Induction of a dissimilatory reduction pathway of nitrate in Halobacterium of the Dead Sea. A possible role for the 2 Fe-ferredoxin isolated from this organism

The processes involved in nitrate metabolism in Halobacterium of the Dead Sea are part of a dissimilatory pathway operating in these bacteria. The induction of both nitrate and nitrite reductases is shown to depend on the presence of nitrate and of anaerobic conditions. The gas products of the denitrification process were identified as nitrous oxide and nitrogen. Some properties of two of the enzymes involved in this process, nitrate and nitrite reductases, are reported. It is shown that the 2 Feferredoxin, which is present in large quantities in Halobacterium of the Dead Sea, can serve as an electron donor for nitrite reduction by nitrite reductase. It is suggested that the presence of a dissimilatory pathway for the reduction of nitrate in Halobacterium of the Dead Sea can be used as a tool for its classification.