1.7 - Growing and investigating bacteria Flashcards
What can be used for laboratory investigations of bacteria?
Pure cultures on non-pathogenic bacteria
Why might bacteria be used in a laboratory investigation?
To find the effects on antibiotics on bacteria
Why do investigations into bacteria require uncontaminated cultures?
Other bacteria could grow, like pathogens
Where could contamination come from in a laboratory investigation of bacteria?
Skin, the air, soil or the water in the air
What is the liquid or gel you give to a bacteria to culture them?
A culture medium, e.g agar jelly
What is contained in a culture medium? (4)
Nutrients
Carbohydrate as an energy source
Other minerals
Sometimes other chemicals
Once in a culture medium, what do bacteria require to culture?
Warmth and oxygen
What temperature should bacteria be incubated at in school laboratories?
25 degrees celsius
What temperature should bacteria be incubated at in the industry?
35 degrees celsius
What two things should you do to keep a culture of bacteria pure?
- kill all bacteria on the equipment (pass metal loops through flame, boil solutions and agar, etc…)
- prevent microorganisms from getting into equipment (don’t blow on inoculating loop to cool it, etc…)