A method of evaluating the intensity of spatial mixing of the microorganisms in the bioreactors, continuous

The research work offers a new evaluation technique of longitudinal mixing intensity of biotechnological suspension in fixed reactors by counting the proportion of microorganisms that differ by the stay period in any certain reactor volume. To estimate the mixture level of microorganisms of different ages in a vessel volume of interest is important to both biotechnologist and equipment engineers to form the structural-functional model of two-phase suspension flow (including microorganisms), to control the flow and to define the main fluid dynamics and technological parameters of the implementing process. It has been known that when the microorganisms of too different age coexist in a unit volume of the production substrate, the biochemical process of directed mass transfer goes ineffective. Since the metabolic processes of microorganisms run with great speed, the change of their functional age character can be correlated with the residence time of the cells in the system. To make the principal decisions while constructing new equipment (or improving the existing one) with the aim of realizing the flow model which is close to piston flow, it is necessary to have the correct method of calculating the proportion of coexisting microorganisms with different stay periods in the bioreagents flow volume of interest. This research work offers a probability-theoretical approach to making the mathematical model of the two-phase fluid diffusion flux, that allows to calculate the proportion of coexisting microorganisms with different stay periods in the in the arbitrarily given vessel volume. The method is based on the mathematical apparatus of the Markovian diffusion process, which is characterized by mathematical simplicity and physical clearness. Thus the obtained results allow us to assume the fluid-flow state of the ‘production substrate–microorganisms’ system, and, building upon it, to predict the efficiency of biochemical processes realized in flow-through apparatus.