noun, plural: microaerophiles
An organism that lives in environment that only has a low level of oxygen
Oxygen is essential to many forms of life. It plays a crucial role in various biochemical and physiological processes, such as in cellular respiration. Its presence makes cellular respiration about ten times more efficient in yielding ATP. It is a colorless, tasteless, oderless, gaseous element that abounds in the atmosphere. Microorganisms, most especially, may be classified according to the need of or tolerance to atmospheric oxygen. Those that utilize oxygen for growth and survival are referred to as aerobes. They use oxygen for metabolizing substances through cellular respiration. Those that do not use oxygen and prefer anaerobic environments are called anaerobes. There are another group of microorganisms, called microaerophiles, that may use oxygen when carrying out aerobic respiration. They live in an environment where oxygen level is low. Some of the microaerophiles can also perform anaerobic respiration. Examples of microaerophiles are Borrelia burgdorferi, a species of spirochaete bacteria that causes Lyme disease in humans, and Helicobacter pylori, a species of proteobacteria that has been linked to peptic ulcers and some types of gastritis.