Über den Einfluß von Zuckerzusätzen auf die Atmungsgeschwindigkeit von Hefesuspensionen

Damaschke, K.; Lorenz, Rüdiger; Tödt, F.

doi:10.1515/znb-1957-0510

Cited by 3 publications

(1 citation statement)

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“…from the endogenous value to the maximum, remained high until the substrate was exhausted, aiid then decreased rapidly with diminishing rate to the endogenous value again. Specific uptake rate, Q, was 4 The rapid changes of Q can be used to keep C, a t the desired value and thereby to adjust very simply the oxygen-uptake rate, Qx, to the absorption rate K,a(C -C,). All that is needed t o control Q is to stop or coritinue the feeding of substrate in the region where Q is dependent on substrate conceritratiori; it is a t 0-160 It is evident from the graph that one cannot achieve a change in Q beyond a certain value of S , corresponding to a maximum value of Q, Qmax, determined by the composition of the medium and by the properties of the microbe.…”

Section: Theory and Resultsmentioning

confidence: 99%

Oxygen‐absorption rate‐controlled feeding of substrate into aerobic microbial cultures

Hospodka

1966

Biotech & Bioengineering

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SummaryA system of automatic control of substrate inflow into an aerated culture of microorganisms which depend on oxygen-absorption rate (OAR) has been devised and tested. As the control variable, dissolved oxygen concentration (DOC), which shows the equilibrium between OAR and oxygen-uptake rate in the microbial culture, was chosen. If the equilibrium is disturbed by changes in OAR, then the oxygen-uptake rate is changed by substrate limitation. The DOC is measured by means of a Clark-type polarographic electrode, and the signal is used to actuate the substrate inflow valve or pump. The oxygen-uptake rate changes of microorganisms, after the addition or exhaustion of substrate in the medium, are so rapid that they can be used for this type of control.Fundamental equations were derived and graphical solutions for the control system parameters were suggested for the steady-state relations between DOC, oxygen-uptake rate, specific growth rate, substrate concentration, KLU, and conrentration of microorganisms. The system is stable in the entire range of the uptake rates up to nearly the maximum attainable in unlimited substrate conditions, and can be operated in batch feed or continuous flow modifications. It was experimentally tested with the yeast Saccharomyces cerevisiae. The complete utilization of aeration-system capacity of the fermentor was achieved with high yeast yield arid no alcohol formation. The quality of the product was excellent.

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Section: Theory and Resultsmentioning

confidence: 99%

Oxygen‐absorption rate‐controlled feeding of substrate into aerobic microbial cultures

Hospodka

1966

Biotech & Bioengineering

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Regulatory aspects of bakers' yeast metabolism in aerobic fed‐batch cultures

Woehrer

Roehr

1981

Biotech & Bioengineering

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SummaryA highly instrumented computer-coupled bioreactor is used to investigate metabolic changes of Sncchnrornyces cerevisine in aerobic fed-batch systems which are generally applied in bakers' yeast manufacture. The four types of metabolism (oxidation of glucose, aerobic fermentation, oxidation of glucose and ethanol, and oxidation of ethanol) appearing in such systems are characterized by four significant fermentation parameters: respiratory quotient (RQ), glucose uptake rate (On). ethanol turnover rate (&OH), and growth yield on glucose (YE). Below the critical glucose concentration glucose and ethanol are utilized simultaneously. The shift from aerobic fermentation to nondiauxic growth on glucose and ethanol is not only dependent on glucose concentration, but also on the precultivation of the cells. The uptake of ethanol is controlled by the glucose supply except in the case when ethanol is limiting; the oxygen uptake rate (Qo,), however, is unaffected by the ratio of Q, and QE~OH. Critical glucose concentration is not a constant value for a particular strain, but varies corresponding to the nutritional state of the cells.

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