1. Exercise 18: Motility Determination Read results
Lab 7 Goals and Objectives:
Exercise 18: Motility Determination
Read results
Exercise 27: Effect of Oxygen on Growth
Understand FTM patterns of growth
Unknown Project
Data collection for profiles
Each pair get one organism to collect data on to share with the class to develop profiles of all possible organisms.
Each person inoculate one BHIA streak for isolation plate and one BHI broth of assigned organism

2. Exercise 18: Motility Determination
Motility Test Medium
Inoculation method: vertical single stab with straight needle
Contains: nutrient medium with low (0.5%) agar concentration (semisolid) and TTC which changes from colorless to dark pink in the presence of bacterial growth (enhances visualization)
Discriminates motility (presence of flagella), ability to “swim” through media
Results: organism growing only in line of inoculation = non-motile
organism appears as haze beyond line of inoculation = motile
Figure 18.4

3. Motility Test Media Results
Non-motile
Motile
Non
Motile

4. Exercise 27: Effect of Oxygen on Growth
Obligate aerobes: 20% O2
Obligate anaerobes: O2 toxic
Facultative: w/ or w/o, better with O2
Microaerophiles: 5-10% O2
Aerotolerant: ignore O2
Fig 27.1

5. Fig 27.1 Fluid Thioglycolate Medium (FTM)
Inoculation method: loop transfer, careful mixing, screw cap must be loose
Contains: rich medium with very low agar content (viscous)
Sodium thioglycolate (removes oxygen)
Resazurin oxygen indicator (pink when oxidized: O2 present)
Discriminates oxygen requirements: obligate aerobes, obligate anaerobes, facultative anaerobes, microaerophiles, aerotolerant
Results: growth only at top = obligate aerobe
growth only at bottom = obligate anaerobe
even growth throughout = aerotolerant
heavy growth at top, lighter growth at bottom = facultative
growth only in middle = microaerophile
Fig 27.1

6. Supplement pg 52
Growth Patterns Observed in FTM Tubes

7. The gas pack releases H2. This combines with the O2 in the air creating water. The oxygen is chemically removed from the air as it gets bound by the hydrogen to form water molecules, resulting in an anaerobic environment in the jar.

8. Fig 27.4 Fig 27.2 Brewer’s Anaerobic Agar
Inoculation method: surface streak with loop, must be incubated in Brewer’s
anaerobic jar (water + gas pack = H2 + CO2, H2 combines with O2 creating H2O, sealed jar is oxygen free). Inoculate in conjunction with a second plate in aerobic 20% oxygen atmosphere to determine O2 needs.
Contains: Nutrient agar with sodium thioglycolate and resazurin (see FTM)
Discriminates oxygen requirements if read in conjunction with normal aerobic incubated plate: obligate aerobes, obligate anaerobes, facultative anaerobes, aerotolerant
Results: growth on aerobic agar only = obligate aerobe
growth on anaerobic agar only = obligate anaerobe
even growth on both = aerotolerant
heavy growth on aerobic, lighter growth on anaerobic = facultative
Fig 27.4
Fig 27.2

9. Obligate anaerobes: O2 toxic Obligate aerobes: 20% O2
Which Groups Grow on Brewer’s Anaerobic Agar In the Anaerobic Jar?
Which Groups Grow on Brewer’s in 20% Oxygen?
Brewer’s No Oxygen
Brewer’s 20% Oxygen
Obligate anaerobes: O2 toxic
Obligate aerobes: 20% O2
Aerotolerant: ignore O2
Facultative: w/ or w/o, better with O2
Microaerophiles: 5-10% O2

10. Klebsiella pneumoniae Proteus vulgaris Pseudomonas aeruginosa
Possible Unknowns:
Bacillus subtilis
Enterobacter cloacae
Escherichia coli
Klebsiella pneumoniae
Proteus vulgaris
Pseudomonas aeruginosa
Salmonella typhimurium
Shigella flexneri
Staphylococcus aureus
Staphylococcus epidermidis
Enterococcus (Streptococcus) faecalis
Streptococcus pyogenes

11. Exercise 18: Motility Determination Read results
Lab 7 Goals and Objectives:
Exercise 18: Motility Determination
Read results
Exercise 27: Effect of Oxygen on Growth
Understand FTM patterns of growth
Unknown Project
Data collection for profiles
Each pair get one organism to collect data on to share with the class to develop profiles of all possible organisms.
Each person inoculate one BHIA streak for isolation plate and one BHI broth of assigned organism