Bottom Fermentation Research Articles

FLOCCULENCE OF BREWERY YEASTS AND THEIR SURFACE PROPERTIES: CHEMICAL COMPOSITION, ELECTROSTATIC CHARGE AND HYDROPHOBICITY

The flocculence of a top and a bottom fermentation brewery yeast was studied through the cell surface properties: surface composition (X-ray photoelectron spectroscopy), surface charge (microelectrophoresis) and hydrophobicity (adhesion tests). Aerobic Cultures and fermentation simulating industrial conditions were performed. The flocculence (tendency to flocculate in favourable conditions) has been determined by a test which separated the occurrence of flocculation and the measurement of its manifestation (suspension clearing); the flocculating agents were ethanol and calcium. The top fermentation strain does not flocculate with calcium alone but is very sensitive to ethanol (0.01% (v/v)). The lower flocculence observed for cells cultured on malt extract as compared with cells cultured on yeast extract is accompanied by a more negative zeta potential. The bottom fermentation strain which has a more negative surface flocculates only in the presence of calcium but ethanol enhances the process. The variation of flocculence according to the culture medium and harvesting time is correlated to the variation of the phosphate surface concentration. This is not paralleled by a variation of the zeta potential which does not decrease below a value of about-35 mV as the phosphate surface concentration increases. The increase of flocculence as a function of culture time correlates also with an increase of the cell hydrophobicity; this is more obvious for the cultures than for the fermentations.

Surface properties of Saccharomyces cerevisiae and Saccharomyces carlbergensis: chemical composition, electrostatic charge and hydrophobicity

The surface composition of nine top and bottom fermentation brewery strains was determined by X-ray photoelectron spectroscopy. Individual strains differ mainly in the minor constituents phosphate, ammonium and potassium. These surface concentrations are approximately twice as high for the bottom strains as compared to the top strains. The surface charge was studied by electrophoretic mobility. At pH 4, the bottom strains are more negative ( −35 ± 5 mV) than the top strains ( −12 ± 9 mV). The zeta potential at pH 4 is correlated with the phosphate surface concenration. There is a linear 1 to 1 relationship of phosphate with potassium and with ammonium, indicating that these cations are the main counterions of the cell surface. Phosphates play a predominant role in the development of the surface charge and the participation of carboxylic groups is minor. The hydrophobicity, estimated by the water contact angle, is correlated with the N/P surface concentration ratio. The bottom strains are less hydrophobic than the top strains. Surface charge and hydrophobicity could account for the behaviour of top and bottom strains in fermentation. The study of a non-brewing strain ( Saccharomyces cerevisiae) shows that the systematic differences of surface properties found between top and bottom fermentation strains cannot be generalised to S. cerevisiae and Saccharomyces carlsbergensis.

DNA sequence polymorphisms in the genus Saccharomyces IV. Homoeologous chromosomes III of Saccharomyces bayanus, S. carlsbergensis, and S. uvarum

Single chromosome III transfers have been accomplished from the two species S. bayanus and S. uvarum into genetically marked S. cerevisiae strains. Incompabilities between S. bayanus or S. uvarum, and S. cerevisiae strains may account for the very few chromosome addition lines obtained. The preliminary genetic map for S. bayanus chromosome III is similar to the genetic map for a S. carlsbergensis chromosome III from Danish lager strain BK2208. Recombination is absent between the transferred chromosomes and the auxotrophically marked chromosome from S. cerevisiae in the intervalHIS4 toLEU2 but recombination does occur in the intervalLEU2 toTHR4. The mapped S. bayanus chromosome III carriesHIS4 pattern III while the mapped chromosome III from the lager strain containsHIS4 pattern II. Transfer of a chromosome III from S. uvarum to S. cerevisiae has been recognised by restriction endonuclease fragment patterns, OFAGE chromosome separations and molecular hybridization, but a genetic map could not be constructed for an S. uvarum chromosome due to instability of the chromosome addition lines. The hypothesis is put forward that the S. carlsbergensis type strain and the lager strains are sibling species and species hybrids both produced by hybridization of an S. cerevisiae top fermenting strain and the bottom fermenting strain S. monacensis. The lager strains and the authentic type strain are designated S. carlsbergensis. From the electrophoretic karyotypes of type strains of Saccharomyces and molecular hybridization patterns it is deduced that S. bayanus, S. inusitatus, S. pastorianus and S. uvarum are closely related but distinet from the bottom fermenting strains.

