SDS-PAGE (A-C) and derived product amounts (D) of samples from the expression of 6 × His-MBP-RI in E. coli RV308/pibpfxsT7lucA/pCTUT7MBP-RI fed-batch and batch cultures. (A) Bioreactor process-1, (B) Bioreactor fed-batch process-2, (C) Bioreactor batch process. Lanes: 1 - total protein fraction 10 min before induction, 2 to 4 - soluble protein fraction (2), total protein fraction (3) and insoluble protein fraction (4), all 4 hours of induction. (D) Yield of soluble 6 × His-MBP-RI in mg per gram of cell dry weight [mg (g CDW)-1] in relation to the specific growth rate at the time of induction. Lane abbreviations: T - total, S - soluble, IN - insoluble protein fractions. Lanes marked with M: protein size marker PageRuler™ Protein Ladder Plus from Fermentas Ltd. (E) Detected ribonuclase inhibitor activities (in kilo units) in the cellular crude extracts, calculated for 1 gram of cell wet weight [kU (gCWW)-1] after bioreactor batch and fed-batch cultivation with 6 × His-MBP-RI protein production at 37°C in E. coli RV308/pibpfxsT7lucA/pCTUT7MBP-RI.
Šiurkus et al. Microbial Cell Factories 2010 9:35 doi:10.1186/1475-2859-9-35