1. *5 I’s Inoculation – Implanting Microbes into or upon culture media.
Tools and methods in Bacteriology
*5 I’s
Inoculation – Implanting Microbes into or upon culture media.
-Tools used for this are : Loop – swab – needle

2. 1.Media- artificially prepared nutrients
- Bacteria Food – can be broth (soup like) in a test tube or Agar (jello) on Petri dishes

3. 2. Culture- observable growth on/in media
examples: Cloudy Broth or colony on agar
3. Culturing – inoculating microbes into media and encouraging growth
4. Contamination – unwanted microbes
5. Pure culture – only 1 type of microbe

4. B. Incubation
placing microbes in controlled chamber with temperature set at 20C – 40C, usually at 37C (98.6F)

5. C. Isolation – separating bacterial species from each
* Subculture use loop or swab to dip into colony and transfer to new media

6. D. Inspection – preparing (slides) microbes to view with microscopes

7. E. Identification
– determining species based on shape color and other tests
* microscope most important tool for this

8. Figure 6.8 Characteristics of bacterial colonies-overview

9. Culturing Microorganisms
Obtaining Pure Cultures
Aseptic technique
Two common isolation techniques
Streak plates
Pour plates
A colony is a population of cells arising from a single cell or from a group of attached cells 9

10. Streak Plate
Figure 6.10a, b

11. Figure 6.9 Streak plate method of isolation-overview

12. Figure 6.10 Pour plate method of isolation-overview

13. Culturing Media A. Liquid – semisolid- solid B. Counting bacteria in
1. Broth cloudiness
2. Slide grid with microscope
3. Coulter counter

14. Types of media
1. General purpose –grows wide variety of microbe species
2. Selective media – this inhibits the growth of many species, but encourages certain species
3.Differential Media – Wide variety of species but each species looks different

15. Specialty Medias

16. Culture Media
Complex Media/general media: Extracts and digests of yeasts, meat, or plants
Nutrient broth
Nutrient agar
Complex polysaccharide generally not metabolized by microbes

17. Figure 6.11 Slant tube containing solid media
Butt

18. Figure 6.12 An example of the use of a selective medium
Bacterial colonies
Fungal colonies
pH 7.3
pH 5.6

19. Figure 6.13 The use of blood agar as a differential medium
Beta-hemolysis
Alpha-hemolysis
No hemolysis (gamme-hemolysis)

20. Figure 6.15 Use of MacConkey agar as a selective and differential medium-overview

21. Figure 6.16 An anaerobic culture system
Clamp
Airtight lid
Chamber
Palladium pellets to catalyze reaction removing O2
Envelope containing chemicals to release CO2 and H2
Methylene blue (anaerobic indicator)
Petri plates

23. Culturing Microorganisms
Preserving Cultures
Refrigeration
Stores for short periods of time
Deep-freezing
Stores for years
Lyophilization (freeze-drying): Frozen and dehydrated in a vacuum
Stores for decades 23