DNA sequence polymorphisms in the genus saccharomyces III. Restriction endonuclease fragment patterns of chromosomal regions in brewing and other yeast strains

30 bottom fermenting strains, 13 hybrid lager strains, 11 top fermenting strains. In addition, 24 other yeast species and strains have been analysed in this study. Four DNA regions have been monitored by restriction endonuclease fragment pattern polymorphisms. The regions analysed are:RDN1 (encoding cytosolic ribosomal RNA molecules) located on chromosome XII in S. cerevisiae,HIS4 (histidine 4) andLEU2 (leucine 2) both located on chromosome III and theTy elements which are distributed at different positions in the genome of S. cerevisiae. SevenTy fragment patterns have been detected in the bottom fermenting strains. Patterns I, II, IIa, IIb, and IIc are present in lager strains while pattern III and IV are found in S. carlsbergensis bottom fermenting strain No. I and in S. monacensis, respectively. Hybridization of theTy1 p14 probe from S. cerevisiae to OFAGE separated chromosomes from bottom fermenting strains show that at least fiveTy elements are present in the genomes of the lager strains, at least five in S. carlsbergensis bottom fermenting strain No. I and at least three in S. monacensis. From the restriction fragment patterns and the karyotypes of the bottom fermenting strains it is suggested that these strains are closely related and different from the S. bayanus, S. pastorianus, and S. uvarum group as well as from the S. cerevisiae strains. In spite of their differences inTy element patterns the large strains are so homogenous that most likely they all originate from a single strain which is related to S. carlsbergensis and S. monacensis type strains. In contrast to the bottom fermenting strains there is a large variability among the top fermenting strains, especially with regard to theLEU2 gene andTy elements. It seems that S. bayanus, S. inusitatus, S. pastorianus, S. validus, and S. uvarum are closely related, and none of the studied strains from these taxons contained DNA which hybridized to theTy1 probe from S. cerevisiae. This is a clear difference from the DNA of bottom fermenting strains which consistently hybridized strongly to theTy1 probe.

DNA sequence polymorphisms in the genus Saccharomyces. II. Analysis of the genesRDN1, HIS4, LEU2 andTy transposable elements in Carlsberg, Tuborg and 22 bavarian brewing strains

The genotypes of the Carlsberg and Tuborg bottom fermenting (lager) Saccharomyces strains as well as those of 13 other bottom fermenting yeasts and 9 top fermenting yeasts from the collection of the Wissenschaftliche Station fur Brauerei in Munich were analysed fro restriction fragment length differences in theRDN1 ribosomal RNA gene cluster on chromosome XII as well as in the chromosome III regions containing theHIS4 (histidine 4) andLEU2 (leucine 2) genes. All brewing strains had the same form IIRDN1 gene cluster. The top fermenting strains yielded identical Sall restriction endonuclease fragment patterns (I) when probed with theHIS4 gene probe of plasmid pC503. The pattern corresponds to that found in genetic standard strain S288C. The bottom fermenting strains were all heterozygous for theHIS4 patterns I and II known to originate from homeologous regions of two chromosomes.Molecular hybridisation of aLEU2 gene probe to Sall restricted DNA of the bottom fermenting yeast strains gave identical fragment patterns (III+IV), while a pattern designated II+III was most common in top fermenting strains. Two additional patterns were found among the latter.The transposable elementTy1 from a genetic standard strain distinguishes the genotypes of various lager strains as well as those of top fermenting yeasts. Hybridisation ofTy1 to EcoRI restricted DNA of Carlsberg lager strain BK 2246 yields four diagnostic fragments, while the DNA of Tuborg lager strain BK 2224 is characterized by an additional 5.5 kb fragment. Conversely Sall restricted DNA of the Carlsberg strain contains a 10 kb fragment absent from the genome of the Tuborg strain. Three different restriction fragment patterns are found after probing with theTy1 element among the Bavarian bottom fermenting yeasts. More complex patterns with at least 10 restriction fragments hybridising to theTy1 element are found among the top fermenting strains from the Munich collection. Five different genotypes have been identified among 9 strains tested.Ty1 transposing elements will be helpful markers in the characterisation of improved brewing strains.

