arpa, Tuba Eda

2017-10-01

The aim of this study was to investigate the effects of brewing conditions (infusion time and temperature) on the antioxidant properties of rosehip tea beverage. The ascorbic acid content, total phenolic content (TPC), and ferric reducing antioxidant power (FRAP) of rosehip tea beverage were analysed. A two-factor and three-level central composite design was applied to evaluate the effects of the variables on the responses. The best quadratic models were obtained for all responses. The generated models were validated under the optimal conditions. At the optimal conditions, the rosehip tea beverage had 3.15 mg 100 mL -1 of ascorbic acid, 61.44 mg 100 mL -1 of TPC, and 2591 µmol of FRAP. The best brewing conditions for the rosehip tea beverage were found to be an infusion time of 6-8 min at temperatures of 84-86 °C.

Outlining the influence of non-conventional yeasts in wine ageing over lees.

Science.gov (United States)

Belda, Ignacio; Navascués, Eva; Marquina, Domingo; Santos, Antonio; Calderón, Fernando; Benito, Santiago

2016-07-01

During the last decade, the use of innovative yeast cultures of both Saccharomyces cerevisiae and non-Saccharomyces yeasts as alternative tools to manage the winemaking process have turned the oenology industry. Although the contribution of different yeast species to wine quality during fermentation is increasingly understood, information about their role in wine ageing over lees is really scarce. This work aims to analyse the incidence of three non-Saccharomyces yeast species of oenological interest (Torulaspora delbrueckii, Lachancea thermotolerans and Metschnikowia pulcherrima) and of a commercial mannoprotein-overproducer S. cerevisiae strain compared with a conventional industrial yeast strain during wine ageing over lees. To evaluate their incidence in mouthfeel properties of wine after 4 months of ageing, the mannoprotein content of wines was evaluated, together with other wine analytic parameters, such as colour and aroma, biogenic amines and amino acids profile. Some differences among the studied parameters were observed during the study, especially regarding the mannoprotein concentration of wines. Our results suggest that the use of T. delbrueckii lees in wine ageing is a useful tool for the improvement of overall wine quality by notably increasing mannoproteins, reaching values higher than obtained using a S. cerevisiae overproducer strain. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Transcriptional Regulation and the Diversification of Metabolism in Wine Yeast Strains

Science.gov (United States)

Rossouw, Debra; Jacobson, Dan; Bauer, Florian F.

2012-01-01

Transcription factors and their binding sites have been proposed as primary targets of evolutionary adaptation because changes to single transcription factors can lead to far-reaching changes in gene expression patterns. Nevertheless, there is very little concrete evidence for such evolutionary changes. Industrial wine yeast strains, of the species Saccharomyces cerevisiae, are a geno- and phenotypically diverse group of organisms that have adapted to the ecological niches of industrial winemaking environments and have been selected to produce specific styles of wine. Variation in transcriptional regulation among wine yeast strains may be responsible for many of the observed differences and specific adaptations to different fermentative conditions in the context of commercial winemaking. We analyzed gene expression profiles of wine yeast strains to assess the impact of transcription factor expression on metabolic networks. The data provide new insights into the molecular basis of variations in gene expression in industrial strains and their consequent effects on metabolic networks important to wine fermentation. We show that the metabolic phenotype of a strain can be shifted in a relatively predictable manner by changing expression levels of individual transcription factors, opening opportunities to modify transcription networks to achieve desirable outcomes. PMID:22042577

Production of ethanol from cassava pulp via fermentation with a surface-engineered yeast strain displaying glucoamylase

Energy Technology Data Exchange (ETDEWEB)

Kosugi, Akihiko; Murata, Yoshinori; Arai, Takamitsu; Mori, Yutaka [Post-harvest Science and Technology Division, Japan International Research Center for Agricultural Sciences (JIRCAS), 1-1 Ohwashi, Tsukuba, Ibaraki 305-8686 (Japan); Kondo, Akihiko [Department of Chemical Science and Engineering, Faculty of Engineering, Kobe University, Nada-ku, Kobe, 657-8501 (Japan); Ueda, Mitsuyoshi [Department of Applied Biochemistry, Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto 606-8502 (Japan); Vaithanomsat, Pilanee; Thanapase, Warunee [Nanotechnology and Biotechnology Division, Kasetsart Agricultural and Agro-Industrial Product Improvement Institute (KAPI), Kasetsart University, 50 Chatuchak, Ladyao, Bangkok 10900 (Thailand)

2009-05-15

Cassava (Manihot esculenta Crantz) pulp, produced in large amounts as a by-product of starch manufacturing, is a major biomass resource in Southeast Asian countries. It contains abundant starch (approximately 60%) and cellulose fiber (approximately 20%). To effectively utilize the cassava pulp, an attempt was made to convert its components to ethanol using a sake-brewing yeast displaying glucoamylase on the cell surface. Saccharomyces cerevisiae Kyokai no. 7 (strain K7) displaying Rhizopus oryzae glucoamylase, designated strain K7G, was constructed using the C-terminal-half region of {alpha}-agglutinin. A sample of cassava pulp was pretreated with a hydrothermal reaction (140 C for 1 h), followed by treatment with a Trichoderma reesei cellulase to hydrolyze the cellulose in the sample. The K7G strain fermented starch and glucose in pretreated samples without addition of amylolytic enzymes, and produced ethanol in 91% and 80% of theoretical yield from 5% and 10% cassava pulp, respectively. (author)

Interactions between Drosophila and its natural yeast symbionts-Is Saccharomyces cerevisiae a good model for studying the fly-yeast relationship?

Science.gov (United States)

Hoang, Don; Kopp, Artyom; Chandler, James Angus

2015-01-01

Yeasts play an important role in the biology of the fruit fly, Drosophila melanogaster. In addition to being a valuable source of nutrition, yeasts affect D. melanogaster behavior and interact with the host immune system. Most experiments investigating the role of yeasts in D. melanogaster biology use the baker's yeast, Saccharomyces cerevisiae. However, S. cerevisiae is rarely found with natural populations of D. melanogaster or other Drosophila species. Moreover, the strain of S. cerevisiae used most often in D. melanogaster experiments is a commercially and industrially important strain that, to the best of our knowledge, was not isolated from flies. Since disrupting natural host-microbe interactions can have profound effects on host biology, the results from D. melanogaster-S. cerevisiae laboratory experiments may not be fully representative of host-microbe interactions in nature. In this study, we explore the D. melanogaster-yeast relationship using five different strains of yeast that were isolated from wild Drosophila populations. Ingested live yeasts have variable persistence in the D. melanogaster gastrointestinal tract. For example, Hanseniaspora occidentalis persists relative to S. cerevisiae, while Brettanomyces naardenensis is removed. Despite these differences in persistence relative to S. cerevisiae, we find that all yeasts decrease in total abundance over time. Reactive oxygen species (ROS) are an important component of the D. melanogaster anti-microbial response and can inhibit S. cerevisiae growth in the intestine. To determine if sensitivity to ROS explains the differences in yeast persistence, we measured yeast growth in the presence and absence of hydrogen peroxide. We find that B. naardenesis is completely inhibited by hydrogen peroxide, while H. occidentalis is not, which is consistent with yeast sensitivity to ROS affecting persistence within the D. melanogaster gastrointestinal tract. We also compared the feeding preference of D

Synthetic yeast based cell factories for vanillin-glucoside production

DEFF Research Database (Denmark)

Strucko, Tomas

and controlled expression/overexpression of genes of interest. De novo biosynthetic pathway for vanillin-β-glucoside production was employed as a model system for several case studies in this project. In order to construct yeast cell factories fulfilling current demands of industrial biotechnology, methods......The yeast Saccharomyces cerevisiae is well a characterized microorganism and widely used as eukaryotic model organism as well as a key cell factory for bioproduction of various products. The latter comprise a large variety of scientifically and industrially relevant products such as low-value bulk...... chemicals and biofuels, food additives, high-value chemicals and recombinant proteins. Despite the recent achievements in the fields of systems biology and metabolic engineering together with availability of broad genetic engineering toolbox, the full potential of S. cerevisiae as a cell factory is not yet...

Rapid, portable and cost-effective yeast cell viability and concentration analysis using lensfree on-chip microscopy and machine learning

KAUST Repository

Feizi, Alborz

2016-09-24

Monitoring yeast cell viability and concentration is important in brewing, baking and biofuel production. However, existing methods of measuring viability and concentration are relatively bulky, tedious and expensive. Here we demonstrate a compact and cost-effective automatic yeast analysis platform (AYAP), which can rapidly measure cell concentration and viability. AYAP is based on digital in-line holography and on-chip microscopy and rapidly images a large field-of-view of 22.5 mm2. This lens-free microscope weighs 70 g and utilizes a partially-coherent illumination source and an opto-electronic image sensor chip. A touch-screen user interface based on a tablet-PC is developed to reconstruct the holographic shadows captured by the image sensor chip and use a support vector machine (SVM) model to automatically classify live and dead cells in a yeast sample stained with methylene blue. In order to quantify its accuracy, we varied the viability and concentration of the cells and compared AYAP\\'s performance with a fluorescence exclusion staining based gold-standard using regression analysis. The results agree very well with this gold-standard method and no significant difference was observed between the two methods within a concentration range of 1.4 × 105 to 1.4 × 106 cells per mL, providing a dynamic range suitable for various applications. This lensfree computational imaging technology that is coupled with machine learning algorithms would be useful for cost-effective and rapid quantification of cell viability and density even in field and resource-poor settings.

Rapid, portable and cost-effective yeast cell viability and concentration analysis using lensfree on-chip microscopy and machine learning.

Science.gov (United States)

Feizi, Alborz; Zhang, Yibo; Greenbaum, Alon; Guziak, Alex; Luong, Michelle; Chan, Raymond Yan Lok; Berg, Brandon; Ozkan, Haydar; Luo, Wei; Wu, Michael; Wu, Yichen; Ozcan, Aydogan

2016-11-01

Monitoring yeast cell viability and concentration is important in brewing, baking and biofuel production. However, existing methods of measuring viability and concentration are relatively bulky, tedious and expensive. Here we demonstrate a compact and cost-effective automatic yeast analysis platform (AYAP), which can rapidly measure cell concentration and viability. AYAP is based on digital in-line holography and on-chip microscopy and rapidly images a large field-of-view of 22.5 mm 2 . This lens-free microscope weighs 70 g and utilizes a partially-coherent illumination source and an opto-electronic image sensor chip. A touch-screen user interface based on a tablet-PC is developed to reconstruct the holographic shadows captured by the image sensor chip and use a support vector machine (SVM) model to automatically classify live and dead cells in a yeast sample stained with methylene blue. In order to quantify its accuracy, we varied the viability and concentration of the cells and compared AYAP's performance with a fluorescence exclusion staining based gold-standard using regression analysis. The results agree very well with this gold-standard method and no significant difference was observed between the two methods within a concentration range of 1.4 × 10 5 to 1.4 × 10 6 cells per mL, providing a dynamic range suitable for various applications. This lensfree computational imaging technology that is coupled with machine learning algorithms would be useful for cost-effective and rapid quantification of cell viability and density even in field and resource-poor settings.

