11 - Bacterial Growth, Culturability and Viability

Abstract

Bacterial growth involves the accumulation of biomass and may include genomic replication, cell division and an increase in the number of propagules of the organism concerned. For most bacteria, it is generally held that, after division, a newly formed cell placed in an environment favorable to growth doubles its mass and then divide to form two equal sized progeny by binary fission. The studies on carefully defined broth cultures remain the principal reliable source of information about the molecular basis of bacterial growth. A detailed analysis of the energetics and stoichiometry of bacterial growth has been made possible by analyzing bacterial populations growing at constant rates in chemostat or turbidostat cultures. The study reviews the arbitrary selection of genes whose expression has been related to growth in various ways. Determinations of viability have played a central role in bacteriology. In medical microbiology, this process is primarily concerned with measuring the effects of antimicrobial agents, sterilization and disinfection regimens, and with immune effector mechanisms. Established precedent indicates that a viable entity has the capacity to persist into the future and to carry out the functions with which it is normally associated.