Sekundäratmung

Sekundäratmung refers to an alternative metabolic pathway used by some organisms to generate energy, particularly under conditions where primary respiration is limited or unavailable. This process often involves the use of electron acceptors other than oxygen, which is the typical final electron acceptor in aerobic respiration.

In many cases, Sekundäratmung utilizes inorganic compounds such as nitrate, sulfate, or iron as terminal electron acceptors. For instance, nitrate reduction by certain bacteria allows them to respire anaerobically, producing nitrogenous compounds as byproducts. Similarly, sulfate-reducing bacteria can use sulfate to oxidize organic matter, yielding hydrogen sulfide.

This metabolic flexibility is crucial for survival in environments where oxygen is scarce, such as deep sediments, the anoxic zones of aquatic ecosystems, or within the digestive tracts of animals. Sekundäratmung plays a significant role in biogeochemical cycles, contributing to the transformation of various elements in nature. The efficiency of Sekundäratmung is generally lower than that of aerobic respiration, resulting in less energy yield per molecule of substrate oxidized. However, it provides a vital means of energy production for many microbial communities.