Efficient screening of environmental isolates for Saccharomyces cerevisiae strains that are suitable for brewing.

Science.gov (United States)

Fujihara, Hidehiko; Hino, Mika; Takashita, Hideharu; Kajiwara, Yasuhiro; Okamoto, Keiko; Furukawa, Kensuke

2014-01-01

We developed an efficient screening method for Saccharomyces cerevisiae strains from environmental isolates. MultiPlex PCR was performed targeting four brewing S. cerevisiae genes (SSU1, AWA1, BIO6, and FLO1). At least three genes among the four were amplified from all S. cerevisiae strains. The use of this method allowed us to successfully obtain S. cerevisiae strains.

Under pressure: evolutionary engineering of yeast strains for improved performance in fuels and chemicals production.

Science.gov (United States)

Mans, Robert; Daran, Jean-Marc G; Pronk, Jack T

2018-04-01

Evolutionary engineering, which uses laboratory evolution to select for industrially relevant traits, is a popular strategy in the development of high-performing yeast strains for industrial production of fuels and chemicals. By integrating whole-genome sequencing, bioinformatics, classical genetics and genome-editing techniques, evolutionary engineering has also become a powerful approach for identification and reverse engineering of molecular mechanisms that underlie industrially relevant traits. New techniques enable acceleration of in vivo mutation rates, both across yeast genomes and at specific loci. Recent studies indicate that phenotypic trade-offs, which are often observed after evolution under constant conditions, can be mitigated by using dynamic cultivation regimes. Advances in research on synthetic regulatory circuits offer exciting possibilities to extend the applicability of evolutionary engineering to products of yeasts whose synthesis requires a net input of cellular energy. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

De Novo Biosynthesis of Vanillin in Fission Yeast (Schizosaccharomyces pombe) and Baker's Yeast (Saccharomyces cerevisiae) ▿

Science.gov (United States)

Hansen, Esben H.; Møller, Birger Lindberg; Kock, Gertrud R.; Bünner, Camilla M.; Kristensen, Charlotte; Jensen, Ole R.; Okkels, Finn T.; Olsen, Carl E.; Motawia, Mohammed S.; Hansen, Jørgen

2009-01-01

Vanillin is one of the world's most important flavor compounds, with a global market of 180 million dollars. Natural vanillin is derived from the cured seed pods of the vanilla orchid (Vanilla planifolia), but most of the world's vanillin is synthesized from petrochemicals or wood pulp lignins. We have established a true de novo biosynthetic pathway for vanillin production from glucose in Schizosaccharomyces pombe, also known as fission yeast or African beer yeast, as well as in baker's yeast, Saccharomyces cerevisiae. Productivities were 65 and 45 mg/liter, after introduction of three and four heterologous genes, respectively. The engineered pathways involve incorporation of 3-dehydroshikimate dehydratase from the dung mold Podospora pauciseta, an aromatic carboxylic acid reductase (ACAR) from a bacterium of the Nocardia genus, and an O-methyltransferase from Homo sapiens. In S. cerevisiae, the ACAR enzyme required activation by phosphopantetheinylation, and this was achieved by coexpression of a Corynebacterium glutamicum phosphopantetheinyl transferase. Prevention of reduction of vanillin to vanillyl alcohol was achieved by knockout of the host alcohol dehydrogenase ADH6. In S. pombe, the biosynthesis was further improved by introduction of an Arabidopsis thaliana family 1 UDP-glycosyltransferase, converting vanillin into vanillin β-d-glucoside, which is not toxic to the yeast cells and thus may be accumulated in larger amounts. These de novo pathways represent the first examples of one-cell microbial generation of these valuable compounds from glucose. S. pombe yeast has not previously been metabolically engineered to produce any valuable, industrially scalable, white biotech commodity. PMID:19286778

Non-Conventional Yeast Strains Increase the Aroma Complexity of Bread

Science.gov (United States)

Rezaei, Mohammad Naser; Steensels, Jan; Courtin, Christophe M.; Verstrepen, Kevin J.

2016-01-01

Saccharomyces cerevisiae is routinely used yeast in food fermentations because it combines several key traits, including fermentation efficiency and production of desirable flavors. However, the dominance of S. cerevisiae in industrial fermentations limits the diversity in the aroma profiles of the end products. Hence, there is a growing interest in non-conventional yeast strains that can help generate the diversity and complexity desired in today’s diversified and consumer-driven markets. Here, we selected a set of non-conventional yeast strains to examine their potential for bread fermentation. Here, we tested ten non-conventional yeasts for bread fermentation, including two Saccharomyces species that are not currently used in bread making and 8 non-Saccharomyces strains. The results show that Torulaspora delbrueckii and Saccharomyces bayanus combine satisfactory dough fermentation with an interesting flavor profile. Sensory analysis and HS-SPME-GC-MS analysis confirmed that these strains produce aroma profiles that are very different from that produced by a commercial bakery strain. Moreover, bread produced with these yeasts was preferred by a majority of a trained sensory panel. These results demonstrate the potential of T. delbrueckii and S. bayanus as alternative yeasts for bread dough leavening, and provide a general experimental framework for the evaluation of more yeasts and bacteria. PMID:27776154

Non-Conventional Yeast Strains Increase the Aroma Complexity of Bread.

Science.gov (United States)

Aslankoohi, Elham; Herrera-Malaver, Beatriz; Rezaei, Mohammad Naser; Steensels, Jan; Courtin, Christophe M; Verstrepen, Kevin J

2016-01-01

Saccharomyces cerevisiae is routinely used yeast in food fermentations because it combines several key traits, including fermentation efficiency and production of desirable flavors. However, the dominance of S. cerevisiae in industrial fermentations limits the diversity in the aroma profiles of the end products. Hence, there is a growing interest in non-conventional yeast strains that can help generate the diversity and complexity desired in today's diversified and consumer-driven markets. Here, we selected a set of non-conventional yeast strains to examine their potential for bread fermentation. Here, we tested ten non-conventional yeasts for bread fermentation, including two Saccharomyces species that are not currently used in bread making and 8 non-Saccharomyces strains. The results show that Torulaspora delbrueckii and Saccharomyces bayanus combine satisfactory dough fermentation with an interesting flavor profile. Sensory analysis and HS-SPME-GC-MS analysis confirmed that these strains produce aroma profiles that are very different from that produced by a commercial bakery strain. Moreover, bread produced with these yeasts was preferred by a majority of a trained sensory panel. These results demonstrate the potential of T. delbrueckii and S. bayanus as alternative yeasts for bread dough leavening, and provide a general experimental framework for the evaluation of more yeasts and bacteria.

Non-Conventional Yeast Strains Increase the Aroma Complexity of Bread.

Directory of Open Access Journals (Sweden)

Elham Aslankoohi

Full Text Available Saccharomyces cerevisiae is routinely used yeast in food fermentations because it combines several key traits, including fermentation efficiency and production of desirable flavors. However, the dominance of S. cerevisiae in industrial fermentations limits the diversity in the aroma profiles of the end products. Hence, there is a growing interest in non-conventional yeast strains that can help generate the diversity and complexity desired in today's diversified and consumer-driven markets. Here, we selected a set of non-conventional yeast strains to examine their potential for bread fermentation. Here, we tested ten non-conventional yeasts for bread fermentation, including two Saccharomyces species that are not currently used in bread making and 8 non-Saccharomyces strains. The results show that Torulaspora delbrueckii and Saccharomyces bayanus combine satisfactory dough fermentation with an interesting flavor profile. Sensory analysis and HS-SPME-GC-MS analysis confirmed that these strains produce aroma profiles that are very different from that produced by a commercial bakery strain. Moreover, bread produced with these yeasts was preferred by a majority of a trained sensory panel. These results demonstrate the potential of T. delbrueckii and S. bayanus as alternative yeasts for bread dough leavening, and provide a general experimental framework for the evaluation of more yeasts and bacteria.

Fast Moment Magnitude Determination from P-wave Trains for Bucharest Rapid Early Warning System (BREWS)

Science.gov (United States)

Lizurek, Grzegorz; Marmureanu, Alexandru; Wiszniowski, Jan

2017-03-01

Bucharest, with a population of approximately 2 million people, has suffered damage from earthquakes in the Vrancea seismic zone, which is located about 170 km from Bucharest, at a depth of 80-200 km. Consequently, an earthquake early warning system (Bucharest Rapid earthquake Early Warning System or BREWS) was constructed to provide some warning about impending shaking from large earthquakes in the Vrancea zone. In order to provide quick estimates of magnitude, seismic moment was first determined from P-waves and then a moment magnitude was determined from the moment. However, this magnitude may not be consistent with previous estimates of magnitude from the Romanian Seismic Network. This paper introduces the algorithm using P-wave spectral levels and compares them with catalog estimates. The testing procedure used waveforms from about 90 events with catalog magnitudes from 3.5 to 5.4. Corrections to the P-wave determined magnitudes according to dominant intermediate depth events mechanism were tested for November 22, 2014, M5.6 and October 17, M6 events. The corrections worked well, but unveiled overestimation of the average magnitude result of about 0.2 magnitude unit in the case of shallow depth event ( H < 60 km). The P-wave spectral approach allows for the relatively fast estimates of magnitude for use in BREWS. The average correction taking into account the most common focal mechanism for radiation pattern coefficient may lead to overestimation of the magnitude for shallow events of about 0.2 magnitude unit. However, in case of events of intermediate depth of M6 the resulting M w is underestimated at about 0.1-0.2. We conclude that our P-wave spectral approach is sufficiently robust for the needs of BREWS for both shallow and intermediate depth events.

Adding Flavor to Beverages with Non-Conventional Yeasts

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Davide Ravasio

2018-02-01

Full Text Available Fungi produce a variety of volatile organic compounds (VOCs during their primary and secondary metabolism. In the beverage industry, these volatiles contribute to the the flavor and aroma profile of the final products. We evaluated the fermentation ability and aroma profiles of non-conventional yeasts that have been associated with various food sources. A total of 60 strains were analyzed with regard to their fermentation and flavor profile. Species belonging to the genera Candida, Pichia and Wickerhamomyces separated best from lager yeast strains according to a principal component analysis taking alcohol and ester production into account. The speed of fermentation and sugar utilization were analysed for these strains. Volatile aroma-compound formation was assayed via gas chromatography. Several strains produced substantially higher amounts of aroma alcohols and esters compared to the lager yeast strain Weihenstephan 34/70. Consequently, co-fermentation of this lager yeast strain with a Wickerhamomyces anomalus strain generated an increased fruity-flavour profile. This demonstrates that mixed fermentations utilizing non-Saccharomyces cerevisiae biodiversity can enhance the flavour profiles of fermented beverages.

Antioxidant defense parameters as predictive biomarkers for fermentative capacity of active dried wine yeast.

