Image analysis as a tool for viability and recombinant protein production assessment during E. coli fermentations

Abstract

The development of monitoring methods for physiological state assessment during recombinant fermentation processes has been encouraged by the need to evaluate the influence of processing conditions in recombinant protein production. In this work, microscopy and image analysis techniques were used for the quantification of viability and protein production in two recombinant E. coli batch fermentations. Images obtained from light microscopy with phase contrast were used to assess the total number of cells in a given sample and, from epifluorescence microscopy, both producing and dead cells were counted using two different filters. This methodology allowed the extraction of information related to cell viability and recombinant protein production. This information, combined with standard fermentation data, allowed the derivation of interesting hypothesis that can be used afterwards for experimental design and further validation. Additionally, the ratios calculated in this work can be complemented with other parameters that can be extracted from image analysis.