Fed-batch production of recombinant fuculose-1-phosphate aldolase in E. coli

Escherichia coli strain XL1 blue (pTrcfuc) was used to overexpress fuculose-1-phosphate aldolase (Fuc-1-phosphate) in a fed-batch bioreactor operating at constant specific growth rate, 0.1 h−1. Maximum dry cell weight concentration in the fermentor was 45 g dm−3, over this biomass concentration oxygen became limiting. Once the recombinant strain behaviour was characterised under fixed growth conditions, optimal induction conditions to maximise the recombinant protein productivity in the system was studied. Time after induction to achieve maximum specific activity was around 11 h. Best results obtained were: specific activity of 1100 AU g−1 DCW, enzyme concentration of 47,000 AU dm−3 (around 3 g dm−3) and global volumetric productivity of 1200 AU dm−3 h−1.