Page 13 - Microbiology in workplace
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GMP Training – Microbiology in the Workplace by www.gmpsop.com
GOOD TO KNOW - DIFFICULTY IN COUNTING MICRO-ORGANISMS
As micro-organisms are constantly multiplying and dying, to get a true count,
multiplication must be slowed or stopped altogether.
Since micro-organisms rarely occur alone, estimates must be made. Estimates
can be made through a process called Total Viable Aerobic Count (TVAC),
which counts the number of colony forming units (CFUs). CFU counting
assumes one colony has originated on the media from one cell, and as such,
would introduce significant error into the count.
Some micro-organisms do not grow together due to toxicity, or because of
different temperature, moisture, oxygen, and nutrient requirements.
How fast can bacteria multiply?
The typical generation time is 30-60 minutes. The time interval ("generation time"
or "doubling time") required for bacteria to divide, and therefore double in
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