Secondary metabolism occurs in bacteria during the stationary phase of growth and is concomitant with a switch in energy and carbon flux away from biomass production toward the production of small, bioactive molecules (secondary metabolites)

Microbial physiology is the study of how the microbial cell functions biochemically. Includes the study of microbial growth, microbial metabolism and microbial cell structure.

Molecular biology is the field of science concerned with studying the chemical structures and processes of biological phenomena involving molecules. This provides new insights into the nature of genes and proteins and the relationship between them.