Final answer:
Bacteria that use oxygen at low concentrations are known as microaerophiles, thriving in environments with 1%-10% oxygen levels, which is below the normal atmospheric condition.
Step-by-step explanation:
Bacteria that use oxygen, but only at low concentration, are classified as microaerophiles. Microaerophiles prefer environments with oxygen levels lower than what is found in normal atmospheric conditions, typically between 1%-10%. These bacteria are able to make ATP through aerobic respiration but can also ferment sugars in conditions where only low levels of oxygen are available. Unlike obligate anaerobes, which are killed by the presence of oxygen, or obligate aerobes that require high concentrations of oxygen, microaerophiles have specific requirements for oxygen that are not too high and not too low.
Microaerophiles are bacteria that use oxygen, but only at low concentrations. These bacteria prefer environments with lower levels of oxygen than normal atmospheric conditions. They make ATP by aerobic respiration and may also ferment sugars aerobically. Examples of microaerophiles include Helicobacter pylori and Campylobacter jejuni.