Biotechnology and Bioengineering, Vol.112, No.6, 1155-1164, 2015
Evaluation of a New Mist-chamber Bioreactor for Biotechnological Applications
In this article we describe the development, the characterization and the evaluation of a novel bioreactor type for the cultivation of different pro- and eukaryotic cell-systems: the mist-chamber bioreactor. This innovative bioreactor meets the demand of cultivation systems for shear stress sensitive cells with high requirements for gas supply. Within the mist-chamber bioreactor the cells are cultivated inside an aerosol of vaporized medium generated by ultrasonic vaporization. In contrast to many established bioreactor systems the mist-chamber bioreactor offers an environment with an excellent gas supply without any impeller or gas bubble induced shear stress. A mist-chamber bioreactor prototype has been manufactured and characterized during this work. In the technical and chemical characterization we evaluated the vaporization process, resulting in a vaporization performance of 32 mL/h at working conditions. On this basis we calculated a biomass of 1.4 g (S. cerevisiae, q(s) = 3.45 x 10-3 mol/g/h) and 3.4 g (Aspergillus niget; q(s),= 1.33 x 10-3 mol/g/h) where the growth rate becomes limited by transport processes. Additionally, we determined a homogenous cultivation area to a height of 3 cm giving a total volume of 0.45 L for the cultivation. Medium components were examined according to their stability during vaporization with the result that all components are stable for at least 5 days. After the technical characterization we demonstrated the feasibility to cultivate S. cerevisiae and E velupites in the mistchamber bioreactor. The results demonstrated that the mistchamber bioreactor is able to transport a sufficient amount of nutrients consistently to the cell samples and offers an excellent oxygen supply without any shear stress inducing aeration. Furthermore we successfully cultivated E velupites in a solid state cultivation in a long term experiment. The data indicate that the new bioreactor concept can contribute to improve various fermentations and cell culture processes depending on the cultured cell types. 0 2014 Wiley Periodicals, Inc.
Keywords:mist-chamber bioreactor;new bioreactor concept;ultrasonic vaporization;optimal oxygen supply