Biofilms are immobilized microorganisms on a surface. The so-called immobilization (fixation) of microoganisms provides a chance for enhancement of effiency and for simplification of operation for bioprocesses. Biofilms are deployed in biotechnology for example, for the production of amino acids and vitamins. The formation of biofilms in a bioreactor depends on many factors, including the interaction between the immobilization body and the microorganisms on the supply of the microorganisms. Biochemical engineering uses different reactor types to satisfy the requirement of microorganisms, in the consideration of mixing, subtrate feed and oxygen need. In multi-phase reactors, the components of special reaction are available in at least two phases; gas phase and liquid phase. For most applications it is essential to contact the phases intensely to get an effectively oxygen transfer, and to gain a high and profitable reaction rate. The Aim of this dissertation is, to gain an interpretation of a newly designed gas-liquid-reactor with ceramic monoliths for the oxygen supply of aerobic microorganisms. The focus of this work is the volumetric oxygen transfer coefficient kLa, which desribes the intensity of oxygen transfer between gas and liquid phase. The reactor interpretation results are primarily based on experimental data, which include the variation of gas and liquid flow rate, bubble size and dimension of the monoliths. The findings of all experimental series conclude that smaller bubbles bring a higher transfer coefficient independently of all other parameters. Furthermore the kLa value increases with increasing gas flow rate in all tests. To get a highervolumetric oxygen transfer in the reactor, in consideration of volume specific energy transfer it can be suggested to raise the length of the monoliths. The regression analysis ensures an interpolation and a limited extrapolation. According to all experiments and considering an optimal operating point of the new designed gas-liquid-reactor can be resumed in dependency of the volume specific energy transfer