Science.gov (United States)

Gamero-Sandemetrio, Esther; Gómez-Pastor, Rocío; Matallana, Emilia

2014-08-01

The production of active dried yeast (ADY) is a common practice in industry for the maintenance of yeast starters and as a means of long term storage. The process, however, causes multiple cell injuries, with oxidative damage being one of the most important stresses. Consequentially, dehydration tolerance is a highly appreciated property in yeast for ADY production. In this study we analyzed the cellular redox environment in three Saccharomyces cerevisiae wine strains, which show markedly different fermentative capacities after dehydration. To measure/quantify the effect of dehydration on the S. cerevisiae strains, we used: (i) fluorescent probes; (ii) antioxidant enzyme activities; (ii) intracellular damage; (iii) antioxidant metabolites; and (iv) gene expression, to select a minimal set of biochemical parameters capable of predicting desiccation tolerance in wine yeasts. Our results show that naturally enhanced antioxidant defenses prevent oxidative damage after wine yeast biomass dehydration and improve fermentative capacity. Based on these results we chose four easily assayable parameters/biomarkers for the selection of industrial yeast strains of interest for ADY production: trehalose and glutathione levels, and glutathione reductase and catalase enzymatic activities. Yeast strains selected in accordance with this process display high levels of trehalose, low levels of oxidized glutathione, a high induction of glutathione reductase activity, as well as a high basal level and sufficient induction of catalase activity, which are properties inherent in superior ADY strains. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Mitokondriyal Mutantların Bira Aroma Maddeleri Üzerine Etkisi

OpenAIRE

Tangüler, Hasan; Yağmur, Gülten; Erten, Hüseyin

2007-01-01

Brewer's yeast plays an important role on the production of flavour compounds. There are many organelles inside the cytoplasmic cell of brewers' yeast and mitochondrion is one of them. Mitochondrion consists of enzymes of tricarboxylic acid cycle and electron transport chain and therefore generates energy for cell. The most frequently identified spontaneously arising mutation in brewing yeast is mitochondrial mutation. Such mutations can range from partially mutations to com...

Production of biopharmaceutical proteins by yeast: Advances through metabolic engineering

DEFF Research Database (Denmark)

Nielsen, Jens

2013-01-01

Production of recombinant proteins for use as pharmaceuticals, so-called biopharmaceuticals, is a multi-billion dollar industry. Many different cell factories are used for the production of biopharmaceuticals, but the yeast Saccharomyces cerevisiae is an important cell factory as it is used for p...... production. The involvement of directed metabolic engineering through the integration of tools from genetic engineering, systems biology and mathematical modeling, is also discussed....... by yeast are human serum albumin, hepatitis vaccines and virus like particles used for vaccination against human papillomavirus. Here is given a brief overview of biopharmaceutical production by yeast and it is discussed how the secretory pathway can be engineered to ensure more efficient protein...

High-throughput screening of a large collection of non-conventional yeasts reveals their potential for aroma formation in food fermentation

NARCIS (Netherlands)

Gamero, Amparo; Quintilla, R.; Groenewald, Marizeth; Alkema, Wynand; Boekhout, Teun; Hazelwood, Lucie

2016-01-01

Saccharomyces yeast species are currently the most important yeasts involved in industrial-scale food fermentations. However, there are hundreds of other yeast species poorly studied that are highly promising for flavour development, some of which have also been identified in traditional food

Independent Evolution of Winner Traits without Whole Genome Duplication in Dekkera Yeasts.

Directory of Open Access Journals (Sweden)

Yi-Cheng Guo

Full Text Available Dekkera yeasts have often been considered as alternative sources of ethanol production that could compete with S. cerevisiae. The two lineages of yeasts independently evolved traits that include high glucose and ethanol tolerance, aerobic fermentation, and a rapid ethanol fermentation rate. The Saccharomyces yeasts attained these traits mainly through whole genome duplication approximately 100 million years ago (Mya. However, the Dekkera yeasts, which were separated from S. cerevisiae approximately 200 Mya, did not undergo whole genome duplication (WGD but still occupy a niche similar to S. cerevisiae. Upon analysis of two Dekkera yeasts and five closely related non-WGD yeasts, we found that a massive loss of cis-regulatory elements occurred in an ancestor of the Dekkera yeasts, which led to improved mitochondrial functions similar to the S. cerevisiae yeasts. The evolutionary analysis indicated that genes involved in the transcription and translation process exhibited faster evolution in the Dekkera yeasts. We detected 90 positively selected genes, suggesting that the Dekkera yeasts evolved an efficient translation system to facilitate adaptive evolution. Moreover, we identified that 12 vacuolar H+-ATPase (V-ATPase function genes that were under positive selection, which assists in developing tolerance to high alcohol and high sugar stress. We also revealed that the enzyme PGK1 is responsible for the increased rate of glycolysis in the Dekkera yeasts. These results provide important insights to understand the independent adaptive evolution of the Dekkera yeasts and provide tools for genetic modification promoting industrial usage.

Yeast cell wall chitin reduces wine haze formation.

Science.gov (United States)

Ndlovu, Thulile; Divol, Benoit; Bauer, Florian F

2018-04-27

Protein haze formation in bottled wines is a significant concern for the global wine industry and wine clarification before bottling is therefore a common but expensive practice. Previous studies have shown that wine yeast strains can reduce haze formation through the secretion of certain mannoproteins, but it has been suggested that other yeast-dependent haze protective mechanisms exist. On the other hand, addition of chitin has been shown to reduce haze formation, likely because grape chitinases have been shown to be the major contributors to haze. In this study, Chardonnay grape must fermented by various yeast strains resulted in wines with different protein haze levels indicating differences in haze protective capacities of the strains. The cell wall chitin levels of these strains were determined, and a strong correlation between cell wall chitin levels and haze protection capability was observed. To further evaluate the mechanism of haze protection, Escherichia coli -produced GFP-tagged grape chitinase was shown to bind efficiently to yeast cell walls in a cell wall chitin concentration-dependent manner, while commercial chitinase was removed from synthetic wine in quantities also correlated with the cell wall chitin levels of the strains. Our findings suggest a new mechanism of reducing wine haze, and propose a strategy for optimizing wine yeast strains to improve wine clarification. Importance In this study, we establish a new mechanism by which wine yeast strains can impact on the protein haze formation of wines, and demonstrate that yeast cell wall chitin binds grape chitinase in a chitin-concentration dependent manner. We also show that yeast can remove this haze-forming protein from wine. Chitin has in the past been shown to efficiently reduce wine haze formation when added to the wine in high concentration as a clarifying agent. Our data suggest that the selection of yeast strains with high levels of cell wall chitin can reduce protein haze. We also

EFEITO DO USO DE AUTOLIZADO DE CERVEJA NO GANHO DE PESO DE BEZERROS DA RAÇA GIR INFLUENCE OF UTILIZED BEER YEAST IN WEIGHT INCREASE OF GIR CALVES

Directory of Open Access Journals (Sweden)

Roulien Fontes

2007-09-01

Full Text Available

O presente trabalho trata do estudo da influência da ingestão do autolizado de fermento de cerveja no ganho de peso de bezerros da Raça Gir. O autolizado de fermento de cerveja é um sub-produto da fabricação de cerveja e apresenta-se rico em aminoácidos, vitaminas e minerais. No experimento foram utilizados 32 bezerros da Raça Gir, machos e fêmeas, distribuídos em blocos casualizados que receberam quatro níveis do dosagens diárias (0; 1; 2 e 3 kg do produto. Após 196 dias de experimento concluiu-se que existe relação significativa entre o ganho de peso e a suplementação com o autolizado e que a dosagem/dia mais adequada é de 1 kg.

The purpose of this paper is to study the influence of autolyzed beer yeast in the increase weight of Gir calves. The autolyzed beer yeast is a by-product of beer brewing. It is rich ix aminoacids, vitamins and minerals. In the experiment there were 32 Gir calves, male and female, divided into aleatory groups, receiving 4 different revels of daily portions (0; 1; 2 and 3kg of the beer yeast. After 196 days of testing, a significant relationship between the increase of weight and the use of autolyzed beer yeast was observed. The amimals must recieve 1 kg of beer yeast daily.

The genetic manipulation of the yeast Saccharomyces cerevisiae with the aim of converting polysaccharide-rich agricultural crops and industrial waste to single-cell protein and fuel ethanol

Directory of Open Access Journals (Sweden)

I. S. Pretorius

1994-07-01

Full Text Available The world’s problem with overpopulation and environmental pollution has created an urgent demand for alternative protein and energy sources. One way of addressing these burning issues is to produce single-cell protein (for food and animal feed supplements and fuel ethanol from polysaccharide-rich agricultural crops and industrial waste by using baker’s yeast.

Brouwen, branden en bedienen. Werkende vrouwen in de Nederlandse dranknijverheid, 1500-1800

NARCIS (Netherlands)

van Dekken, M.

2009-01-01

Brewing was always one of the household activities women performed. Some of them brewed more than needed for their own family and sold the surplus to others. During the Middle Ages commercial brewing in Dutch towns evolved and in a short period brewing industry became to be dominated by men.

The influence of sucrose and maltose on Saccharomyces cerevisiae yeast multiplication

Directory of Open Access Journals (Sweden)

O. I. Ponomareva

2016-01-01

Full Text Available The data on the influence of fermentable carbohydrates concentration on yeast multiplication are widely represented in the literature. This study presents the results of experiments showing an influence of sucrose and maltose concentration on Saccharomyces cerevisiae yeast multiplication. The objects of this research are bakery, beer, wine and alcohol yeast that are widely used in fermentation industry. Beet molasses and malt wort were chosen as nutrient medium for yeast breeding. Their basic sugars are mainly represented by sucrose and maltose. The concentration of sugars was 9, 12, 16 and 20%. The intensity of yeast multiplication was evaluated based on yeast cells concentration during their cultivation and the specific growth rate. Sugar concentrations causing an intensive accumulation of examined yeast strains were determined. This paper presents the experimental data that were received describing the influence of sucrose and maltose concentration on the duration of a lag phase period for different yeast strains. Specific growth rates of researched strains were determined for nutrient mediums with different glucose and maltose concentrations. It was found that the Crabtree effect, that is caused by high carbohydrates concentration in culture medium, is most pronounced when yeast cells grow on a sucrose medium. Brewer’s and baker's yeast are more adapted to high concentrations of carbohydrates. The obtained experimental data could be utilized to develop flow charts of growing a pure culture of Saccharomyces cerevisiae yeast to use at fermentation plants, including low power ones.

Produção de biossurfactante por levedura Biosurfactants production by yeasts

Directory of Open Access Journals (Sweden)

Gizele Cardoso Fontes

2008-01-01

Full Text Available Biosurfactants are molecules extracellularly produced by bacteria, yeast and fungi that have significant interfacial activity properties. This review focuses on relevant parameters that influence biosurfactant production by yeasts. Many works have investigated the optimization of yeast biosurfactant production, mainly within the last decade, revealing that the potential of such microorganisms is not well explored in the industrial field. The main points to increase the process viability lays on the reduction of the production costs and enhancement of biosynthesis efficiency through optimization the culture conditions (carbon and nitrogen source, pH, aeration, speed agitation and the selection of inexpensive medium components.

