A New Tool for the Quantification of Microorganism Interaction Dynamics

Abstract

A two-reservoir, membrane bioreactor for carrying out studies of mixed population dynamics in batch fermentation is presented. Mixing requirements and design aspects for the validity of the approach are presented and discussed. Equations describing mixing times between the reservoirs are given and compared to the experimental results. The validity of the approach is demonstrated by the study of several types of situations in the bioreactor. The main validation consists of the comparison between the results obtained in an actual mixed culture and the results obtained by keeping the strains separated. Finally, this new tool is used to study the interaction kinetics between two oenological bacteria. These experiments in liquid media help to determine the seeding conditions for a chosen strain to overgrow another strain through a quantification of the interaction dynamics.