  We propose an adaptive control law that allows one to identify unstable
steady states of the open-loop system in the single-species chemostat model
without the knowledge of the growth function. We then show how one can use this
control law to trace out (reconstruct) the whole graph of the growth function.
The process of tracing out the graph can be performed either continuously or
step-wise. We present and compare both approaches. Even in the case of two
species in competition, which is not directly accessible with our approach due
to lack of controllability, feedback control improves identifiability of the
non-dominant growth rate.
