Certified Professional Food Safety (CP-FS) Practice Exam

Which phase of bacterial presence in food is characterized by the fastest increase in populations?

1. Lag Phase

2. Log Phase

3. Stationary Phase

4. Death Phase

The correct answer is: Log Phase

The phase characterized by the fastest increase in bacterial populations is the Log Phase, also known as the exponential phase. During this stage, bacteria that have adjusted to their environment begin to divide at a rapid rate, leading to exponential growth. This means that the number of bacterial cells doubles with each generation time, which can occur very quickly under optimal conditions, such as the right temperature, pH, and nutrient availability. As the bacteria continue to reproduce, the overall population can increase dramatically in a short period, making this phase critical in understanding how bacterial contamination can proliferate rapidly in food. In contrast, during the Lag Phase, bacteria are adjusting to their environment and not yet dividing significantly, while the Stationary Phase sees growth rate plateau due to nutrient depletion or waste accumulation. The Death Phase involves the decline of bacterial numbers as resources become insufficient for continued growth. Understanding these phases is key in food safety to prevent foodborne illnesses.