Engineering yeast metabolism for production of fuels and chemicals

DEFF Research Database (Denmark)

Nielsen, Jens

2016-01-01

faster development of metabolically engineered strains that can be used for production of fuels and chemicals. The yeast Saccharomyces cerevisiae is widely used for production of fuels, chemicals, pharmaceuticals and materials. Through metabolic engineering of this yeast a number of novel industrial...... as for metabolic design. In this lecture it will be demonstrated how the Design-Build-Test cycle of metabolic engineering has allowed for development of yeast cell factories for production of a range of different fuels and chemicals. Some examples of different technologies will be presented together with examples......Metabolic engineering relies on the Design-Build-Test cycle. This cycle includes technologies like mathematical modeling of metabolism, genome editing and advanced tools for phenotypic characterization. In recent years there have been advances in several of these technologies, which has enabled...

Levels of Antioxidant Activity and Fluoride Content in Coffee Infusions of Arabica, Robusta and Green Coffee Beans in According to their Brewing Methods.

Science.gov (United States)

Wolska, J; Janda, Katarzyna; Jakubczyk, K; Szymkowiak, M; Chlubek, D; Gutowska, I

2017-10-01

Coffee is a rich source of dietary antioxidants, and this property links with the fact that coffee is one of the world's most popular beverages. Moreover, it is a source of macro- and microelements, including fluoride. The aim of this work was to determine antioxidant activity of coffee beverages and fluoride content depending on different coffee species and conditions of brewing. Three species of coffee, arabica, robusta and green coffee beans obtained from retail stores in Szczecin (Poland) were analyzed. Five different techniques of preparing drink were used: simple infusion, french press, espresso maker, overflow espresso and Turkish coffee. Antioxidant potential of coffee beverages was investigated spectrophotometrically by DPPH method. Fluoride concentrations were measured by potentiometric method with a fluoride ion-selective electrode. Statistical analysis was performed using Stat Soft Statistica 12.5. Antioxidant activity of infusions was high (71.97-83.21% inhibition of DPPH) depending on coffee species and beverage preparing method. It has been shown that the method of brewing arabica coffee and green coffee significantly affects the antioxidant potential of infusions. The fluoride concentration in the coffee infusions changed depending, both, on the species and conditions of brewing, too (0.013-0.502 mg/L). Methods of brewing didn't make a difference to the antioxidant potential of robusta coffee, which had also the lowest level of fluoride among studied species. Except overflow espresso, the fluoride content was the highest in beverages from green coffee. The highest fluoride content was found in Turkish coffee from green coffee beans.

Tapping into yeast diversity.

Science.gov (United States)

Fay, Justin C

2012-11-01

Domesticated organisms demonstrate our capacity to influence wild species but also provide us with the opportunity to understand rapid evolution in the context of substantially altered environments and novel selective pressures. Recent advances in genetics and genomics have brought unprecedented insights into the domestication of many organisms and have opened new avenues for further improvements to be made. Yet, our ability to engineer biological systems is not without limits; genetic manipulation is often quite difficult. The budding yeast, Saccharomyces cerevisiae, is not only one of the most powerful model organisms, but is also the premier producer of fermented foods and beverages around the globe. As a model system, it entertains a hefty workforce dedicated to deciphering its genome and the function it encodes at a rich mechanistic level. As a producer, it is used to make leavened bread, and dozens of different alcoholic beverages, such as beer and wine. Yet, applying the awesome power of yeast genetics to understanding its origins and evolution requires some knowledge of its wild ancestors and the environments from which they were derived. A number of surprisingly diverse lineages of S. cerevisiae from both primeval and secondary forests in China have been discovered by Wang and his colleagues. These lineages substantially expand our knowledge of wild yeast diversity and will be a boon to elucidating the ecology, evolution and domestication of this academic and industrial workhorse.

Porovnání tradiční výroby piva s moderními technologiemi

OpenAIRE

FLOSOVÁ, Anna

2011-01-01

Presented Bachelor thesis was focused on comparison of traditional beer production with modern technologies. From comprehensive theory of beer brewing technology was the main point of the work devoted to brewer´s yeast and beer fermentation process, which has made the greatest progress during the development of beer production technology. Chapter about brewer´s yeast is dealing with their taxonomy, morfology and cytology, structure, reproduction and types of yeast, bottom and top fermenting y...

Mass spectrometry for the characterization of brewing process.

Science.gov (United States)

Vivian, Adriana Fu; Aoyagui, Caroline Tiemi; de Oliveira, Diogo Noin; Catharino, Rodrigo Ramos

2016-11-01

Beer is a carbonated alcoholic beverage produced by fermenting ingredients containing starch, especially malted cereals, and other compounds such as water, hops and yeast. The process comprises five main steps: malting, mashing, boiling, fermentation and maturation. There has been growing interest in the subject, since there is increasing demand for beer quality aspects and beer is a ubiquitous alcoholic beverage in the world. This study is based on the manufacturing process of a Brazilian craft brewery, which is characterized by withdrawing samples during key production stages and using electrospray ionization (ESI) high-resolution mass spectrometry (HRMS), a selective and reliable technique used in the identification of substances in an expeditious and practical way. Multivariate data analysis, namely partial least squares discriminant analysis (PLS-DA) is used to define its markers. In both positive and negative modes of PLS-DA score plot, it is possible to notice differences between each stage. VIP score analysis pointed out markers coherent with the process, such as barley components ((+)-catechin), small peptide varieties, hop content (humulone), yeast metabolic compounds and, in maturation, flavoring compounds (caproic acid, glutaric acid and 2,3-butanediol). Besides that, it was possible to identify other important substances such as off-flavor precursors and other different trace compounds, according to the focus given. This is an attractive alternative for the control of food and beverage industry, allowing a quick assessment of process status before it is finished, preventing higher production costs, ensuring quality and helping the control of desirable features, as flavor, foam stability and drinkability. Covering different classes of compounds, this approach suggests a novel analytical strategy: "processomics", aiming at understanding processes in detail, promoting control and being able to make improvements. Copyright © 2016 Elsevier Ltd. All rights

PREPARATION OF ZINC ENRICHED YEAST (SACCHAROMYCES CEREVISIAE BY CULTIVATION WITH DIFFERENT ZINC SALTS

Directory of Open Access Journals (Sweden)

Ľuboš Harangozo

2012-02-01

Full Text Available The yeast Saccharomyces cerevisiae is the best known microorganism and therefore widely used in many branches of industry. This study aims to investigate the accumulation of three inorganic zinc salts. Our research presents the ability of this yeast to absorb zinc from liquid medium and such enriched biomass use as a potential source of microelements in animal and/or human nutrition. It was found that the addition of different zinc forms, i.e. zinc nitrate, zinc sulphate and zinc chloride in fixed concentrations of 0, 25, 50 and 100 mg.100 ml-1 did not affect the amount of dry yeast biomass yielded, i.e. 1.0 – 1.2 g of yeast cells from 100 ml of cultivation medium, while higher presence of zinc solutions caused significantly lower yield of yeast biomass. The highest amount of zinc in yeast cells was achieved when added in the form of zinc nitrate in concentration of 200 mg.100 ml-1 YPD medium. The increment of intracellular zinc was up to 18.5 mg.g-1 of yeast biomass.

Effect of different brewing times on antioxidant activity and polyphenol content of loosely packed and bagged black teas (Camellia sinensis L.).

Science.gov (United States)

Nikniaz, Zeinab; Mahdavi, Reza; Ghaemmaghami, Seyed Jamal; Lotfi Yagin, Neda; Nikniaz, Leila

2016-01-01

Determination and comparison of the effect of infusion time on the antioxidant activity and total polyphenol contents of bagged and loosely packed black teas. For twenty loosely packed and eleven bagged tea samples, the antioxidant activity and total polyphenol content were analyzed using FRAP and Folin-Ciocalteau methods, respectively. The ANOVA with Tukey post-hoc test and independent t-test were used for statistical analysis. The antioxidant activity and polyphenol content of various brands of tea samples were significantly different. There were significant differences in the antioxidant activity of loosely packed teas between 5, 15(p=0.03), 30(p=0.02) and 60(p=0.007) minutes of brewing times. Besides, there was a significant difference in antioxidant activity of bagged samples infused for 1 minute with four other infusion time points (pbrewing times (p=0.15). However, in bagged samples, the polyphenol contents of samples that were brewed for 1 minute were significantly lower than samples brewed for 3, 4, and 5 minutes (pbrewing time (p<0.001). The infusion time and the form of tea (loosely packed or bagged) were shown to be important determinants of the antioxidant activity and polyphenol content of black tea infusions in addition to the variety, growing environment and manufacturing conditions.

Microfluidic screening and whole-genome sequencing identifies mutations associated with improved protein secretion by yeast

DEFF Research Database (Denmark)

Huang, Mingtao; Bai, Yunpeng; Sjostrom, Staffan L.

2015-01-01

There is an increasing demand for biotech-based production of recombinant proteins for use as pharmaceuticals in the food and feed industry and in industrial applications. Yeast Saccharomyces cerevisiae is among preferred cell factories for recombinant protein production, and there is increasing...... interest in improving its protein secretion capacity. Due to the complexity of the secretory machinery in eukaryotic cells, it is difficult to apply rational engineering for construction of improved strains. Here we used high-throughput microfluidics for the screening of yeast libraries, generated by UV...... mutagenesis. Several screening and sorting rounds resulted in the selection of eight yeast clones with significantly improved secretion of recombinant a-amylase. Efficient secretion was genetically stable in the selected clones. We performed whole-genome sequencing of the eight clones and identified 330...

Whole-Genome Analysis of Three Yeast Strains Used for Production of Sherry-Like Wines Revealed Genetic Traits Specific to Flor Yeasts

Science.gov (United States)

Eldarov, Mikhail A.; Beletsky, Alexey V.; Tanashchuk, Tatiana N.; Kishkovskaya, Svetlana A.; Ravin, Nikolai V.; Mardanov, Andrey V.

2018-01-01

Flor yeast strains represent a specialized group of Saccharomyces cerevisiae yeasts used for biological wine aging. We have sequenced the genomes of three flor strains originated from different geographic regions and used for production of sherry-like wines in Russia. According to the obtained phylogeny of 118 yeast strains, flor strains form very tight cluster adjacent to the main wine clade. SNP analysis versus available genomes of wine and flor strains revealed 2,270 genetic variants in 1,337 loci specific to flor strains. Gene ontology analysis in combination with gene content evaluation revealed a complex landscape of possibly adaptive genetic changes in flor yeast, related to genes associated with cell morphology, mitotic cell cycle, ion homeostasis, DNA repair, carbohydrate metabolism, lipid metabolism, and cell wall biogenesis. Pangenomic analysis discovered the presence of several well-known “non-reference” loci of potential industrial importance. Events of gene loss included deletions of asparaginase genes, maltose utilization locus, and FRE-FIT locus involved in iron transport. The latter in combination with a flor-yeast-specific mutation in the Aft1 transcription factor gene is likely to be responsible for the discovered phenotype of increased iron sensitivity and improved iron uptake of analyzed strains. Expansion of the coding region of the FLO11 flocullin gene and alteration of the balance between members of the FLO gene family are likely to positively affect the well-known propensity of flor strains for velum formation. Our study provides new insights in the nature of genetic variation in flor yeast strains and demonstrates that different adaptive properties of flor yeast strains could have evolved through different mechanisms of genetic variation. PMID:29867869

Development of a PCR assay based on the 16S-23S rDNA internal transcribed spacer for identification of strictly anaerobic bacterium Zymophilus

Czech Academy of Sciences Publication Activity Database

Felsberg, Jürgen; Jelínková, Markéta; Kubizniaková, P.; Matoulková, D.

