The unique description of the dependences of the specific consumption coefficients on the process state known from the literature is an important prerequisite to the further increase of the intensity and efficiency of the process for the industrial protein synthesis. Suitable measuring quantities for it are entropy production, an important quantity of thermodynamics of irreversible processes, and differential heat flow which can be measured by microcalorimetry. The description of the dependences of consumption coefficients by thermodynamics of irreversible processes allows an ingenious statement of calorimetric measurements of the fermentation process to confirm and to make precise the knowledge deduced from thermodynamics. Thermodynamical considerations and calorimetric measurements are used to describe the dependences of consumption coefficients on substrate concentration, nature of limitation, and periodical perturbations of the process.

Fermentation kinetic, thermokinetic and morphological investigations of biological carbonsource conversions into microbial biomass and other reaction products can be used for improving the efficiency of biotechnical processes. In this way biorhythmic processes on a macroscopic scale could be found in transitional stages of microorganism cultivation. These biorhythmic processes can be explained by the occurence of different cell states in the cell cycle. I n order to characterize these cell states synchronized microorganism growth was investigated with the aid of the phased culture method. Two states could be observed in the case of yeast growth: the single ccll state and the budding cell state. The duration and efficiency of the single cell state is dependent on the growth limitation and the carbon substrate feeding. Thus the reduction of carbon substrate feeding in states of synchronized populations which are characterized by a high percentage of single cells and by energy metabolite production which, in turn, is influenced by carbon substrate concentration can cause increased material and energetic efficiencies of biological carbon-source conversions.

A nonisothermal flow cdorimeter operating directly in the fermenter was used for heat flow meitsurements of aerobic microbial growth processes with high biomass productivities. The measuring nrrangement.makes i t possible to describe transitional stages of aerobic yeast cell growth by thc ratio of heat production to oxygen consumption (oxy-caloric coefficient). The oxy-caloric coefficient was not constant under the described conditions. The results refer to the existence of an additional encrgy-delivering mechanism in microbial systems with aerobic carbon source utilization. The mechanism c:tn involve polyphosphnte bond division coupled to biomass synthesis. ZusamnicnfassungEin im Fermentor arbeitendes anisothermes DurchfluDkalorimeter wurde zu WiirmefluBiuessungen an seroben mikrobiellen Wachstumsprozessen bei hohen Biomassebildungsraten angeaendet. Die MeBanordnung erlaubt die Beschreibung des ubergangsverhaltens aerober Wachstumsvorgiinge durch die Ermittlung des Verhiiltnisses von Warmeproduktion und Sauerstoffverbrauch (oxy-kalorischer Koeffizient). Dieser Koeffizient ist unter den beschriebenen Bedingungen keine Konstante. Die experimentellen Ergebnisse deuten auf die Existenz eines zusiitzlichen energieliefernden Mechanismus in mikrobiellen Systemen, in denen die Kohlenstoff-nnd Energiequelle oxydntiv abgebaut wird. Dieser Mechanismus kann eine enge Kopplung der Spaltung von Polyphosphatbindungen und der Biomassesynthese enthnlten.

The influence of perturbations on continuous yeast cell cultivations on hydrocarbons of crude oil is described.Due to such perturbations the fermentation system leaves its steady state, passes through transitional stages and reaches a new steady state. In the transitional stages a damped oscillation of biomass concentration, percentage of budding cells, oxygen consumption rate, and heat flow is observed. These results can be explained by partial synchronization of yeast cell functions in microorganism populations. I n phases of partial synchronization the cell cycle of a single cell is reflected by the behaviour of the microorganism population. The adaptationof the carbon substrate feeding rate to the state of partially synchronized microorganism population makes possible lower specific substrate consumption in biomass production.

The experimental technique for measurement of microbial culture heat evolution directly in fermenter has been described and its correctness analysed. Heat-to-oxygen ratio, Qo, of synchronized yeast culture in the absence of fermentative metabolism has been found to be practically independent of a cell cycle phase and close to the theoretical constant predicted by the mass-energy balance theory. The collection of literature data on the heat-to-oxygen ratio is given. Energetic properties of cell biomass are discussed on the bask of the obtained and the surveyed values of Q0.