Abstract
Vibrio succinogenes grew anaerobically at the expense of formate oxidation, with nitrous oxide (N2O) serving a terminal oxidant. N2O was quantitatively reduced to dinitrogen (N2). In the presence of 5 x 10(-2) atm (ca. 5 kPa) of acetylene (C2H2), which inhibits the reduction of N2O, growth of V. succinogenes was completely inhibited. Nitrate was reduced to nitrite or to ammonia, depending on the extent of availability of formate, but N2 was not produced by reduction of nitrate. During the reduction of nitrate to ammonia, all eight electrons transported to a molecule of nitrate appeared to be coupled for energy-yielding reactions.