Final answer:
C. acnes is a facultative anaerobe, meaning it can grow in both the presence and absence of oxygen.
Step-by-step explanation:
The type of bacteria that C. acnes is in relation to oxygen can be determined through its growth patterns in the presence of oxygen. C. acnes, which stands for Cutibacterium acnes (formerly Propionibacterium acnes), is known to be a facultative anaerobe. This means that it can grow in the presence of oxygen, but it can also grow without it by using fermentation or anaerobic respiration when no oxygen is available. Facultative anaerobes are different from obligate aerobes, which require oxygen to grow, and from obligate anaerobes, which are harmed by the presence of oxygen and cannot grow in its presence at all. Aerotolerant anaerobes do not use oxygen but are not harmed by it, which is not the case with C. acnes as it can utilize oxygen if it's available.