Microbial nutritional classification organizes microorganisms according to their energy source (phototrophs versus chemotrophs), electron/hydrogen donor (lithotrophs versus organotrophs), and carbon source (autotrophs versus heterotrophs), with these axes combining into composite categories such as photoautotroph and chemoheterotroph that describe how an organism obtains energy, reducing power, and biomass-building carbon. The bacterial growth curve is the standard model of population dynamics for a microbial culture in a closed (batch) system, describing the change in viable cell number over time as it passes through characteristic phases determined by resource availability, metabolic adaptation, and waste accumulation. Both frameworks belong to microbiology's treatment of microbial physiology and population biology, providing the vocabulary used to characterize how microorganisms acquire resources and how their populations behave under defined culture conditions.
Microbial nutritional classification organizes microorganisms according to their energy source (phototrophs versus chemotrophs), electron/hydrogen donor (lithotrophs versus organotrophs), and carbon …