Final answer:
Bacteria that require oxygen to sustain life are known as aerobic bacteria, which utilize oxygen for aerobic respiration, in contrast to anaerobic bacteria, including obligate anaerobes, facultative anaerobes, and microaerophiles. Aerobic bacteria are the correct category for these oxygen-requiring organisms. So, the correct option is C).
Step-by-step explanation:
Bacteria that require oxygen to sustain life are called aerobic bacteria. These organisms use oxygen to convert food into energy through the process of aerobic respiration. In contrast to aerobic bacteria, anaerobic bacteria do not require oxygen and may even be killed by its presence. These include obligate anaerobes which die in the presence of oxygen and facultative anaerobes which can survive with or without oxygen by switching between aerobic respiration and fermentation.
Additionally, there are microaerophiles, bacteria that require lower levels of oxygen than are present in the atmosphere, and may necessitate increased levels of carbon dioxide. These bacteria employ aerobic respiration and may also ferment sugars aerobically. Lastly, aerotolerant anaerobes do not utilize oxygen but are not affected by its presence. To properly categorize these bacteria, one must consider their growth conditions seen in thioglycolate tube experiments, where the bacteria's oxygen requirement is visually apparent by their growth patterns. Based on this, the correct option to categorize bacteria that require oxygen to sustain life is C) Aerobic bacteria.