The Tricky Task of Nitrate/Nitrite Antiport

摘要

Microorganisms often show substantial metabolic diversity to cope with fundamental changes in energy sources and nutrients. This is particularly critical for the essential element nitrogen, whose availability is commonly a growth-limiting factor. In its fully reduced form, NH4~+, nitrogen can be assimilated into amino acids for biosynthetic purposes, and a network of redox reactions serves to interconvert different modifications of the element, preserving free enthalpy in a proton motive force that drives adenosine triphosphate (ATP) synthesis.