6533b7d5fe1ef96bd1264fe4

RESEARCH PRODUCT

Energy Transduction in Anaerobic Bacteria

subject

description

Anaerobic or facultatively anaerobic bacteria are able to grow in the absence of molecular oxygen by fermentation, anaerobic respiration, anoxygenic photosynthesis, and some other membrane-dependent reactions. Fermentation uses substrate-level phosphorylation for adenosine diphosphate phosphorylation, whereas the other processes rely on the formation of a H + or Na + potential over the membrane and a membrane-potential-driven ATP synthase. In growth reactions providing only a small free energy change, the latter reactions and use of a membrane potential is the preferred mechanism for energy conservation. Fermentation reactions supply products of biotechnological interest like short chain fatty acids, alcohols, H 2 , CO 2 , and methane. Major anaerobic electron acceptors are nitrate, nitrite, sulfate, CO 2 , and metal oxides. Many of the anaerobic electron transport chains use redox loop enzymes for generating the H + potential over the membrane.