Ghassem Amoabediny, Mahdi Pesaran Haji Abbas, Jochen Büchs:
Determination of CO2 sensitivity of micro-organisms in shaken bioreactors. II. Novel online monitoring method
Biotechnology and Applied Biochemistry, 2010, 57(4), 167-175
In the present study, a new online monitoring method for the determination of the CO2 sensitivity of micro-organisms, based on the values of the respiration factors [OTR (oxygen transfer rate) and CTR (carbon dioxide transfer rate)], obtained by using the RAMOS (respiratory activity monitoring system) device considering a variety of aeration rates in the measuring flask, is investigated. Based on the data of the OTR, obtained by RAMOS under a variety of specific aeration rates, the proposed new method was developed as an online monitoring method for CO2 sensitivity of micro-organisms in shaken bioreactors. A maximum accumulated CO2 concentration of 12% was derived in applied methods, provided that the cultivation system is carried out under optimal conditions. Additionally, to predict these conditions, an unsteady-state gas transfer model in shaken bioreactors would be very advantageous. The data of OTR obtained using the RAMOS device were analysed and recalculated by a programme considering the calibration factor (Cf ). The major advantage of the new method is the possibility to determine the metabolic activity, regardless of manual sampling.
biomass, bioreactor, carbon dioxide, fermentation, ventilation flask, unsteady model.