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MATHEMATICAL REPRESENTATION OF THE COURSE OF YEAST GROWTH
Author(s) -
Thorne R. S. W.
Publication year - 1939
Publication title -
journal of the institute of brewing
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.523
H-Index - 51
eISSN - 2050-0416
pISSN - 0046-9750
DOI - 10.1002/j.2050-0416.1939.tb05974.x
Subject(s) - yeast , logistic function , growth rate , simple (philosophy) , autolysis (biology) , exponential growth , biology , biological system , statistics , mathematics , econometrics , biochemistry , mathematical analysis , geometry , philosophy , epistemology , enzyme
Quantitative studies of yeast growth frequently involve the examination and comparison of the well‐known S‐shaped curves which picture the course of yeast growth on a time basis. Such studies would be facilitated if these curves could be represented with fair accuracy by a simple mathematical relationship. Further, the extent of the obedience of yeast growth to any relationship thus deduced might itself throw light on the underlying laws of yeast growth. The growth of yeast in synthetic media was measured by turbidity observations; mathematical analysis of these observations revealed that, within an error of ± 6 per cent., yeast grows according to a simple relationship which is known as the logistic. The logistic curve pictures yeast growth in the following way: Initially, when a small amount of yeast is seeded into afresh nutrient medium it grows freely according to the so‐called compound interest law; gradually, however, its growth rate falls off as the result of chemical changes in the medium, until eventually growth entirely ceases. The logistic representation of yeast growth has been shown to be applicable over a wide range of experimental conditions. The comparatively small deviations from the strict logistic relationship which occur in actual experiment are probably due to autolysis and to acclimatisation of the yeast to its environment.