Theoretische Bestimmung energetischer Wirkungsgrade der mikrobiellen Kohlenstoffsubstratwandlung und Vergleich mit experimentellen Werten an Phasenkulturen

Abstract

The phenomenological description of microbial substrate conversion is possible by connecting energy and material balance equations.The change of free enthalpy of microbial substrate conversion was determined on the basis of exact material balance equations. A simultaneous determination of heat production allowed to calculate the energetic efficiency of microbial growth processes. I n addition to this the change of free enthalpy by microbial substrate conversion was standardized by the free standard formation enthalpy of biomass. Both quantities were used for comparing microbial combustion of several substrates into biomass. Comparable with the concept of substrate combustion enthalpy standardized by the combustion enthalpy of biomass an optimal .strategy of mixing different substrates can be deduced from energy and material balance equaticns on the basis of theoretic consumption coefficients.Besides the energetic efficiency the binding state of the substrate is important in the search for optimal substrate mixing ratios. This could be shown by experimental work. Thus, the fermentation systems sucrose/yeast, paraffinlyeast, and sucrose/paraffin/yeast were studied using synchronous populations produced by the method of phased cultures. The investigations of real fermentation systems confirm the theoretical predictions on special conditions.

Cell cycle synchronization of Cupriavidus necator by continuous phasing measured via flow cytometry

“…A useful method for synchronizing cultures is the standard phasing technique, as previously described and used by Dawson (1972Dawson ( , 1985, Mueller and Dawson (1968), Thomas et al (1980a,b), Heinritz et al (1982), and Anagnostopoulos (1971) because it can induce high degrees of persistent, reproducible synchrony in cultures, using a simple periodic feeding strategy over several cycles. In this semi-continuous process half of the culture broth is discharged and replaced with exactly the same volume of fresh medium in a periodic manner.…”