Which of the following is NOT a common method for controlling bacterial growth?

Increasing oxygen levels is not a common method for controlling bacterial growth. In fact, many bacteria require low-oxygen or anaerobic conditions to thrive, so simply increasing oxygen levels could potentially promote the growth of certain bacterial species rather than control it.

In contrast, using antibiotics is a well-established method to inhibit bacterial growth or kill bacteria, particularly in clinical settings. Applying heat, such as through pasteurization or sterilization, effectively destroys bacteria by denaturing their proteins and disrupting cell membrane integrity. Refrigeration slows down bacterial growth by reducing the metabolic activity of bacteria, making it a widely used practice for preserving food and preventing spoilage. Each of these methods works through different mechanisms to effectively control bacterial proliferation, highlighting the significance of understanding these techniques in microbiology and infection control.