Abstract: An apparatus for detecting the presence of a microorganism in a microbial sample includes a first enclosable chamber for holding a first portion of a microbial sample. The first enclosable chamber holds the first portion of the microbial sample in a manner that allows a gaseous region to be formed therein thereby defining an interface between the gaseous region and the first portion. The apparatus of this embodiment further includes a first metabolic compound monitor in communication with the gaseous region. The first metabolic compound monitor provides a signal functionally dependent on metabolic compound concentration in the gaseous region wherein the signal allows identification of a metabolic compound rich state and metabolic compound depleted state such that at some point during a predetermined period of time a transition between the metabolic compound rich state and the metabolic compound depleted state occurs. The method executed by the apparatus is also provided.