Provozní zkoušky jednofázové výroby piva v prototypových cylindrokónických tancích.

Provozní zkoušky jednofázové výroby piva v prototypových cylindrokónických tancích.

FORMATION OF HIGHER ALCOHOLS BY VARIOUS YEASTS

The formation of higher alcohols by various yeasts has been studied as a function of the nitrogen level of the medium. Two types of substrate were used. In one ammonium sulphate was the sole nitrogen source and in the other a complex amino acid mixture simulating that present in brewery wort was used. In the former medium, the patterns exhibited by the yeasts were all very much alike, indicating that the formation of higher alcohols through the biosynthetic activities of yeasts is always basically similar. In the medium containing a complex mixture of amino acids, where the higher alcohols can be formed partly or entirely from the exogenous amino acids through Ehrlich's mechanism, widely different patterns were observed, indicating that the utilization of exogenous amino acids as a source of nitrogen and the extent of regulation of biosynthetic pathways vary with species and strain. All the brewery strains seem to be rather similar and no distinct differences between top and bottom fermentation strains could be observed.

THE ADSORPTION OF HOP SUBSTANCES ON THE YEAST CELL WALL

The adsorption of hop substances on to the yeast cell wall, as distinct from the total loss during fermentation, followed the classical pattern of the Freundlich adsorption isotherm with both top and bottom fermentation yeasts. In order to avoid adventitious contamination of the yeasts by hop compounds during head formation, the fermentations were not fully attenuated. The three yeasts adsorbed closely similar proportions of hop substances from fermenting worts of the same composition, but the actual amount differed from one series of fermentations to another. The losses of bitter compounds during the fermentations were only partly accounted for by adsorption on the yeast.

HOP SUBSTANCES AND YEAST BEHAVIOUR

Top fermentation yeast strains vary in their ability to form a yeast head in the absence of hop substances. However, the addition of isohumulone or humulone to unhopped wort stimulates yeast-head formation. A quantitative method for the estimation of hop substances bound to the yeast cell is described and is used to demonstrate that in top fermentation, most of the adsorbed bitter substances are present in the head. It is shown that most of the hop substances in the yeast head are transported there by bubbles of carbon dioxide; in bottom fermentation, considerable quantities are present in the surface foam. In comparison with hopped wort the fermentation of unhopped wort with Saccharomyces cerevisiae (N.C.Y.C. 240) is characterized by an increased amount of yeast in suspension during fermentation, although there is no increase in the rate of attenuation.

High molecular compounds from yeast: III. Top yeast. A comparative study

1. 1. A comparative study has been made on the constituents of top and bottom fermentation brewing yeast. 2. 2. Top yeast, dried according to the Lebedev method, showed an insignificative protein extractibility. 3. 3. Ground top and bottom yeast showed an equal protein extractibility, and similar sedimentation diagrams. 4. 4. Some compounds, isolated from intact top yeast, showed the same properties as were determined for constituents of the cell wall of bottom yeast. 5. 5. On the cell surface of top yeast were found readily extractable proteins as permanent constituents, which did not occur in bottom fermentation yeast.

Gärung und phytochemische reduktion

In connection with consideration about the origin, behaviour, and significance of C 3-substances, particularly free as well as phosphorylaed trioses, it has been shown that: Ordinary top and bottom fermentation yeasts, which do not ferment dihydroxyacetone or glyceraldehyde, effect no phytochemical reduction of the two trioses to glycerol. The C 3-sugars are unchanged. They are not toxic to yeast in concentrations of 1%, nor they inhibit the smooth fermentation of added zymohexoses. The resistance of the trioses to phytochemical reduction is noteworthy insofar as the desoxytrioses, monohydroxyacetone and lactic aldehyde, just like the triose anhydride, methylglyoxal, are reduced to propylene glycol (which is closely related to glycerol) under comparable conditions. The yeasts used have been found to be entirely suitable for bioreductions. They convert cyclopentanone into cyclopentanol, d, and d, l-camphorquinone by bioreduction of a carbonyl group into hydroxycamphor, and isocaproic aldehyde into 2-methylpentanol-1. As soon as the possibility exists, the pytochemical reduction takes an asymmetric course. This has now been carried out in the cyclopentane series with a diketone of the hydroaromatic series.

