Bacterial Growth Requirement:-
Cultivation of Bacteria:
Culturing of Bacteria:
Culturing is a technique used to isolate a microorganism in a pure culture and used for testing the sensitivity to an antibiotic i.e. to determine the suitable antibiotic for certain microorganism.
e.g. to isolate organism from a specimen, you need culture media, then inoculate the specimen (e.g. urine) by a needle in a zigzag form, then incubate at temperature 37˚C, after 24 hours you see organism growing in pure form, i.e. you found only one type, otherwise it is mixed.
The medium of culturing must contains:
1- Carbon source: carbohydrate, organic salts
2- Nitrogen source: peptone = Digestive protein. Amino acids
3- Essential vitamins (growth factor)
4- Minerals (growth factor)
5- Essential amino acids: in meat extract(beef).
- These ingredients are dissolved in distilled water, the pH is adjusted to 7.2 and then the medium should be sterilized (e.g. by Autoclave).
- Medium is either solid or liquid and some times semisolid.
Solid medium: used for isolation in pure form.