Control of mixed microbial cultures via specific cell adhesion

A new method for manipulating the steady-state behavior of a mixed culture is introduced. The method makes use of differences in adherence properties between competing populations to maintain a desired population ratio. The very specific nature of some ligand-to-cell interactions allows precise manipulation of even closely related populations. The control method is illustrated by analysis and simulations of models of a competitive mixed culture and a culture of an unstable recombinant organism. In both cases, retention of the disadvantaged population via cell adhesion results in creation of a stable coexistence steady state over a range of operating conditions.