Eppendorf AG Bioprocess Center
Steffen Ostermann studied biology at the Heinrich-Heine University Duesseldorf, and finished in 2010 his Master thesis at the Forschungszentrum Jülich GmbH, Institute of Biotechnology headed by Prof. Wolfgang Wiechert, At the Institute of Bio- and Geo- sciences I: Biotechnology he performed from 2010 to 2013 metabolome- and fluxome analysis on Acetic Acid bacteria. Since the end of 2013 he works for the Eppendorf AG as Bioprocess Sales and Application Specialist.
Single-use bioreactor solutions have been successfully established in animal and human cell culture in the last years. Currently this technology is investigated for microbial applications. The following case study demonstrates that reproducible process control could be achieved using single-use bioreactors operated in parallel. E. coli K12 (DSM 498) was cultivated in a comprehensively equipped Eppendorf BioBLU® 1f Single-use Vessel. This rigid wall stirred-tank single-use bioreactor was specifically designed for microbial applications, and is equipped with two Rushton-type impellers, four baffles and liquid-free Peltier exhaust condensation. The magnetic coupled overhead drive safely operates up to 1600 rpm, ensuring kLa values of up to 4150 h-1. A 4-fold Eppendorf Parallel Bioreactor System with DASGIP® Control Software was used for precise process control. Starting with a working volume of 0.7 L the cultures were grown in PAN medium with an initial glucose concentration of 40 g/L. DO-based feeds started simultaneously in all 4 units 11.3 h (± 0.1 h) after inoculation. The temperature was set to 37 °C and the pH was adjusted to 6.8 using 25 % ammonia solution. The cultures were submerged aerated through integrated dip tubes with a constant rate of 42 sL/h (1 vvm). Dissolved Oxygen concentration was regulated to 30 % with the stirrer speed ranging from 600 rpm to 1600 rpm (tip speed of 1.34 m/s to 3.56 m/s). Oxygen transfer rates (OTR) were automatically calculated via an exhaust analysis module GA4. OTR values of up to 230 mmol/L/h were observed in the single-use bioreactors. Biomass was determined offline as cell wet weight and reached maximum values of 163 g/L. These results are comparable to results that have been obtained in glass bioreactors.