Some nitrogenous constituents of wort and their fate during fermentation by top and bottom fermentation yeasts

A quantitative examination of the more important nitrogenous groupings present in wort, e.g., ammonia N, amino acid N, asparagine N, residual N and protein N have been made, and their fate in fermentation by top and bottom-yeasts followed. The presence of 18 individual free amino acids has been detected in wort and the behaviour of 16 during fermentation by top and bottom-yeasts followed by microbiological assay. Seven “essential” amino acids in yeast protein have been determined. The yeast was grown on media containing different sources of nitrogen. With the exception of methionine, all the acids were constant in amount whatever the nature of the medium. The concentration of methionine in yeast protein could be increased by increasing its concentration in the medium.

TOP AND BOTTOM FERMENTATION SYSTEMS AND THEIR RESPECTIVE BEER CHARACTERISTICS

Journal of the Institute of BrewingVolume 52, Issue 4 p. 174-181 Free Access TOP AND BOTTOM FERMENTATION SYSTEMS AND THEIR RESPECTIVE BEER CHARACTERISTICS Prof. B. Jelinek D.Sc., M.D. (Brno.), Prof. B. Jelinek D.Sc., M.D. (Brno.)Search for more papers by this author Prof. B. Jelinek D.Sc., M.D. (Brno.), Prof. B. Jelinek D.Sc., M.D. (Brno.)Search for more papers by this author First published: July‐August 1946 https://doi.org/10.1002/j.2050-0416.1946.tb01579.xCitations: 2AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume52, Issue4July‐August 1946Pages 174-181 RelatedInformation

THE NUTRITIVE SIGNIFICANCE OF THE AMINO ACIDS

ArticlesTHE NUTRITIVE SIGNIFICANCE OF THE AMINO ACIDSWilliam C. RoseWilliam C. RosePublished Online:01 Jan 1938https://doi.org/10.1152/physrev.1938.18.1.109MoreSectionsPDF (4 MB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInEmail Previous Back to Top FiguresReferencesRelatedInformationCited ByComparative effects of acute-methionine loading on the plasma sulfur-amino acids in NAC-supplemented HIV+ patients and healthy controls1 February 2018 | Amino Acids, Vol. 50, No. 5Microencapsulation of crystalline-methionine enclosed with gelatine and sodium alginate by spray-drying30 May 2015 | Materials Research Innovations, Vol. 19, No. sup5ASAS Centennial Paper: Landmark discoveries in swine nutrition in the past century12Journal of Animal Science, Vol. 87, No. 2Properties and Reactions of Indoles, Isoindoles, and Their Hydrogenated Derivatives2 January 2008The Pharmacodynamics of L-ArginineThe Journal of Nutrition, Vol. 137, No. 6β-Leucine and the β-Keto Pathway of Leucine Metabolism22 November 2006Minimum methionine requirement and cysteine sparing of methionine in healthy school-age childrenThe American Journal of Clinical Nutrition, Vol. 84, No. 5The In Vivo Sparing of Methionine by Cysteine in Sulfur Amino Acid Requirements in Animal Models and Adult HumansThe Journal of Nutrition, Vol. 136, No. 6A 45-Year Obsession and Passionate Pursuit of Optimal Nutrition Support: Puppies, Pediatrics, Surgery, Geriatrics, Home TPN, A.S.P.E.N., Et Cetera5 January 2017 | Journal of Parenteral and Enteral Nutrition, Vol. 29, No. 4Exercise-induced immunodepression– plasma glutamine is not the linkNatalie Hiscock, and Bente Klarlund Pedersen1 September 2002 | Journal of Applied Physiology, Vol. 93, No. 3Current Indications for Intravenous Nutritional Support in Oncology PatientsSurgical Oncology Clinics of North America, Vol. 4, No. 3Balanced amino acid composition essential for infusion-induced egg development in the mosquito (Culex pipiens pallens)Journal of Insect Physiology, Vol. 39, No. 7Enteral glutamine supports hepatic glutathione efflux during inflammationThe Journal of Nutritional Biochemistry, Vol. 4, No. 4Amino acid imbalance, a nutritional model: Serotonin3 mediation of aversive responsesPhysiology & Behavior, Vol. 49, No. 5A new rapid enzyme digestion method for predicting in Vitro protein quality (PDD index)Food Chemistry, Vol. 32, No. 4AMINOACIDS: ESSENTIAL AND NON-ESSENTIAL?The Lancet, Vol. 321, No. 8332Branched chain amino acid metabolism in two avian species: Coturnix Coturnix japonica and Gallus domesticusComparative Biochemistry and Physiology Part B: Comparative Biochemistry, Vol. 69, No. 2The essential amino acid requirements of the Dungeness crab, Cancer magisterAquaculture, Vol. 7, No. 3Possibilities and necessities of parenteral nutrition with amino acid mixtures1 June 1975 | Zeitschrift für Ernährungswissenschaft, Vol. 14, No. 2Amino acid metabolism of Astacus leptodactylus (Esch.)—II. 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Metabolic activity in vitroBiochimica et Biophysica Acta, Vol. 74Nutritional requirements of insects associated with animal parasitismExperimental Parasitology, Vol. 7, No. 6Pseudomembranous EnterocolitisThe Lancet, Vol. 264, No. 6831Nutrition of VegetariansThe Lancet, Vol. 264, No. 6831Significance of dietary supplementation in surgical casesThe American Journal of Surgery, Vol. 77, No. 4Some nitrogenous constituents of wort and their fate during fermentation by top and bottom fermentation yeastsBiochimica et Biophysica Acta, Vol. 3Problems of parenteral nutritionThe American Journal of Medicine, Vol. 5, No. 5Utilization of protein hydrolysates by normal and protein-depleted animalsThe American Journal of Medicine, Vol. 5, No. 3Effect of injury and disease on nitrogen metabolismThe American Journal of Medicine, Vol. 5, No. 1UTERINE GRAFT OPERATION FOR GENITAL PROLAPSEThe Lancet, Vol. 245, No. 6340BRITISH ORTHOPAEDIC ASSOCIATIONThe Lancet, Vol. 242, No. 6274I. Evaluation of the peanut as a cash crop II. Importance of the peanut from a biochemical standpoint, especially from that of nutritionJournal of the Franklin Institute, Vol. 234, No. 3Some Current Problems and Recent Advances in the Chemistry of the Proteins27 July 2018 | Proceedings. Annual meeting - American Society of Brewing Chemists, Vol. 3, No. 1 More from this issue > Volume 18Issue 1January 1938Pages 109-136 https://doi.org/10.1152/physrev.1938.18.1.109History Published online 1 January 1938 Published in print 1 January 1938 PDF download Metrics Downloaded 2,096 times