2015-01-01

Roč. 33, June (2015), s. 85-89 ISSN 1075-9964 Institutional support: RVO:61388971 Keywords : Brewing microbiology * Strictly anaerobic bacteria * Yeast contamination Subject RIV: GM - Food Processing Impact factor: 2.424, year: 2015

How grinding level and brewing method (Espresso, American, Turkish) could affect the antioxidant activity and bioactive compounds in a coffee cup.

Science.gov (United States)

Derossi, Antonio; Ricci, Ilde; Caporizzi, Rossella; Fiore, Anna; Severini, Carla

2018-06-01

Depending on geographical origin and cultural traditions, different brewing procedures are used all over the world to prepare a cup of coffee. In this work, we explored how three grinding levels of coffee powder and three coffee preparation methods - filtration (American), boiling (Turkish) and extraction under pressure (Espresso) - affect healthy compounds and physicochemical attributes in coffee served to consumers. Grinding level slightly affected the quality of coffee, whereas the preparation method significantly influenced all in-cup attributes. When the content per cup was compared, the American coffee presented higher values of antioxidant activity and total phenol content than espresso and Turkish coffees. Caffeine content was 316, 112 and 64 mg for the American, Turkish and espresso coffee cup, respectively. One American, three Turkish and five Espresso coffee cups contain similar amount of caffeine of 316, 336 and 320 mg, respectively which are below the maximum daily consumption (400 mg per day) suggested by the European Food Safety Authority. The extraction method affects the intake of bioactive and antioxidant substances with specific properties. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Stereoselective Behavior of the Chiral Herbicides Diclofop-Methyl and Diclofop During the Soy Sauce Brewing Process.

Science.gov (United States)

Lu, Yuele; Zhang, Dong; Liao, Yahui; Diao, Jinling; Chen, Xiaolong

2016-01-01

Chiral pesticides are now receiving more and more attention in the food-making process. This experiment studied the enantioselective behavior of diclofop-methyl (DM) and its main metabolite, diclofop (DC), during the soy sauce brewing process. Two kinds of commonly used strains, Aspergillus oryzae and Saccharomyces rouxii, were investigated. However, they showed a different degradation ability to the enantiomers of DM and DC. It was observed that (-)-(S)-DM was degraded much faster than (+)-(R)-DM by Saccharomyces rouxii, while no stereoselective degradation was found by Aspergillus oryzae. DC represented a relatively long residue period in this fermentation process and both strains showed a weak degradation ability to DC, especially Saccharomyces rouxii. There was little DC detected in the final product, while most of the DC residues persisted in the lees, which were usually used as animal feeds or discarded into the environment directly as waste. Therefore, more attention should be paid to the soy sauce brewing process concerning pesticide residues both in the final product and byproducts. © 2015 Wiley Periodicals, Inc.

Bioprocess Intensification of Beer Fermentation Using Immobilised Cells

Science.gov (United States)

Verbelen, Pieter J.; Nedović, Viktor A.; Manojlović, Verica; Delvaux, Freddy R.; Laskošek-Čukalović, Ida; Bugarski, Branko; Willaert, Ronnie

Beer production with immobilised yeast has been the subject of research for approximately 30 years but has so far found limited application in the brewing industry, due to engineering problems, unrealised cost advantages, microbial contaminations and an unbalanced beer flavor (Linko et al. 1998; Brányik et al. 2005; Willaert and Nedović 2006). The ultimate aim of this research is the production of beer of desired quality within 1-3 days. Traditional beer fermentation systems use freely suspended yeast cells to ferment wort in an unstirred batch reactor. The primary fermentation takes approximately 7 days with a subsequent secondary fermentation (maturation) of several weeks. A batch culture system employing immobilization could benefit from an increased rate of fermentation. However, it appears that in terms of increasing productivity, a continuous fermentation system with immobilization would be the best method (Verbelen et al. 2006). An important issue of the research area is whether beer can be produced by immobilised yeast in continuous culture with the same characteristic as the traditional method.

Uranium uptake by baker's yeast (Saccharomyces cerevisiae) - development of a biological ion exchanger

International Nuclear Information System (INIS)

Oost, T.; Schoening, K.U.

1991-01-01

The use of micro-organisms for decontamination of, and heavy metal recovery from industrial waste water is a modern, low-cost, and environmentally friendly alternative to the conventional chemical and physical methods. The uptake of uranium by baker's yeast is investigated under the aspect of application in biotechnology. A novel, regenerable biological ion exchanger was produced by immobilisation of the yeast in agar gel. (orig.) [de

In situ rheology of yeast biofilms.

Science.gov (United States)

Brugnoni, Lorena I; Tarifa, María C; Lozano, Jorge E; Genovese, Diego

2014-01-01

The aim of the present work was to investigate the in situ rheological behavior of yeast biofilms growing on stainless steel under static and turbulent flow. The species used (Rhodototula mucilaginosa, Candida krusei, Candida kefyr and Candida tropicalis) were isolated from a clarified apple juice industry. The flow conditions impacted biofilm composition over time, with a predominance of C. krusei under static and turbulent flow. Likewise, structural variations occurred, with a tighter appearance under dynamic flow. Under turbulent flow there was an increase of 112 μm in biofilm thickness at 11 weeks (p < 0.001) and cell morphology was governed by hyphal structures and rounded cells. Using the in situ growth method introduced here, yeast biofilms were determined to be viscoelastic materials with a predominantly solid-like behavior, and neither this nor the G'0 values were significantly affected by the flow conditions or the growth time, and at large deformations their weak structure collapsed beyond a critical strain of about 1.5-5%. The present work could represent a starting point for developing in situ measurements of yeast rheology and contribute to a thin body of knowledge about fungal biofilm formation.

Yarrowia lipolytica: a model yeast for citric acid production.

Science.gov (United States)

Cavallo, Ema; Charreau, Hernán; Cerrutti, Patricia; Foresti, María Laura

2017-12-01

Every year more than 2 million tons of citric acid (CA) are produced around the world for industrial uses. Although initially extracted from citrus, the low profitability of the process and the increasing demand soon stimulated the search for more efficient methods to produce CA. Currently, most world CA demand (99%) is satisfied by fermentations with microorganisms, especially filamentous fungi and yeasts. CA production with yeasts has certain advantages over molds (e.g. higher productivity and easier cultivation), which in the last two decades have triggered a clear increase in publications and patents devoted to the use of yeasts in this field. Yarrowia lipolytica has become a model yeast that proved to be successful in different production systems. Considering the current interest evidenced in the literature, the most significant information on CA production using Y. lipolytica is summarized. The relevance on CA yields of key factors such as strains, media formulation, environmental conditions and production regimes is thoroughly discussed, with particular focus on increasing CA productivity. Besides, the possibility of tuning the mentioned variables to reduce concomitant isocitric acid production-the biggest disadvantage of using yeasts-is analyzed. Available methods for CA purification/quantification are also discussed. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Synthetic biology for engineering acetyl coenzyme a metabolism in yeast

DEFF Research Database (Denmark)

Nielsen, Jens

2014-01-01

The yeast Saccharomyces cerevisiae is a widely used cell factory for the production of fuels, chemicals, and pharmaceuticals. The use of this cell factory for cost-efficient production of novel fuels and chemicals requires high yields and low by-product production. Many industrially interesting...... chemicals are biosynthesized from acetyl coenzyme A (acetyl-CoA), which serves as a central precursor metabolite in yeast. To ensure high yields in production of these chemicals, it is necessary to engineer the central carbon metabolism so that ethanol production is minimized (or eliminated) and acetyl...

THE DEPENDENCE OF GLYCEROL ACCUMULATION AND STARCH HYDROLYZATES FERMENTATION FROM WORT CONCENTRATION

Directory of Open Access Journals (Sweden)

Оliynichuk S. Т.

2015-08-01

Full Text Available The purpose of this work is to study the dependence of ethanol accumulation by-products and secondary products (glycerol and propionic acid during the fermentation in the case of increasing the wort concentration from 12 to 21% by weight of sugar as an example of commonly used in the alcohol industry the commercial dry yeast company “Danisco” and experimental osmophilic strain Saccharomyces cerevisiae DS-02-E, isolated from a concentrated (80% DM of rye malt wort which spontaneously fermented. The enzyme preparations “AMYLEX 4T”, “ALPHALASE AFP” and “DIAZYME SSF” were used for the liquefaction and saccharification of starch wort. The finished industrial of both yeast strains were added to the fermentation flasks in an amount of 10% by volume of the primary wort. In the mature brew the unfermented carbohydrates content was determined by colorimetric method with anthrone reagent, alcohol — by glass areometer-alcoholometer, acidity — potentiometrically, the concentration of dry matter — by areometer, glycerol content — by photocolorimetry method. In the brew distillate a volatile impurities content, namely propionic acid, was determined using gas chromatography. Statistical processing of the results of three series of experiments were carried out by calculating the arithmetical mean value of 5 measurements, their standard deviations and errors. To determine the probable differences between the mean values were used Student’s t test. Differences were considered statistically significant at P < 0.05. Reduction for accumulation of glycerol (between 38 till 53% at higher concentrations of nutrient medium in the case of the yeast Saccharomyces cerevisiae DS-02-E as compared with commercial dry yeast, reduction the formation of unwanted by-product of fermentation — propionic acid (up to 34%, a better ability of the experimental strain to accumulate sugar of wort and to accumulate ethanol (up to 0.1–0.25% vol. were shown. It

Ethanol production potential of local yeast strains isolated from ripe ...

African Journals Online (AJOL)

STORAGESEVER

2008-05-16

May 16, 2008 ... ... of these studies, the preferred candidate for industrial production of ethanol ... The yeast strains were isolated using the method of Ameh et al. (1989), on ... gas in the Durham tube during the incubation period. Fermentation ...

Removal of heavy metals from metal-containing effluent by yeast ...

African Journals Online (AJOL)

Removal of heavy metals from metal-containing effluent by yeast biomass. ... Research studies have described this phenomenon of fast initial sorption with a ... chrome and tin from the chrome and tin effluents of a local iron and steel industry.

Environmental influences on organotin-yeast interactions

OpenAIRE

White, Jane S.

2002-01-01

As a consequence of the widespread industrial and agricultural applications of organotin compounds, contamination of various ecosystems has occurred in recent decades. Understanding how these compounds interact with cellular membranes is essential in assessing the risks of organotin pollution. The organotins, tributyltin (TBT) and trimethyltin (TMT) and inorganic tin, Sn(IV), were investigated for their physical interactions with non-metabolising cells and protoplasts of the yeast, Candida ma...

