Which statement is correct regarding the rate of microbial death during exposure to a microbial control agent?

• A. Microbial death occurs at a constant logarithmic rate.
• B. Microbial death rate is unaffected by the concentration of the control agent.
• C. All microbes in a population die simultaneously when exposed to a control agent.
• D. The rate of microbial death increases over time as more cells die.

Answer: (A)

Verified step by step guidance

1. Understand that microbial death during exposure to a control agent typically follows a predictable pattern rather than all cells dying at once or the rate changing unpredictably.
2. Recall that microbial death is often described as a logarithmic or exponential process, meaning a constant proportion of the population dies per unit time, not a constant number of cells.
3. Recognize that this implies the death rate is constant on a logarithmic scale, which is why we say microbial death occurs at a constant logarithmic rate.
4. Consider that factors like concentration of the control agent can affect the rate, so the death rate is not necessarily unaffected by concentration.
5. Conclude that the correct statement is the one describing microbial death as occurring at a constant logarithmic rate, reflecting the exponential decline in viable cells over time.