Which process involves the breakdown of organic material without the presence of oxygen?

The process that involves the breakdown of organic material without the presence of oxygen is anaerobic respiration. In this process, organisms such as certain bacteria and yeast utilize alternative electron acceptors rather than oxygen to produce energy. This method of energy production is essential in environments where oxygen is scarce or unavailable.

During anaerobic respiration, organic matter is decomposed, resulting in the generation of byproducts like methane, alcohol, or organic acids, depending on the specific pathways and organisms involved. This contrasts with aerobic processes, which rely on oxygen and produce different byproducts, most notably carbon dioxide and water.

The other options listed pertain to different mechanisms of decomposition or energy production. Facultative fermentation typically refers to organisms that can switch between aerobic and anaerobic metabolism, which is somewhat misleading in this context since it implies a reliance on the presence of oxygen at least part of the time. Autolysis refers to the self-digestion of cells through the release of enzymes after death, without the indication of either aerobic or anaerobic conditions specifically. Aerobic decomposition directly involves the presence of oxygen and therefore does not fit the criteria of breaking down organic material without oxygen.