Which of the following is the most appropriate method to determine the species of an unknown bacterium?

• A. Estimating the growth rate in nutrient broth
• B. Performing a series of biochemical tests and comparing the results to known species profiles
• C. Observing the color of the bacterial colony only
• D. Measuring the size of the bacterium under a microscope

Answer: (B)

Verified step by step guidance

1. Understand that identifying the species of an unknown bacterium requires analyzing specific characteristics that distinguish one species from another.
2. Recognize that estimating growth rate in nutrient broth provides general information about bacterial growth but is not specific enough to identify species.
3. Know that observing colony color or measuring bacterial size under a microscope gives limited information and often overlaps among different species.
4. Learn that performing a series of biochemical tests evaluates metabolic and enzymatic activities unique to bacterial species, providing a detailed profile.
5. Compare the biochemical test results of the unknown bacterium to known species profiles in reference databases or manuals to accurately determine its species.