Indirect monitoring of protein A biosynthesis in E.coli using potentiometric multisensor system

[Display omitted] •E.coli fermentation media samples were analyzed with potentiometric e-tongue.•Samples were analyzed with ELISA to quantify the protein A content in the cells.•PLS allows for quantitative assessment of protein A production from sensors response. Fermentation process monitoring is a very important factor for controlled protein biosynthesis in industry. Currently the only method to determine protein concentration in cultivation broth is ELISA (enzyme-linked immunosorbent assay). Having high sensitivity and specificity, ELISA takes several hours to run, which is not suitable for express monitoring. A recent progress in multisensor systems for chemical analysis (electronic tongues) shows a good promise for application of such systems in fermentation-related tasks. The objective of this work was feasibility study of potentiometric multisensor system as an instrument for indirect assessment of protein production through chemical measurements in a cultivation medium. The samples taken from nine fermentation processes intended for production of recombinant protein A of Staphylococcus aureus (SpA) in Escherichia coli were analyzed with the electronic tongue system comprised of 14 potentiometric sensors. The system was able to monitor the global changes in the media composition as the fermentation progressed. By means of PLS regression it was possible to relate the responses of the sensors with the data on protein production from ELISA. The system was able to predict the content of SpA based on potentiometric measurements with accuracy suitable for monitoring purposes. It appears to be attractive alternative for ELISA in fermentation control tasks.