ISSN:
0006-3592
Keywords:
Chemistry
;
Biochemistry and Biotechnology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
The alcoholic fermentation of grape juice by a wine yeast was studied batchwise at pH 3.6 and 4.05 to develop kinetic equations relating cell concentration, N, to product concentration, P. In the exponential growth phase \documentclass{article}\pagestyle{empty}\begin{document}$$ dP/dt + BP = A{\rm ln}N/\mu - C $$\end{document} where A, B, and C are constants, and μ is the specific growth rate. In the stationary phase, where the cell population is constant, \documentclass{article}\pagestyle{empty}\begin{document}$$ dP/dt = B(P_m - P) $$\end{document} was found to apply. This equation, which incorporates a stoichiometric constant, Pm, predicted correctly the operation of a continuous fermentor at pH 3.6 and at 4.05. To study more fully the effect of alcohol concentration on yeast growth, a continuous fermentor was used in which the grape juice feed was supplemented with pure alcohol. At pH 3.6 the specific growth rate varied as, \documentclass{article}\pagestyle{empty}\begin{document}$$ ({\rm 1}/N)(dN/dt) = \mu _{{\rm max}} [{\rm 1} - 0.235(P - 2.6)] $$\end{document} There was no growth inhibition below an alcohol concentration of 2.6 g./100 cc., but inhibition was complete above 6.85 g./100 cc. This is a modified form of the relation suggested by Hinshelwood.1 The data suggest that growth in batch culture was limited not only by alcohol but also by some other factor, probably a nutritional deficiency.
Additional Material:
7 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/bit.260090312
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