Send to

Choose Destination
Biotechnol Prog. 2019 Sep 12:e2911. doi: 10.1002/btpr.2911. [Epub ahead of print]

Scale-up of a type I secretion system in E. coli using a defined mineral medium.

Author information

AVT - Biochemical Engineering, RWTH Aachen University, Forckenbeckstr. 51, D-52074 Aachen, Germany and Bioeconomy Science Center (BioSC), Jülich, Germany.
Numaferm GmbH, Merowingerplatz 1a, Düsseldorf, Germany.
Institute of Biochemistry, Heinrich-Heine University, D-40225 Düsseldorf, Germany and Bioeconomy Science Center (BioSC), Jülich, Germany.


Secretion of heterologous proteins into the culture supernatant in laboratory strains of E. coli is possible by utilizing a type I secretion system (T1SS). One prominent example for a T1SS is based on the hemolysin A toxin. With this system, heterologous protein secretion has already been achieved. However, no cultivations in a defined mineral medium and in stirred tank bioreactors have been described in literature up to now, hampering the broad applicability of the system. In this study, a mineral medium was developed for cultivation under defined conditions. With this medium, the full potential and advantage of a secretion system in E. coli (low secretion of host proteins, no contamination with proteins from complex media compounds) can now be exploited. Additionally, quantification of the protein amount in the supernatant was demonstrated by application of the Bradford assay. In this work, host cell behavior was described in small scale by online monitoring of the oxygen transfer rate (OTR). Scalability was demonstrated by stirred tank fermentation yielding 540 mg/L HlyA1 in the supernatant. This work enhances the applicability of a protein secretion system in E. coli and paves the way for an industrial application. This article is protected by copyright. All rights reserved.


E. coli; metabolic burden; mineral medium; online monitoring; protein secretion; scale-up


Supplemental Content

Full text links

Icon for Wiley
Loading ...
Support Center