大象传媒

Treating, curing and preventing disease - AQABacterial growth in cultures

Some diseases can be treated with antibiotics. Vaccinations allow protection against specific diseases, but the level of protection depends on the amount of people vaccinated.

Part of Biology (Single Science)Infection and response

Bacterial growth in cultures

Bacterial growth

can replicate approximately every 20 minutes by , which is a simple form of . This level of replication will depend on the availability of nutrients and other suitable conditions such as temperature.

Diagram of how quickly bacteria can replicate within an hour

There are many ways to culture bacteria, and these include:

  • nutrient broth solution
  • colonies on an agar plate

Nutrient broth solution or culture medium, allows a liquid or gel to provide all the nutrients needed for bacteria to grow successfully. These must include: carbohydrates for energy, nitrogen for , plus other minerals.

are created by pouring hot molten agar into sterile , which are then allowed to set. Bacteria can be spread onto the plates, and allowed to form of the specific bacterium.

Uncontaminated cultures

If a specific bacterium is going to be or grown, other contaminating bacteria would compete for nutrients in the broth or agar. Plus some bacteria could be harmful (such as ) and would complicate the results of experiments when testing the efficiency of antibiotics or other anti-microbial compounds.

Bacteria can replicate approximately every 20 minutes by binary fission, which is a simple form of cell division. This level of replication will depend on the availability of nutrients.
Figure caption,
Each labelled bacterium represents a microorganism that can be cultured in an agar plate