Biology - Micro organisms and their applications Flashcards
What is binary fission?
Asexual reproduction of bacteria in which they copy their DNA and divide into two. Simple form of cell division.
What are some ways to culture bacteria?
nutrient broth solution (on an agar plate) allows a liquid or gel to provide all the nutrients needed for bacteria to grow successfully.
How are agar plates/petri dishes made?
Agar plates are created by pouring hot molten agar into sterile petri dishes, which is then allowed to set.
Why are aseptic techniques used on an agar plate?
To sterilise the agar plate and stop other contaminating bacteria from growing.
How can aseptic techniques be used to avoid contamination?
1) An inoculating loop is sterilised by being heated in a Bunsen flame.
2) The loop is dipped in a liquid bacteria
3) Lift lid of petri dish ensuring its not fully removed to prevent air contamination.
4) Draw a line across the agar.
5) Inoculating loop is heated again
6)Agar plate is sealed with tape and put in incubator at 25°C for 1-2 days.
What are fermenters?
Fermenters are containers used to grow bacteria and fungi in large amounts. e.g. Penicillium mould for producing penicillin (an antibiotic).
What is the function of the Steam inlet in a fermenter?
Hot steam sterilises the inside of the fermenter.
prevents contamination by unwanted micro-organisms
What is the function of the Nutrient inlet in a fermenter?
Allows sterile nutrients to enter the fermenter
Penicillium need nutrients so that they can grow and reproduce
What is the function of the Water jacket with cooling water in a fermenter?
Keeps the temperature inside constant
Penicillium need oxygen for aerobic respiration
What is the function of the Filter on air inlet in a fermenter?
Stops micro-organisms getting inside the fermenter
An aseptic precaution to prevent contamination by unwanted micro-organisms
What is the function of the Stirring paddles in a fermenter?
Keeps the mixture inside the fermenter agitated (stirred)
Mixes the micro-organisms with the nutrients and keeps the temperature even
What is the function of the pH probe and intake valve for acid and alkali in a fermenter?
The pH inside the fermenter is monitored to check it is at the optimum value
Penicillium need to be maintained at pH 6.5, the optimum for the fungus
