Question

What is the decimal reduction time? Example Q: If a microbe had a decimal reduction time of 1 min and starts with 10⁹ cells, how many cells left after 4 mins?

A) The time required to reduce microbial population by 90%
B) The time required to eliminate all microbes
C) The time required for microbial growth
D) The time required for microbial adaptation

Answer 1

The decimal reduction time (DRT) or D-value is the time it takes to kill 90% of a microbial population when exposed to a specific microbial control protocol. In the example given, starting with 10^9 cells and a D-value of 1 minute, after 4 minutes there would be 10^3 cells remaining.

Step-by-step explanation:

The decimal reduction time (DRT) or D-value represents the amount of time it takes to kill 90% of a microbial population when exposed to a specific microbial control protocol.

It is a measure of effectiveness for microbial control methods.

In the given example, if a microbe has a decimal reduction time of 1 minute and starts with 10^9 cells, after 4 minutes there would be 10^3 cells remaining.

This is because every minute, 90% of the population is killed, resulting in a decrease of one order of magnitude in the population.