Microbial Growth Control

Apuntes

General Microbiology Lab Vu, Nam – August 2026 Page 30 of 81 ❖ Controlling Microbial Growth Growth can be defined as an increase in size or in the number of something. Our focus in this section is on ways to control the number of microbial cells and thus their population. Bacteria reproduce through an asexual process called binary fission, where one cell splits into two cells, each of those cells also split into two cells, thereby doubling the population with each instance. The generation time, also called the doubling time, is highly variable and species-dependent, which may be as short as several minutes or as long as a couple of weeks! Understanding the growth characteristics of a population helps us in its control. The growth curve is a graphical representation of the change in a population over time and has four main phases. This table describes the four phases of a generalized bacterial population in the lab setting (Figure 5.1). Phase Description Lag Period of adjustment immediately after being introduced to a new environment. DNA replication and protein synthesis are taking place, but the rate of binary fission is low and there is no significant change to population. Expone...