Porn video shows, local brew, and transactional sex: HIV risk among youth in Kisumu, Kenya.

Science.gov (United States)

Njue, Carolyne; Voeten, Helene A C M; Remes, Pieter

2011-08-08

Kisumu has shown a rising HIV prevalence over the past sentinel surveillance surveys, and most new infections are occurring among youth. We conducted a qualitative study to explore risk situations that can explain the high HIV prevalence among youth in Kisumu town, Kenya We conducted in-depth interviews with 150 adolescents aged 15 to 20, held 4 focus group discussions, and made 48 observations at places where youth spend their free time. Porn video shows and local brew dens were identified as popular events where unprotected multipartner, concurrent, coerced and transactional sex occurs between adolescents. Video halls - rooms with a TV and VCR - often show pornography at night for a very small fee, and minors are allowed. Forced sex, gang rape and multiple concurrent relationships characterised the sexual encounters of youth, frequently facilitated by the abuse of alcohol, which is available for minors at low cost in local brew dens. For many sexually active girls, their vulnerability to STI/HIV infection is enhanced due to financial inequality, gender-related power difference and cultural norms. The desire for love and sexual pleasure also contributed to their multiple concurrent partnerships. A substantial number of girls and young women engaged in transactional sex, often with much older working partners. These partners had a stronger socio-economic position than young women, enabling them to use money/gifts as leverage for sex. Condom use was irregular during all types of sexual encounters. In Kisumu, local brew dens and porn video halls facilitate risky sexual encounters between youth. These places should be regulated and monitored by the government. Our study strongly points to female vulnerabilities and the role of men in perpetuating the local epidemic. Young men should be targeted in prevention activities, to change their attitudes related to power and control in relationships. Girls should be empowered how to negotiate safe sex, and their poverty should

Porn video shows, local brew, and transactional sex: HIV risk among youth in Kisumu, Kenya

Directory of Open Access Journals (Sweden)

Voeten Helene ACM

2011-08-01

Full Text Available Abstract Background Kisumu has shown a rising HIV prevalence over the past sentinel surveillance surveys, and most new infections are occurring among youth. We conducted a qualitative study to explore risk situations that can explain the high HIV prevalence among youth in Kisumu town, Kenya Methods We conducted in-depth interviews with 150 adolescents aged 15 to 20, held 4 focus group discussions, and made 48 observations at places where youth spend their free time. Results Porn video shows and local brew dens were identified as popular events where unprotected multipartner, concurrent, coerced and transactional sex occurs between adolescents. Video halls - rooms with a TV and VCR - often show pornography at night for a very small fee, and minors are allowed. Forced sex, gang rape and multiple concurrent relationships characterised the sexual encounters of youth, frequently facilitated by the abuse of alcohol, which is available for minors at low cost in local brew dens. For many sexually active girls, their vulnerability to STI/HIV infection is enhanced due to financial inequality, gender-related power difference and cultural norms. The desire for love and sexual pleasure also contributed to their multiple concurrent partnerships. A substantial number of girls and young women engaged in transactional sex, often with much older working partners. These partners had a stronger socio-economic position than young women, enabling them to use money/gifts as leverage for sex. Condom use was irregular during all types of sexual encounters. Conclusions In Kisumu, local brew dens and porn video halls facilitate risky sexual encounters between youth. These places should be regulated and monitored by the government. Our study strongly points to female vulnerabilities and the role of men in perpetuating the local epidemic. Young men should be targeted in prevention activities, to change their attitudes related to power and control in relationships. Girls

Prions in yeast

OpenAIRE

Bezdíčka, Martin

2013-01-01

The thesis describes yeast prions and their biological effects on yeast in general. It defines the basic characteristics of yeast prions, that distinguish prions from other proteins. The thesis introduces various possibilities of prion formation, and propagation as well as specific types of yeast prions, including various functions of most studied types of prions. The thesis also focuses on chaperones that affect the state of yeast prions in cells. Lastly, the thesis indicates similarities be...

Isolation and Characterization of melanized yeast form of Aureobasidium pullulans and physiological studies on the melanization process

International Nuclear Information System (INIS)

El-Gamal, M.S.; El-Bialy, H.A.; Elsayed, M.A.; Khalifa, M.A.

2017-01-01

Melanin pigments have immense application potentials in the fields of agriculture , cosmetics and pharmaceutical industries . Isolation and characterization of melanin producer from local resources is the main aim of the present study . Six melanized yeast isolates were selected from seventeen isolation resources including natural sources (Eucalyptus globules plant), industrial wastes (Tomato paste processing) and surface contaminants (Bathrooms). The selected yeasts were screened for melanin production in an individual experiment , results revealed the ability of yeast isolate selected from wastes of tomato paste processing (W 3 ) to produce melanin at 300 mM concentration . The selected melanized yeast was identified as Aureobasidium pullulans according to the morphological characteristics and 18S rRNA . Melanin production by the selected yeast was maximized by optimization of the cultural conditions and nutritional parameters by nearly two folds ( 550 mM ). The highest melanin yield was achieved in the fermentation medium contains 30 gl -1 sucrose , 35 gl -1 peptone and 1 mM L - DOPA concentration after nine days of incubation at 30°C and its pH value is adjusted at 7.0. Melanin characterization by FTIR and NMR resemble aliphatic and aromatic composition of A . pullulans ’ s melanin . In conclusion, the selected yeast is a promising candidate for melanin production in a semipilot scale

Designing and creating Saccharomyces interspecific hybrids for improved, industry relevant, phenotypes.

Science.gov (United States)

Bellon, Jennifer R; Yang, Fei; Day, Martin P; Inglis, Debra L; Chambers, Paul J

2015-10-01

To remain competitive in increasingly overcrowded markets, yeast strain development programmes are crucial for fermentation-based food and beverage industries. In a winemaking context, there are many yeast phenotypes that stand to be improved. For example, winemakers endeavouring to produce sweet dessert wines wrestle with fermentation challenges particular to fermenting high-sugar juices, which can lead to elevated volatile acidity levels and extended fermentation times. In the current study, we used natural yeast breeding techniques to generate Saccharomyces spp. interspecific hybrids as a non-genetically modified (GM) strategy to introduce targeted improvements in important, wine-relevant traits. The hybrids were generated by mating a robust wine strain of Saccharomyces cerevisiae with a wine isolate of Saccharomyces bayanus, a species previously reported to produce wines with low concentrations of acetic acid. Two hybrids generated from the cross showed robust fermentation properties in high-sugar grape juice and produced botrytised Riesling wines with much lower concentrations of acetic acid relative to the industrial wine yeast parent. The hybrids also displayed suitability for icewine production when bench-marked against an industry standard icewine yeast, by delivering icewines with lower levels of acetic acid. Additionally, the hybrid yeast produced wines with novel aroma and flavour profiles and established that choice of yeast strain impacts on wine colour. These new hybrid yeasts display the desired targeted fermentation phenotypes from both parents, robust fermentation in high-sugar juice and the production of wines with low volatile acidity, thus establishing their suitability for wine styles that are traditionally troubled by excessive volatile acidity levels.

Hyphal-like extension and pseudohyphal formation in industrial strains of yeasts induced by isoamyl alcohol

OpenAIRE

Ceccato-Antonini, Sandra Regina; Silva, Paula Cristina da

2002-01-01

Yeasts can produce pseudohyphae and hyphal-like extensions under certain growth conditions like isoamyl alcohol (IAA) induction, a chief constituent of fusel oil, which is a subproduct from the ethanolic fermentation. The morphology switch from yeast to a filamentous form can be troublesome to the process. In this work it was studied the influence of fusel alcohols, nitrogen sources (ammonium sulphate and leucine) and glifosate (a chemical maturator for sugar cane) added to a complex medium o...

An original method for producing acetaldehyde and diacetyl by yeast fermentation

Directory of Open Access Journals (Sweden)

Irina Rosca

Full Text Available Abstract In this study a natural culture medium that mimics the synthetic yeast peptone glucose medium used for yeast fermentations was designed to screen and select yeasts capable of producing high levels of diacetyl and acetaldehyde. The presence of whey powder and sodium citrate in the medium along with manganese and magnesium sulfate enhanced both biomass and aroma development. A total of 52 yeasts strains were cultivated in two different culture media, namely, yeast peptone glucose medium and yeast acetaldehyde-diacetyl medium. The initial screening of the strains was based on the qualitative reaction of the acetaldehyde with Schiff's reagent (violet color and diacetyl with Brady's reagent (yellow precipitate. The fermented culture media of 10 yeast strains were subsequently analyzed by gas chromatography to quantify the concentration of acetaldehyde and diacetyl synthesized. Total titratable acidity values indicated that a total titratable acidity of 5.5 °SH, implying culture medium at basic pH, was more favorable for the acetaldehyde biosynthesis using strain D15 (Candida lipolytica; 96.05 mg L-1 acetaldehyde while a total titratable acidity value of 7 °SH facilitated diacetyl flavor synthesis by strain D38 (Candida globosa; 3.58 mg L-1 diacetyl. Importantly, the results presented here suggest that this can be potentially used in the baking industry.

Metals uptake by live yeast and heat-modified yeast residue

Directory of Open Access Journals (Sweden)

Geórgia Labuto

2015-07-01

Full Text Available This study evaluated the biosorption of Cd2+, Cr3+, Pb2+ and Cu2+ at pHs 3, 4, 5 and 6 for Saccharomyces cerevisiae both alive and biologically inactivated by different heating procedures (oven, autoclave or spray dry technique originated from alcohol industry. The material inactivated by autoclave (IA, at 120°C, 30 min had the best performance for metals uptake: 1.88 ± 0.07 (Cu2+, 2.22 ± 0.02 (Cr3+ and 1.57 ± 0.08 g kg-1 (Pb2+. For Cd2+; while the material inactivated by spray dry (RY presented the higher sorption capacity, 2.30 ± 0.08 g kg-1. The sorption studies showed that the biosorbent materials presented different sorption capacities and an ideal sorption pH. The sorption sites were investigated by potentiometric titration and FT-IR and showed that different heating processes used to inactivate biological samples produce materials with different characteristics and with a diverse sorption capacity due to modification of the available sorption sites. This suggests that inactivation by heating can be an alternative to improve the performance of biosorbents. The main sorption sites for each material were phenolic for live yeast (LY and carboxylic for yeast inactivated by heating in an autoclave (IA.

Simultaneous saccharification and fermentation of Agave tequilana fructans by Kluyveromyces marxianus yeasts for bioethanol and tequila production.

