Conditions Necessary For Culturing Bacteria

Question 1

What are the 5 conditions necessary for culturing bacteria?

Answer 1

Nutrients
Growth factors
Suitable temperatures
Suitable pH
Oxygen

Question 2

What nutrients do bacteria need?

Answer 2

Water, carbon, an energy source such as glucose, and nitrogen for amino acid synthesis. This is is a nutrient broth or medium solidified w agar.

Question 3

What growth factors do bacteria need?

Answer 3

Vitamins eg biotin and mineral salts.

Question 4

What is the optimum temperature for culturing bacteria?

Answer 4

It is regulated by enzymes so 25-45 degrees is suitable for most bacteria. For mammalian pathogens it is around 37.5.

Question 5

What is the suitable pH for culturing bacteria?

Answer 5

Slightly alkaline - 7.4 whereas fungi grow better in neutral to slightly acidic conditions.

Question 6

What classification decides how much oxygen bacteria need?

Answer 6

If they’re obligate aerobes (need it), facultive aerobes (function with or without) or obligate anaerobes (can’t function with it)

Question 7

What are the different ways to describe culture media?

Answer 7

A defined medium - known ingredients
Selective medium - only allows certain bacteria to grow
Undefined medium - contains unknown ingredients because they contain eg yeast extract