Microbial Growth

01Microbial Growth

Population growth

This section covers how the growth of a microorganism population in broth culture can be investigated over time.

Growing microorganisms in culture

The growth of populations of microorganisms such as bacteria or yeast can be investigated by growing them in a nutrient broth culture.

After the broth is inoculated with the microorganisms, the population increases as the cells reproduce. Measurements taken at fixed time intervals can be used to follow this change in population size.

Microbial populations can increase rapidly, producing very large numbers of cells within a relatively short period. This makes methods that estimate population size particularly useful.

Following growth over time

  1. Grow the microorganism in a broth culture.
  2. Begin measurements after the broth has been inoculated.
  3. Take measurements at fixed time intervals.
  4. Use the measurements to estimate how the population changes.
  5. Plot the results to produce a population growth curve.

The changing population can be followed indirectly by measuring the turbidity of the culture.

Create a free account to continue

Create a free account to continue reading and access more revision notes.