This property appears very useful if one wishes an overall measure of the numbers of bacteria based on time. On the other hand, for monitoring in vivo experiments fluorescent proteins (such as GFP), the fluorescence from flavins secreted into the culture medium will severely reduce the dynamic range of detection of the GFP. These flavins which emit in the same spectral range as GFP accumulate in the culture medium and make them dependent on the "history" of the culture.
Ultimately, a new "spectral" method of separating the flavin fluorescence from that of GFP is tested. This method allows the GFP signal to be used quantitatively in dynamical gene expression experiments.
The article has appeared in Physical Biology.