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Measurement of heat evolution and correlation with oxygen consumption during microbial growth
Author(s) -
Cooney C. L.,
Wang D. I. C.,
Mateles R. I.
Publication year - 1969
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/bit.260110302
Subject(s) - fermentation , growth rate , chemistry , yeast , bacterial growth , microorganism , oxygen , bacteria , thermodynamics , food science , biochemistry , biology , mathematics , physics , geometry , organic chemistry , genetics
A procedure for measuring the rate of heat production from a fermentation has been developed. The method is based on measuring the rate of temperature rise of the fermentation broth resulting from metabolism, when the temperature controller is turned off. The heat accumulation measured in this manner is then corrected for heat losses and gains. A sensitive thermistor is used to follow the temperature rise with time. This procedure is shown to be as accurate as previous methods but much simpler in execution. Using this technique, the rate of heat production during metabolism was found to correlate with the rate of oxygen consumption. Experiments were performed using bacteria ( E. coli and B. subtilis ), a yeast ( C. intermedia ), and a mold ( A. niger ). The substrates investigated included glucose, molasses, and soy bean meal. The proportionality constant for the correlation is independent of the growth rate, slightly dependent on the substrate, and possibly dependent On the type of organism growth. This correlation has considerable potential for predicting heat evolution from the metabolism of microorganisms on simple or complex substrates and providing quantitative parameters necessary for heat removal calculations.