How does a bacterial shaker or rocker benefit laboratory work specifically for aerobic cultures?

• A. It increases the temperature of the culture
• B. It ensures adequate oxygen is supplied
• C. It sterilizes the culture medium
• D. It speeds up the growth of anaerobic bacteria

Answer: (B)

A bacterial shaker or rocker is essential for providing adequate oxygen to aerobic cultures. Aerobic bacteria require oxygen for their metabolic processes, and the movement created by a shaker or rocker enhances the aeration of the culture medium. This agitation increases the surface area of the liquid that is in contact with air, allowing more oxygen to dissolve into the medium and be available for the bacteria.

Thus, by maintaining an environment where oxygen is continuously supplied, the shaker or rocker optimally supports the growth of aerobic organisms, promoting faster and more robust bacterial proliferation. This is particularly important in experiments or processes requiring high cell density or active metabolite production, as the oxygen supply can directly influence the growth rate and health of the cultures involved.

In contrast, options that mention increasing the temperature, sterilizing the culture medium, or speeding up the growth of anaerobic bacteria do not accurately reflect the purpose or function of a shaker or rocker in the context of aerobic cultures. These factors either pertain to unrelated processes or to the characteristics of different microbial growth conditions.