Fed‐batch culture automated by uses of continuously measured cell concentration and culture volume

Abstract

An automated control method of fed-batch culture in which the nutrient feed rate was determined from continuously measured cell concentration and culture broth volume was developed. Theoretical background was elucidated, from which it was found that the method is unique in that it controls specific substrate consumption rate of the microorganism. The method was experimentally applied to the fed-batch cultures of recombinant Escherichia coli HB101. It was observed that the specific substrate feed rate affects not only the specific growth rate but also the growth yield. If some conditions are satisfied, this type of automated fed-batch culture can be applied widely to any microbial systems and seems especially useful when the culture medium is composed of natural complex nutrient(s) because their concentrations are very difficult to detect and control.

Monitoring of Saccharomyces cerevisiae in commercial bakers' yeast fermentation

“…Once the liquid level reaches the cell mass probe, the response of the probe reflects the growth of the yeast. After approximately [14][15][16] h of fermentation, the yeast is harvested. As the liquid level drops, the probe is no longer immersed in the yeast broth and the probe readings drop.…”

“…'~ Optical density based sensors offer the potential for in situ monitoring of yeast. 1 9 3 , 4 , C 8 , 10,12,14,15 One particular problem with the application of most optical sensors to bakers' yeast fermentations has been the confounding influence of increasing molasses solids and color during the fermentation due to the Biotechnology and Bioengineering, Vol. 46, Pp.…”

Robust artificial intelligence tool for automatic start-up of the supplementary medium feeding in recombinant E. coli cultivations

“…The sampling period was 10 s. Analyzing these data, a group of human experts consensually determined the best moment to start the supply of supplementary medium (the qualitative reasoning behind this choice may be found, for instance, in Yamane et al [40]). …”

Growth characteristics ofEscherichia coliHB101[pGEc47] on defined medium

“…Escherichia coli HB101 is a K12-type strain auxotrophic for leucine, proline, and thiamine (Gschaedler and Boudrant, 1994;Favre-Bulle et al, 1993;Yamane et al, 1992;Seo and Bailey, 1985). The recombinant E. coli HB101[pGEc47] contains a plasmid with the alkane oxidation genes from Pseudomonas oleovorans for the conversion of alkanes to the respective alkanoic acids (Favre-Bulle et al, 1991).…”