Culturing Microorganisms

How can bacteria multiply?

By simple cell division, binary fission.

How can the number of bacteria double every 20 minutes?

If they have enough nutrients and the optimum temperature.

What can bacteria be grown in?

A solution, nutrient broth, or as colonies on an agar gel plate.

What’s good aseptic technique important for?

For growing uncontaminated cultures of bacteria.

What’s the 1st step for culturing microorganisms?

Before culturing.

What’s good aseptic technique and safety before culturing?

Sterilise culture media and agar before use, wipe the workplace with disinfectant and pass an inoculating loop through a blue Bunsen flame and allow to cool slightly..

What’s the purpose for good aseptic techniques and safety before culturing?

Ensure no contamination in the media, kill any microorganisms on the surface and sterilise the inoculating loop.

What’s the 2nd step for culturing microorganisms?

Loosen the lid on the bacteria culture bottle and dip the inoculating loop in the culture.

What’s good aseptic technique and safety to loosen the lid and dip the inoculating loop in the culture?

Lift the lid as little as possible when dipping the inoculating loop.

What’s the purpose for good aseptic techniques and safety to loosen the lid and dip the inoculating loop in the culture?

Reduce the chance of contamination of the culture by microorganisms from the air.

What’s the 3rd step for culturing microorganisms?

Inoculate the agar gel plate by streaking the inoculating loop across the surafce of the agar.

What’s good aseptic technique and safety to inoculate the agar gel plate?

Lift one side of the agar gel plate’s lid as little as possible when inocluating the agar.

What’s the purpose for good aseptic techniques and safety to inoculate the agar gel plate?

Reduce the chance of contamination of the agar by microorganisms from the air.

What’s the 4th step for culturing microorganisms?

Tape the lid shut and place the inoculated agar gel plate in an incubator.

What’s good aseptic technique and safety to tape the lid shut and place the plate in an incubator?

Don’t create an airtight seal when taping the lid on, don’t incubate at temperatures higher than 25 and incubate plates with surface of the agar downwards.

What’s the purpose for good aseptic techniques and safety to tape the lid shut and place the plate in an incubator?

Prevent anaerobic pathogens growing, reduce growth of human pathogens with optimum temperature of 37 and stop condensation from dripping on the agar and spreading contamination.

What’s the 5th step for culturing microorganisms?

After culturing

What’s good aseptic technique and safety after culturing?

Pass an inoculating loop through a blue Bunsen flame and place on a heatproof mat to cool and wipe the workplace with disinfectant.

What’s the purpose for good aseptic techniques and safety after culturing?

Sterilise the inoculating loop and kill any microorganisms on the surface.