Nitrogen Fixation by Sulphate-reducing Bacteria

SUMMARY: Nitrogen fixation has been obained with strains of Desulfovibrio vulgaris and D. gigas, organisms hitherto believed to be incapable of using molecular nitrogen. Fixation has been demonstrated by increases in total nitrogen and by uptake of 15N2. Fixation of N2 may be widespread in this genus of the sulphate-reducing bacteria.