One reason food is refrigerated to control microbial growth is because irreversible cell damage is more likely to occur at low rather than high temperatures
Heterotrophic bacteria will run out of organic growth substrates in batch cultures but chemostats can provide constant nutrient source for them to grow
By using a stain targeting living cells only, microscopy would be a better approach to enumerate the number of living cells in a soil sample compared to viability counts of serially diluted soil
For most purposes of studying bacterial isolates, viable counting usually gives accurate information about the number of active cells present in a culture volume
When viable cell concentrations are too high to count on an agar medium, it is most common to use larger sized plates to increase the surface area for counting the colonies