1887

Abstract

The flocculation of a strain of brewers' yeast was absolutely dependent upon the presence of calcium; a concentration of 200 mm-CaCl was sufficient to ensure almost complete flocculation. No other metal could replace calcium; several metals aggregated potentially flocculent cells but also aggregated non-flocculent cells. Sodium ions antagonized the action of the calcium. The effects of pH value and esterification suggested that carboxyl groups were involved. The flocs had a ‘melting temperature’ of 50–60° and were dispersed by urea, suggesting that hydrogen bonds were also present.

Non-flocculent yeast was aggregated when the dielectric constant of the medium was decreased by the addition of organic solvents, but this aggregation was also dependent on the presence of traces of calcium. Conversely, increase of the dielectric constant of the medium, by adding formamide, dispersed flocculent yeast. Certain specific sugars also dispersed flocculent yeast. It is suggested that flocculent yeast cells are linked by salt bridges formed by calcium atoms joined with two carboxyl groups in the surfaces of different cells and that this structure is stabilized by hydrogen bonds formed between complementary patterns of carbohydrate hydrogens and hydroxyls in the cell surfaces.

Loading

Article metrics loading...

/content/journal/micro/10.1099/00221287-35-1-61
1964-04-01
2022-05-21
Loading full text...

Full text loading...

/deliver/fulltext/micro/35/1/mic-35-1-61.html?itemId=/content/journal/micro/10.1099/00221287-35-1-61&mimeType=html&fmt=ahah

References

  1. Doty P. 1996; The relation of the interaction of polynucleotides to the secondary structure of nucleic acids. In ‘The Structure and Biosynthesis of Macromolecules’.. Biochem. Soc. Symp. 21:8
    [Google Scholar]
  2. Eddy A.A. 1955a; Flocculation characteristics of yeasts. 11. Sugars as dispersing agents.. J. Inst. Brew. 61:313
    [Google Scholar]
  3. Eddy A.A. 1955b; Flocculation characteristics of yeasts. 111. General role of flocculating agents and special characteristics of a yeast flocculated by alcohol.. J. Inst. Brew. 61:318
    [Google Scholar]
  4. Fraenkel-Conrat H. 1944; Action of 1,2-epoxides on proteins.. J. biol. Chem. 154:247
    [Google Scholar]
  5. Harris J.O. 1959; Possible mechanism of yeast flocculation.. J. Inst. Brew. 65:5
    [Google Scholar]
  6. Hartong B.D. 1951; Flocculation of yeast in breweries.. Proc. European Brezeerp Convention Congr. Brightma, p.10
    [Google Scholar]
  7. Jansen H.E., Mendlik F. 1951; A study on yeast flocculation.. Proc. Eztropeun Brmery Convention Congr. Brighton, p.59
    [Google Scholar]
  8. Jansen H.E., Mendlik F. 1953; A study on yeast flocculation II. Proc. European Brewery Convention Congr. Nice, p.143
    [Google Scholar]
  9. Lindquist W. 1953; On the mechanism of yeast flocculation.. J. Inst. Brew. 59:59
    [Google Scholar]
  10. Masschelein C., Devreux A. 1957; Flocculence et structure de la paroi cellulaire de la levure.. Proc. European Brewery Convention Congr. Copenhagen194
    [Google Scholar]
  11. Mill P.J. 1964; The effect of nitrogenous substances on the time of flocculation of Saccharomyces cerevisiae. . J. gen. Microbiol. 35:53
    [Google Scholar]
  12. Northcote D.H., Horne R.W. 1952; The chemical composition and structure of the yeast cell wall.. Biochem. J. 51:232
    [Google Scholar]
  13. St Johnston J.H. 1949; The flocculation of proteins in wort and beer.. Proc. European Brmery Convention Cmagr. Lucerne62
    [Google Scholar]
  14. Trolle B. 1950; Experiments on bottom fermentation. 111. The quantity of suspended yeast during fermentation as a function of carbon dioxide fermentation under different conditions.. J. Inst. Brew. 56:364
    [Google Scholar]
  15. Verzar F. 1963; The aging of collagen.. Sci. Amer. 208:4104
    [Google Scholar]
http://instance.metastore.ingenta.com/content/journal/micro/10.1099/00221287-35-1-61
Loading
/content/journal/micro/10.1099/00221287-35-1-61
Loading

Data & Media loading...

Most cited this month Most Cited RSS feed

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error