Formate accumulation due to DNA release in aerobic cultivations of Escherichia coli
2002 (English)In: Biotechnology and Bioengineering, ISSN 0006-3592, E-ISSN 1097-0290, Vol. 77, no 3, 324-328 p.Article in journal (Refereed) Published
Three different aerobic fed-batch processes of Escherichia coli were studied, two for the production of a recombinant protein and one process with a wild-type E. coli strain. In all three processes, an accumulation of formate could be observed in the latter part of the process. Analysis of the concentration of DNA in the medium revealed that the release of DNA coincided with the accumulation of formate. It was found that increasing concentrations of DNA correlated in almost linearly increasing concentrations of formate. Formate accumulation is caused by mixed acid fermentation, although no oxygen limitation was measured with the DO electrode. It is proposed that extracellular DNA restrained mass transfer between the bulk medium and the cell. To investigate if the DNA accumulation caused formate production, DNA was removed by continuous feeding of a DNA binding polymer to the medium. The addition of the polymer decreased the content of free DNA in the broth and the formate was reassimilated. Furthermore, additional DNA early in the process resulted in early formate accumulation.
Place, publisher, year, edition, pages
2002. Vol. 77, no 3, 324-328 p.
Escherichia coli fed-batch, mixed acid fermentation, formate formation, DNA release, gradients, DNA flocculation, scale bioreactor, culture, performance
IdentifiersURN: urn:nbn:se:kth:diva-21275DOI: 10.1002/bit.1198ISI: 000173407200010OAI: oai:DiVA.org:kth-21275DiVA: diva2:339973
QC 201005252010-08-102010-08-10Bibliographically approved