Design and application of software sensors for monitoring of fed-batch cultivations containing recombinant Escherichia coli

Abstract:

Bioprocesses are industrial processes that use living cells to produce desired products. These processes are complex and require advanced monitoring and control in order to reach their highest potential. Software sensors are a potent tool for real time monitoring and control of bioprocesses. In this project, three novel software sensors were designed and tested in three fed-batch cultivations containing recombinant Escherichia coli producing green fluorescence protein (GFP). Special attention was given to the sensors for reacting to any stress triggered when production of the recombinant protein was initiated by an inducer molecule.

The sensors calculated the oxygen consumption per substrate, carbon emission per substrate and the sum of the specific growth rates of various acids. Their mathematical algorithms were derived from already existing software sensors and programmed on to computer software designed for monitoring and control.

The results showed that all three sensors gave stable signals as expected. Unfortunately they did not provide any useful information regarding the recombinant protein expression in this particular study. Complications such as measurement errors and incorrect system configurations also created difficulties. It is clear however, that the sensors work well and should be highly considered for further studies.