British Food Journal Volume 36 Issue 8 1934

In considering the lager beer industry of Denmark it may not seem out of place to recall the main facts regarding the researches of E. C. Hansen. It is due to Hansen, a Dane, that the brewing industry throughout the world was placed on a scientific basis so far as the employment of pure yeast cultures is concerned. The brewing of lager beer had been for long successfully practised in certain European countries, notably in Germany. In a word what may be termed the mechanical technik was well understood, but a knowledge of the underlying biological principles so far as they related to the nature and action of the yeast employed had not advanced so far. The study of micro‐organisms in general had but just commenced. Their very existence in many cases was not even suspected. The employment of yeast in brewing practice was largely of the “hit and miss” kind, and continued to be so until fifty years ago. It is true, of course, that excellent beer was being made in this country and on the continent, both top and bottom fermentation kinds, as it had been for centuries past, but the power to control the nature of the beer by using a pure culture of a selected variety of yeast was not possible until Hansen had made his investigations and published the results in 1883.

British Food Journal Volume 36 Issue 5 1934

Lager beer is a bottom fermentation beer which is characterised by having in general a low alcohol content and a high proportion of extractive matters in comparison with the top fermentation beer that is still, by far, the main brew of this country. It may be pointed out that in the top fermentation process the variety of yeast which is used rises to the top of the liquid in the fermentation vat. In the bottom process the yeast sinks to the bottom, and fermentation takes place at a lower temperature. Lager has been described, among other things, as “liquid food” as an aperitif; as a non‐intoxicant. It would therefore seem to possess a rare combination of good qualities. While we submit that excessive praise may be sometimes almost as effective as an agent of damnation as faint praise, there is no doubt that genuine lager beer is a thoroughly wholesome drink.