Fig. 3

Extracellular protein production in bioreactors under fed-batch mode. a Comparison between RUT-C30 and the engineered Br_TrR03 strain in bioreactor cultivations with an inducer-rich medium. b Extracellular protein production by Br_TrR03 during bioreactor cultivations with a molasses-based batch medium supplemented with different nitrogen sources: ammonium sulfate only, yeast extract, YEPD-grown yeast (YEPD yeast) and molasses-grown yeast (MG-yeast). The feed comprised sugarcane molasses or acid-inverted molasses (inv. molasses). For comparison purposes, a fermentation with the strain Br_TrR02 using acid-inverted molasses and molasses-grown yeast is shown. Results are expressed as mean ± SD (n = 3)