1. routine cultivation of bacteria
Experiment 2
The cultivation of bacteria (1)
routine cultivation of bacteria

2. Contents 1. Media for routine cultivation of bacteria
2. Techniques for bacterial cultivation and
inoculation
3. Growth characteristics of bacteria on/in different
media
4. Metabolic activities of bacteria
5. The physical effect on bacteria and commonly
used sterilizers

3. 1. Media for routine cultivation of bacteria
Media--- The basic ingredients of media
include carbon source、nitrogen source、
inorganic salt 、growth factor and
distilled water etc.

4. 1. basal medium ( agar plate medium)
Classification of culture media
According to function, in general, media can be classified five types:
1. basal medium ( agar plate medium)
2. nutrient medium (blood agar plate medium)
3. selective medium
4. differential medium
5. anaerobic medium.

5. According to physical properties, media can be classified three types:
1. solid medium ( 1.5～2.5% of agar)
agar plate /slant medium
2. semi-solid medium (0.3～0.5% of agar)
3. liquid medium 2 1 1 3

6. 1) isolation cultivation
2. Techniques for bacterial inoculation
Bacterial inoculation is a basic technique of microbiology. The operation must be under sterile condition.
1) isolation cultivation
2) pure cultivation

7. 1) Isolation cultivation
streak a bacterial culture on a nutrient agar plate to separate the individual bacterial cells, each isolated cell will develop into a pure colony after incubation.
continuous streak method
quadrant streak dilution method
method

11. 2) Pure cultivation
transfer a single colony from agar plate or a pure slant culture to liquid medium, slant or semisolid medium to get a pure culture.
subculture into liquid medium
subculture into agar slant/plate
subculture into agar deep tube (semi-solid)

12. 3. Phenomena of bacterial growth
on agar plate (on blood agar plate)
in liquid medium
in semi-solid medium

13. 1) on agar plate
observe the isolated colony on the surface of nutrient agar plate; note size, shape, elevation, margin, surface, transparency and pigment (color of colony).

14. on agar plate -- colony Note: Size 大小 Shape 形状 Elevation 突起 Margin 边缘
Surface 表面
Transparency 透明度
Pigment 色素

15. on blood agar plate
observe hemolysis (complete and incomplete)
phenomena around colony.

16. three growth phenomena will be seen:
3) in liquid medium
three growth phenomena will be seen:
surface growth pellicle 表面生长
uniformly turbid 均匀混浊生长
sediment in bottom 沉淀生长

17. surface growth pellicle
In liquid medium
surface growth pellicle
uniformly turbid
sediment in bottom

18. 4) in semi-solid medium
nonmotile organism
motile organism

19. 4. Metabolic Products and Biochemical Testing

20. Carbohydrate Fermentation Test
溴甲酚紫【pH 5(黄)－pH7(紫)】

21. Methyl Red (MR) Test

22. Voges-Proskauer (VP) Test

23. Indole Test

24. Citrate utilization test

25. I M Vi C test
E.coli
E.Aerogenes

26. Hydrogen Sulfide (H2S ) Production
sulfur amino acid
sulfur inorganic compound
Pb2+
PbS
H2S
（black ）
FeS
Fe2+

27. Urease Test

28. 5. The physical effect on bacteria and commonly used sterilizers
1) Physical factor:
dry、moist、ultraviolet、ultrasonic wave 2) Commonly used sterilizers:
autoclave
dry-air oven
bacteriological filters

29. Experiment manipulation
1. Continuous streak method or quadrant streak method
strain: S.aureus or E.coli
one piece of plate/person
2. Observe phenomena of bacterial growth
on agar plate
in liquid medium
in semi-solid medium

30. Experiment report 1. Continuous streak method or quadrant streak
principle
procedure
result: describe the characteristics of colony
analysis
2. Draw phenomena of bacterial growth