Microbiology and Microbiological Techniques
Introduction
Microbiology is the study of super small organisms, like bacteria and viruses. These tiny life
forms are everywhere, and they're super important to our health and the environment. By
learning about them, we can find new ways to fight diseases and use good microbes to help
us with stuff like making food and cleaning up pollution (Microbiology Society, 2024).
Several factors influence the growth of bacteria and fungi, one of which is the enzyme
synthesis process that occurs when these microorganisms are introduced into a growth
media. Initially, they must synthesise enzymes in order to successfully use the nutrients in
the medium. This synthesis process takes time because genes must be activated and then
transcribed to mRNA before the genetic information can be translated into functional
proteins like enzymes. This advanced process demonstrates the complexities of microbial
growth, and the critical function enzymes play in nutrient consumption for bacterial and
fungal growth in a particular environment (Canvas, Class Notes, 2024).
(Canvas, Class Notes, 2024).
In the life cycle of microorganisms, we see four distinct growth phases in a typical bacterial
culture. During the lag phase, bacteria are gearing up for the next stage of growth, adapting
to their new environment and not yet multiplying. Next comes the log phase, where
bacteria start to divide rapidly, leading to rapid growth. This is when they're most active and
vulnerable to antibiotics.
After the log phase, the stationary phase kicks in. Here, the growth rate slows down as
nutrients reduce and waste products build up, leading to a balance between cell division
and cell death. Finally, in the death phase, the number of dying cells overtakes the number
of new cells being formed, leading to a decline in the population (Canvas, Class Notes,
2024).
, Temperature
Microorganism growth and development are significantly influenced by temperature.
Temperatures between 20°C and 45°C are ideal for the majority of mesophiles, which are
bacteria and fungus. It is in this temperature range that these creatures develop to their
best. While some psychrophilic bacteria can survive in temperatures as low as -20°C to 10°C,
they are more suited to colder climates. As a result of this, thermophiles are specialised
microorganisms that grow best in temperatures between 41°C and 122°C. They live in high-
temperature habitats (Canvas, Class Notes, 2024).
(Canvas, Class Notes, 2024)
pH
The activity of the enzymes that microbes use is significantly influenced by the pH of the
extracellular environment. Enzymes have a pH range in which they function best; any pH
variation can cause an enzyme's activity to slow down. Many enzymes can become
denatured by extremely high or low pH levels, which results in their active sites no longer
matching with the molecules of the substrate. Therefore, metabolic reactions stop at these
pH extremes, which inhibits the growth and division of microbes (Canvas, Class Notes,
2024).
(Canvas, Class Notes, 2024).
Light
In order for some species, such as some photosynthetic bacteria and protists, to produce
energy, light is essential. For these organisms, light is a vital source of energy for their
Introduction
Microbiology is the study of super small organisms, like bacteria and viruses. These tiny life
forms are everywhere, and they're super important to our health and the environment. By
learning about them, we can find new ways to fight diseases and use good microbes to help
us with stuff like making food and cleaning up pollution (Microbiology Society, 2024).
Several factors influence the growth of bacteria and fungi, one of which is the enzyme
synthesis process that occurs when these microorganisms are introduced into a growth
media. Initially, they must synthesise enzymes in order to successfully use the nutrients in
the medium. This synthesis process takes time because genes must be activated and then
transcribed to mRNA before the genetic information can be translated into functional
proteins like enzymes. This advanced process demonstrates the complexities of microbial
growth, and the critical function enzymes play in nutrient consumption for bacterial and
fungal growth in a particular environment (Canvas, Class Notes, 2024).
(Canvas, Class Notes, 2024).
In the life cycle of microorganisms, we see four distinct growth phases in a typical bacterial
culture. During the lag phase, bacteria are gearing up for the next stage of growth, adapting
to their new environment and not yet multiplying. Next comes the log phase, where
bacteria start to divide rapidly, leading to rapid growth. This is when they're most active and
vulnerable to antibiotics.
After the log phase, the stationary phase kicks in. Here, the growth rate slows down as
nutrients reduce and waste products build up, leading to a balance between cell division
and cell death. Finally, in the death phase, the number of dying cells overtakes the number
of new cells being formed, leading to a decline in the population (Canvas, Class Notes,
2024).
, Temperature
Microorganism growth and development are significantly influenced by temperature.
Temperatures between 20°C and 45°C are ideal for the majority of mesophiles, which are
bacteria and fungus. It is in this temperature range that these creatures develop to their
best. While some psychrophilic bacteria can survive in temperatures as low as -20°C to 10°C,
they are more suited to colder climates. As a result of this, thermophiles are specialised
microorganisms that grow best in temperatures between 41°C and 122°C. They live in high-
temperature habitats (Canvas, Class Notes, 2024).
(Canvas, Class Notes, 2024)
pH
The activity of the enzymes that microbes use is significantly influenced by the pH of the
extracellular environment. Enzymes have a pH range in which they function best; any pH
variation can cause an enzyme's activity to slow down. Many enzymes can become
denatured by extremely high or low pH levels, which results in their active sites no longer
matching with the molecules of the substrate. Therefore, metabolic reactions stop at these
pH extremes, which inhibits the growth and division of microbes (Canvas, Class Notes,
2024).
(Canvas, Class Notes, 2024).
Light
In order for some species, such as some photosynthetic bacteria and protists, to produce
energy, light is essential. For these organisms, light is a vital source of energy for their
