Influence of Micromixing on Microorganisms and Products

The influence of mixing intensity as well as physical and chemical parameters on the cells of different microorganisms and the biosynthesis process is examined in this paper. Some reactions of cells effecting mixing intensity are described, such as retarded biomass growth, changes in aggregation and mutual arrangement of cells, morphological changes of cells and decreasing of biological activity, caused by an increased intensity of turbulence (turbohypobiosis). Several methods for investigating the local energy in reactors are compared. It is concluded that conventional methods of hydrodynamic analysis do not always allow valid results for the optimization of the mixing regime to be obtained; practically any system requires its own optimization to achieve the maximum yield. To prevent possible adverse effects of micromixing, while simultaneously employing the positive effects, the developers of a new biotechnological process should perform a whole range of experiments (for process optimization) varying temperature, pH and other factors, as well as aeration and mixing intensity simultaneously with medium composition.