Listeria monocytogenes can survive in environments that lack oxygen because it is able to generate its energy anaerobically, without oxygen, says Biology Online. It is an example of a facultative anaerobe, which is an organism that has multiple energy-production mechanisms at its disposal, some of which do not require oxygen as a resource.
Organisms generate the energy they need to survive through cellular respiration, which is some sequence of molecular reactions that break down large molecules to liberate energy, as described by About.com. This liberated energy is captured in the form of adenosine triphosphate, or ATP, a small molecule that is chemically well-suited for intracellular energy transfer.
There are different kinds of cellular respiration, notes About.com. Aerobic respiration is the most efficient at capturing energy and uses oxygen molecules as a resource. Anaerobic respiration and fermentation are less efficient, but do not require oxygen. Facultative anaerobes like Listeria monocytogenes can use any of these energy-producing mechanisms, switching from one to the other based on the abundance of available oxygen.
Of the seven species in the Listeria bacterial genus, Listeria monocytogenes is the only one significantly pathogenic to humans, according to the Centers for Disease Control and Prevention. Eating food contaminated with it is the primary cause of Listeriosis, a serious infection that leads to death in about 24 percent of cases, as stated in an article published by the National Institutes of Health.