BIOS
BIOS242/ BIOS 242 LAB PRACTICUM: (NEW 2025/
2026 UPDATE) FUNDAMENTALS OF MICROBIOLOGY | QS &
AS| GRADE A| 100% CORRECT - CHAMBERLAIN
1. Special Stain: Targets specific structures (e.g., endospores, flagella). -
Examples: Endospore stain, Capsule stain.
2. Pasteurization Purpose: Reduces microbial load to prevent food
spoilage and enhance safety.
3. Pasteurization Process (Labster): LTLT Pasteurization :Low
Temperature, Long Time: 63°C for 30 minutes.
HTST Pasteurization: High Temperature, Short Time: 72°C for 15 seconds.
UHT Pasteurization: Ultra-High Temperature: 135°C for 2-5 seconds.
4. Food spoilage: Caused by microbial toxins, enzymes, and fermentation.
5. Purpose of Streak Plate Method: Purpose: To isolate pure bacterial
colonies for study.
Process:
Streak a small sample onto agar using a sterilized loop.
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Spread the inoculum into different sections to separate cells.
Isolated cells grow into distinct colonies.
6. HEPA Filters: Function: High-Efficiency Particulate Air filters remove
99.97% of particles e 0.3 microns. Used in BSL-3 and BSL-4 labs.
Filters microbes and particulates using synthetic fibers or fiberglass
7. Bacterial Multiplication and Doubling Time: Process: Bacteria
reproduce by binary fission.
Doubling Time: The time it takes for a bacterial population to double..
8. Growth Curve Stages: Includes Lag Phase, Log Phase/ Exponential
phase, Stationary Phase, and Death Phase.
9. Lag Phase: Cells adjust to the environment; no division occurs.
10. Log Phase/Exponential growth: The Log or Exponential Phase of the
Growth Curve Will Continue as Longas Environmental Conditions and
Nutrition are Favourable.
BIOS242/ BIOS