AbstractFed‐batch cultures of recombinant microorganisms have attracted attention as they can separate cell growth stage from cloned‐gene expression phase during fermentations. In this work, the effect of different glucose feeding strategies on cell growth and cloned gene expression was studied during aerobic fed‐batch fermentations of recombinant yeast, containing the plasmid pRB58. The plasmid contains the yeast SUC2 gene, which codes for the enzyme invertase. Some feeding policies resulted in a constant glucose concentration inside the fermentor, while others deliberately introduced a cyclic variation. The cell mass yield was found to be higher at low glucose concentrations, thus indicating a shift to the more energy‐efficient respiratory pathway. The SUC2 gene expression was derepressed at glucose levels below 2 g/L. The response of specific invertase activity to changes in the medium glucose concentration was found to be almost immediate.