Competition in the unstirred chemostat with periodic input and washout

The model of an unstirred chemostat is generalized to that of a chemostat w ith time-dependent input/washout rates. The novelty of the new model is tha t time periodicity appears in the boundary conditions. The asymptotic dynam ics of the competition between two microbial populations is determined in t erms of the corresponding period map, which is shown to preserve the standa rd competitive ordering. It is shown that the dynamics of competition is si milar to that of a chemostat with constant boundary conditions. Simple crit eria for coexistence versus competitive exclusion are presented.