Science.gov (United States)

Flores, Jose-Axel; Gschaedler, Anne; Amaya-Delgado, Lorena; Herrera-López, Enrique J; Arellano, Melchor; Arrizon, Javier

2013-10-01

Agave tequilana fructans (ATF) constitute a substrate for bioethanol and tequila industries. As Kluyveromyces marxianus produces specific fructanases for ATF hydrolysis, as well as ethanol, it can perform simultaneous saccharification and fermentation. In this work, fifteen K. marxianus yeasts were evaluated to develop inoculums with fructanase activity on ATF. These inoculums were added to an ATF medium for simultaneous saccharification and fermentation. All the yeasts, showed exo-fructanhydrolase activity with different substrate specificities. The yeast with highest fructanase activity in the inoculums showed the lowest ethanol production level (20 g/l). Five K. marxianus strains were the most suitable for the simultaneous saccharification and fermentation of ATF. The volatile compounds composition was evaluated at the end of fermentation, and a high diversity was observed between yeasts, nevertheless all of them produced high levels of isobutyl alcohol. The simultaneous saccharification and fermentation of ATF with K. marxianus strains has potential for industrial application. Copyright © 2013 Elsevier Ltd. All rights reserved.

High coffee consumption and different brewing methods in relation to postmenopausal endometrial cancer risk in the Norwegian women and cancer study: a population-based prospective study.

Science.gov (United States)

Gavrilyuk, Oxana; Braaten, Tonje; Skeie, Guri; Weiderpass, Elisabete; Dumeaux, Vanessa; Lund, Eiliv

2014-03-25

Coffee and its compounds have been proposed to inhibit endometrial carcinogenesis. Studies in the Norwegian population can be especially interesting due to the high coffee consumption and increasing incidence of endometrial cancer in the country. A total of 97 926 postmenopausal Norwegian women from the population-based prospective Norwegian Women and Cancer (NOWAC) Study, were included in the present analysis. We evaluated the general association between total coffee consumption and endometrial cancer risk as well as the possible impact of brewing method. Multivariate Cox regression analysis was used to estimate risks, and heterogeneity tests were performed to compare brewing methods. During an average of 10.9 years of follow-up, 462 incident endometrial cancer cases were identified. After multivariate adjustment, significant risk reduction was found among participants who drank ≥8 cups/day of coffee with a hazard ratio of 0.52 (95% confidence interval, CI 0.34-0.79). However, we did not observe a significant dose-response relationship. No significant heterogeneity in risk was found when comparing filtered and boiled coffee brewing methods. A reduction in endometrial cancer risk was observed in subgroup analyses among participants who drank ≥8 cups/day and had a body mass index ≥25 kg/m2, and in current smokers. These data suggest that in this population with high coffee consumption, endometrial cancer risk decreases in women consuming ≥8 cups/day, independent of brewing method.

HAA1 and PRS3 overexpression boosts yeast tolerance towards acetic acid improving xylose or glucose consumption: unravelling the underlying mechanisms.

Science.gov (United States)

Cunha, Joana T; Costa, Carlos E; Ferraz, Luís; Romaní, Aloia; Johansson, Björn; Sá-Correia, Isabel; Domingues, Lucília

2018-04-02

Acetic acid tolerance and xylose consumption are desirable traits for yeast strains used in industrial biotechnological processes. In this work, overexpression of a weak acid stress transcriptional activator encoded by the gene HAA1 and a phosphoribosyl pyrophosphate synthetase encoded by PRS3 in a recombinant industrial Saccharomyces cerevisiae strain containing a xylose metabolic pathway was evaluated in the presence of acetic acid in xylose- or glucose-containing media. HAA1 or PRS3 overexpression resulted in superior yeast growth and higher sugar consumption capacities in the presence of 4 g/L acetic acid, and a positive synergistic effect resulted from the simultaneous overexpression of both genes. Overexpressing these genes also improved yeast adaptation to a non-detoxified hardwood hydrolysate with a high acetic acid content. Furthermore, the overexpression of HAA1 and/or PRS3 was found to increase the robustness of yeast cell wall when challenged with acetic acid stress, suggesting the involvement of the modulation of the cell wall integrity pathway. This study clearly shows HAA1 and/or, for the first time, PRS3 overexpression to play an important role in the improvement of industrial yeast tolerance towards acetic acid. The results expand the molecular toolbox and add to the current understanding of the mechanisms involved in higher acetic acid tolerance, paving the way for the further development of more efficient industrial processes.

Under pressure: evolutionary engineering of yeast strains for improved performance in fuels and chemicals production

NARCIS (Netherlands)

Mans, R.; Daran, J.G.; Pronk, J.T.

2018-01-01

Evolutionary engineering, which uses laboratory evolution to select for industrially relevant traits, is a popular strategy in the development of high-performing yeast strains for industrial production of fuels and chemicals. By integrating whole-genome sequencing, bioinformatics, classical

Genome and metabolic engineering in non-conventional yeasts: Current advances and applications.

Science.gov (United States)

Löbs, Ann-Kathrin; Schwartz, Cory; Wheeldon, Ian

2017-09-01

Microbial production of chemicals and proteins from biomass-derived and waste sugar streams is a rapidly growing area of research and development. While the model yeast Saccharomyces cerevisia e is an excellent host for the conversion of glucose to ethanol, production of other chemicals from alternative substrates often requires extensive strain engineering. To avoid complex and intensive engineering of S. cerevisiae, other yeasts are often selected as hosts for bioprocessing based on their natural capacity to produce a desired product: for example, the efficient production and secretion of proteins, lipids, and primary metabolites that have value as commodity chemicals. Even when using yeasts with beneficial native phenotypes, metabolic engineering to increase yield, titer, and production rate is essential. The non-conventional yeasts Kluyveromyces lactis, K. marxianus, Scheffersomyces stipitis, Yarrowia lipolytica, Hansenula polymorpha and Pichia pastoris have been developed as eukaryotic hosts because of their desirable phenotypes, including thermotolerance, assimilation of diverse carbon sources, and high protein secretion. However, advanced metabolic engineering in these yeasts has been limited. This review outlines the challenges of using non-conventional yeasts for strain and pathway engineering, and discusses the developed solutions to these problems and the resulting applications in industrial biotechnology.

Antibacterial effect of grapefruit seed extract (GSE) on Makgeolli-brewing microorganisms and its application in the preservation of fresh Makgeolli.

Science.gov (United States)

Choi, Jae-Suk; Lee, Yu-Ri; Ha, Yu-Mi; Seo, Hyo Ju; Kim, Young Hun; Park, Sun-Mee; Sohn, Jae Hak

2014-06-01

To develop a new preservation method, the antimicrobial activity of grapefruit seed extract (GSE) against Makgeolli-brewing microorganisms and food-borne pathogens was assessed, and a general analysis and sensory evaluation of fresh Makgeolli with added GSE was made. The minimum inhibitory concentration (MIC) values of GSE against 10 strains of Makgeolli-brewing microorganism were 0.0122 to 1.5625 μL/mL. The MIC values against 6 strains of food-borne pathogens were 0.0061 to 0.7813 μL/mL. On addition of 0.1% (v/v) and 0.2% GSE in bottled fresh Makgeolli, no significant difference in the pH, or the contents of total acids, ethanol, or methanol in the Makgeolli, were observed compared with control Makgeolli (with no GSE), during the preservation period (8 weeks) at 10 °C. In the Makgeolli with 0.1% and 0.2% GSE, the total bacterial counts decreased significantly by 4.9% (P grapefruit seed extract (GSE) was developed. As fresh Makgeolli contains live microorganisms, the preservation period is 1 wk, which is relatively short. GSE controls the growth of Makgeolli-brewing and Makgeolli-spoiling microorganisms. 0.1% to 0.2% GSE is optimum for prolonging the shelf life (2 wk) of bottled fresh Makgeolli, and has no adverse effect on overall acceptability. We demonstrated that GSE is an effective natural additive that prolongs the shelf life of fresh Makgeolli with no significant loss in quality. © 2014 Institute of Food Technologists®

Difference of microbial community stressed in artificial pit muds for Luzhou-flavour liquor brewing revealed by multiphase culture-independent technology.

Science.gov (United States)

Zhang, L; Zhou, R; Niu, M; Zheng, J; Wu, C

2015-11-01

Artificial pit muds (APMs) is produced by peats, aged pit muds, yellow and black clays etc. and is one of essential factors for Luzhou-flavour liquor production. The microbial community of APMs significantly influence the quality of Luzhou-flavour liquor. The aim of this study was to investigate the differences in bacterial, archaeal and fungal community of APMs, starters and materials. Multiphase culture-independent technology were employed in this study, including nested PCR-denaturing gradient gel electrophoresis (nested PCR-DGGE), phospholipid fatty acid (PLFA), phospholipid ether lipids (PLEL) and fluorescence in situ hybridization (FISH) analysis. Results suggested that the microbial diversity significantly changed under environmental stress and different culture patterns during APMs cultivation. The dominant bacteria in APMs mainly fell into Clostridiales, Lactobacillales, Bacteroidales and Rhizobiales, Archaea affiliated with Methanomicrobiales and Methanosarcinales, and fungi belonged to Saccharomycetales and Eurotiales. Furthermore, the microbial community structures of APMs cultured by ground pile pattern were more similar with that of aged pit muds, meanwhile, the relative bands intensities of microbes, which are the main contributors for liquor brewing, increased with the culture times. Not only the niche selection and biogeochemical properties of APMs, but also the mutual collaboration and constraint between different microbes may result in enriching different liquor-brewing microbes into APMs. APM cultivation technology was necessary to promote enriching functional liquor-brewing microbes into APMs. These results may facilitate understanding the microbial succession during APMs manufacture. © 2015 The Society for Applied Microbiology.

Antioxidant Activity of Chinese Shanxi Aged Vinegar and Its Correlation with Polyphenols and Flavonoids During the Brewing Process.

Science.gov (United States)

Xie, Xiaolin; Zheng, Yu; Liu, Xian; Cheng, Cheng; Zhang, Xianglong; Xia, Ting; Yu, Songfeng; Wang, Min

2017-10-01

One of the most famous Chinese vinegars, Shanxi aged vinegar (SAV), is produced with solid-state fermentation technology. Total antioxidant activity (TAC) is a special property for SAV. In this study, we investigate correlations between total antioxidant activity (TAC) and total polyphenol (TP) and total flavonoid (TF) contents of SAV, especially during the brewing process. For SAV, TAC, TP, and TF increased with the increase of aging time. The correlation coefficients between TAC and TP were 0.869 and 0.934, respectively, when analyzed with the method of ABTS and FRAP. They were 0.828 (ABTS) and 0.877 (FRAP) between the TAC and TF. In smoking pei stage that is a special technique for SAV different from other Chinese cereal vinegars, TAC increased by 120% (ABTS) and 111% (FRAP) mainly due to the increase of TP (89%) and TF (75%), which was more obvious than that during alcohol fermentation and acetic acid fermentation stages. Moreover, variation during brewing process of 8 main polyphenol compounds that were proved responsible for the TAC of SAV was analyzed. In addition to catechins and chlorogenic acid, gallic acid serves as one of the principal antioxidant ingredients in SAV. Total antioxidant activity (TAC) of Shanxi aged vinegar (SAV), which is highly correlated with total polyphenol and total flavonoid, increased with aging time, however, there is a little loss of total antioxidant after more than 8 y. During the brewing process smoking pei technique is important for enhancing the TAC of SAV suggesting critical controlled and thoroughly study of smoking pei stage are needed to improve the quality of SAV. © 2017 Institute of Food Technologists®.

