Fig. 1

Schematic representation of successive phases controlling protein production and of the corresponding involved key factors, as inferred by the data reported in recent publications For each relevant step, the most promising approaches for improving yields and functionality of recombinant proteins that have been reported in the articles discussed in this review are listed. Numbers in brackets correspond to references. Of course, these options do not embrace the complete array of possibilities but rather mirror the reality described in the cited papers that preferentially focused on some topics, whereas others, such as the use of different promoters, the codon optimization, the overexpression of molecular chaperones or the addition of osmolytes, just to name a few, apparently were not investigated as actively in the last few years. This does not mean that such factors are less relevant for successful recombinant protein production, only that they were not further optimized lately