ABSTRACT
Growth rate is well documented as determining crucial cell properties whether in suspension or as a biofilm. Biofilm growth per se brings about physiological changes independent of growth rate. Numerous cell properties change over the course of the division cycle and contribute to heterogeneity during logarithmic growth. The use of synchronous culture at specific stages is an underdeveloped technique for enhancing reproducibility. The origins of any particular culture lie in biological evolution. A "fresh" culture from, say, a culture collection may well have subcultures to any particular experiment or procedure. Post-growth handling procedures such as centrifugation, vortexing and, indeed, any change, especially if rapid, such as resuspending in a liquid of different composition, pH, osmolarity, or temperature to the original growth conditions can cause changes to a culture. The presence of small, relatively dormant cells, often after slow growth or starvation, may especially contribute to lack of reproducibility of a heterogenous culture.