Fructanase and fructosyltransferase activity of non-Saccharomyces yeasts isolated from fermenting musts of Mezcal.

Science.gov (United States)

Arrizon, Javier; Morel, Sandrine; Gschaedler, Anne; Monsan, Pierre

2012-04-01

Fructanase and fructosyltransferase are interesting for the tequila process and prebiotics production (functional food industry). In this study, one hundred thirty non-Saccharomyces yeasts isolated from "Mezcal de Oaxaca" were screened for fructanase and fructosyltransferase activity. On solid medium, fifty isolates grew on Agave tequilana fructans (ATF), inulin or levan. In liquid media, inulin and ATF induced fructanase activities of between 0.02 and 0.27U/ml depending of yeast isolate. High fructanase activity on sucrose was observed for Kluyveromyces marxianus and Torulaspora delbrueckii, while the highest fructanase activity on inulin and ATF was observed for Issatchenkia orientalis, Cryptococcus albidus, and Candida apicola. Zygosaccharomyces bisporus and Candida boidinii had a high hydrolytic activity on levan. Sixteen yeasts belonging to K. marxianus, T. delbrueckii and C. apicola species were positive for fructosyltransferase activity. Mezcal microbiota proved to showed to be a source for new fructanase and fructosyltransferases with potential application in the tequila and food industry. Copyright © 2012 Elsevier Ltd. All rights reserved.

Indole-3-Acetic Acid-Producing Yeasts in the Phyllosphere of the Carnivorous Plant Drosera indica L

Science.gov (United States)

Shin, Li-Ying; Wei, Jyuan-Yu; Fu, Shih-Feng; Chou, Jui-Yu

2014-01-01

Yeasts are widely distributed in nature and exist in association with other microorganisms as normal inhabitants of soil, vegetation, and aqueous environments. In this study, 12 yeast strains were enriched and isolated from leaf samples of the carnivorous plant Drosera indica L., which is currently threatened because of restricted habitats and use in herbal industries. According to similarities in large subunit and small subunit ribosomal RNA gene sequences, we identified 2 yeast species in 2 genera of the phylum Ascomycota, and 5 yeast species in 5 genera of the phylum Basidiomycota. All of the isolated yeasts produced indole-3-acetic acid (IAA) when cultivated in YPD broth supplemented with 0.1% L-tryptophan. Growth conditions, such as the pH and temperature of the medium, influenced yeast IAA production. Our results also suggested the existence of a tryptophan-independent IAA biosynthetic pathway. We evaluated the effects of various concentrations of exogenous IAA on yeast growth and observed that IAA produced by wild yeasts modifies auxin-inducible gene expression in Arabidopsis. Our data suggest that yeasts can promote plant growth and support ongoing prospecting of yeast strains for inclusion into biofertilizer for sustainable agriculture. PMID:25464336

Proteases and caspase-like activity in the yeast Saccharomyces cerevisiae.

Science.gov (United States)

Wilkinson, Derek; Ramsdale, Mark

2011-10-01

A variety of proteases have been implicated in yeast PCD (programmed cell death) including the metacaspase Mca1 and the separase Esp1, the HtrA-like serine protease Nma111, the cathepsin-like serine carboxypeptideases and a range of vacuolar proteases. Proteasomal activity is also shown to have an important role in determining cell fate, with both pro- and anti-apoptotic roles. Caspase 3-, 6- and 8-like activities are detected upon stimulation of yeast PCD, but not all of this activity is associated with Mca1, implicating other proteases with caspase-like activity in the yeast cell death response. Global proteolytic events that accompany PCD are discussed alongside a consideration of the conservation of the death-related degradome (both at the level of substrate choice and cleavage site). The importance of both gain-of-function changes in the degradome as well as loss-of-function changes are highlighted. Better understanding of both death-related proteases and their substrates may facilitate the design of future antifungal drugs or the manipulation of industrial yeasts for commercial exploitation.

Processing of nonedible plant wastes to obtain furfural and yeasts

Energy Technology Data Exchange (ETDEWEB)

Golowin, W.W.

1977-01-01

The technology of furfural and yeast production from hydrolyzates of wastes from the food and wood-processing industries is detailed. For furfural manufacturing, the pentosan-containing raw material is treated with H/sub 2/SO/sub 4/ and steam-hydrolyzed, the furfural-containing vapors are condensed and separated from non-condensing gases, and the furfural is isolated from the condensate, purified and stabilized. After the furfural hydrolysis, the pressure is decreased from 3 to 1.2 atm, a 0.5% H/sub 2/SO/sub 4/ solution is added, and a hexose-containing hydrolyzate is transferred for neutralization and yeast culturing.

Heterologous transporter expression for improved fatty alcohol secretion in yeast

DEFF Research Database (Denmark)

Hu, Yating; Zhu, Zhiwei; Nielsen, Jens

2017-01-01

The yeast Saccharomyces cerevisiae is an attractive host for industrial scale production of biofuels including fatty alcohols due to its robustness and tolerance towards harsh fermentation conditions. Many metabolic engineering strategies have been applied to generate high fatty alcohol production...... transporters tested, human FATP1 was shown to mediate fatty alcohol export in a high fatty alcohol production yeast strain. An approximately five-fold increase of fatty alcohol secretion was achieved. The results indicate that the overall cell fitness benefited from fatty alcohol secretion and that the acyl......-CoA synthase activity of FATP1 contributed to increased cell growth as well. This is the first study that enabled an increased cell fitness for fatty alcohol production by heterologous transporter expression in yeast, and this investigation indicates a new potential function of FATP1, which has been known...

Drinking pattern and its relation to hemoglobin concentration in local brew consumers from the Kathmandu Region

Institute of Scientific and Technical Information of China (English)

Arun Kumar

2009-01-01

The study was conducted to determine the hemoglobin concentration in alcohol consumers (home made brew-Chang) and compare it with non- alcohohcs healthy subjects. Hemoglobin (Hb) concentration was determined in 2053 alcoholic consumers (males: 1056; females: 997) and was compared with 1 027 (males: 623; females: 404) healthy non-alcoholic con-trol subjects. The Hb concentration in alcoholic male and female were 13.42 ± 2.14 g/dL and 12.19 ± 1.55 g/dL compared with control showing 14.43 ± 1.07 g/dL and 12.73 ± 1.41 g/dL in males and females respectively. The differences in Hb concentration between alcoholic and non- alcoholic consumers were highly significant in both genders with a P value of 0. 000 674 in males and 0.004 732 in females. Alcohol Use Disorders Identification test (AUDIT) scores was advocated to alcoholic consum-ers to test the severity of drunkenness and disorders related to it. A total of 887 males and 663 females crossed the cut-off limits of ≥8 AUDIT scores showing the addiction towards drinking habits of local brew.

Selection and Characterization of Potential Baker's Yeast from Indigenous Resources of Nepal.

Science.gov (United States)

Karki, Tika B; Timilsina, Parash Mani; Yadav, Archana; Pandey, Gyanu Raj; Joshi, Yogesh; Bhujel, Sahansila; Adhikari, Rojina; Neupane, Katyayanee

2017-01-01

The study aims to isolate the yeast strains that could be used effectively as baker's yeast and compare them with the commercial baker's yeast available in the market of Nepal. A total of 10 samples including locally available sources like fruits, Murcha, and a local tree "Dar" were collected from different localities of Bhaktapur, Kavre, and Syangja districts of Nepal, respectively. Following enrichment and fermentation of the samples, 26 yeast strains were isolated using selective medium Wallerstein Laboratory Nutrient Agar. From the differential tests which included morphological and microscopic observation and physiological and biochemical characterization such as nitrate reduction and lactose utilization tests, 8 strains were selected as possible Saccharomyces strain. The selected strains were further assessed for their efficient leavening ability by tests such as ethanol tolerance, osmotolerance, invertase test, and stress exclusion test. The three most potent strains ENG, MUR3B, and SUG1 isolated from grape, Murcha, and sugarcane, respectively, were used in the fermentation and baking of dough. These strains also carried a possibility of being used as industrial baker's yeast.

Radiation stimulation of yeast crops for increasing output of alcohol and baker yeasts

International Nuclear Information System (INIS)

Vlad, E.; Marsheu, P.

1974-01-01

The purpose of this study was to stimulate by gamma radiation the existing commercial types of yeast so as to obtain yeasts that would better reflect the substrate and have improved reproductive capacity. The experiments were conducted under ordinary conditions using commercial yeasts received from one factory producing alcohol and bakery yeasts and isolated as pure cultures. Irradiating yeast cultures with small doses (up to 10 krad) was found to stimulate the reproduction and fermenting activity of yeast cells as manifested in increased accumulation of yeast biomass and greater yield of ethyl alcohol. (E.T.)

Influence of different yeast/lactic acid bacteria combinations on the aromatic profile of red Bordeaux wine.

Science.gov (United States)

Gammacurta, Marine; Marchand, Stéphanie; Moine, Virginie; de Revel, Gilles

2017-09-01

The typical fruity aroma of red Bordeaux wines depends on the grape variety but also on microbiological processes, such as alcoholic and malolactic fermentations. These transformations involve respectively the yeast Saccharomyces cerevisiae and the lactic acid bacterium Oenococcus oeni. Both species play a central role in red winemaking but their quantitative and qualitative contribution to the revelation of the organoleptic qualities of wine has not yet been fully described. The aim of this study was to elucidate the influence of sequential inoculation of different yeast and bacteria strains on the aromatic profile of red Bordeaux wine. All microorganisms completed fermentations and no significant difference was observed between tanks regarding the main oenological parameters until 3 months' aging. Regardless of the yeast strain, B28 bacteria required the shortest period to completely degrade the malic acid, compared to the other strain. Quantification of 73 major components highlighted a specific volatile profile corresponding to each microorganism combination. However, the yeast strain appeared to have a predominant effect on aromatic compound levels, as well as on fruity aroma perception. Yeasts had a greater impact on wine quality and have more influence on the aromatic style of red wine than bacteria. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Breeding of Freeze-tolerant Yeast and the Mechanisms of Stress-tolerance

Science.gov (United States)

Hino, Akihiro

Frozen dough method have been adopted in the baking industry to reduce labor and to produce fresh breads in stores. New freeze-tolerant yeasts for frozen dough preparations were isolated from banana peel and identified. To obtain strains that have fermentative ability even after several months of frozen storage in fermented dough, we attempted to breed new freeze-tolerantstrain. The hybrid between S.cerevisiae, which is a isolated freeze-tolerant strain, and a strain isolated from bakers' yeast with sexual conjugation gave a good quality bread made from frozen dough method. Freeze-tolerant strains showed higher surviving and trehalose accumulating abilities than freeze-sensitive strains. The freeze tolerance of the yeasts was associated with the basal amount of intracellular trehalose after rapid degradation at the onset of the prefermentation period. The complicated metabolic pathway and the regulation system of trehalose in yeast cells are introduced. The trehalose synthesis may act as a metabolic buffer system which contribute to maintain the intracellular inorganic phosphate and as a feedback regulation system in the glycolysis. However, it is not known enough how the trehalose protects yeast cells from stress.

An engineered yeast efficiently secreting penicillin.