Microbial fixation of nitrogen in presence of lanthanum sulphate with sodium molybdate.

The effect of lanthanum sulphate together with 100 micrometer of sodium molybdate show that there is considerable increase in nitrogen fixation and carbon consumption in the culture medium of nitrogen-fixing Azotobacter species A1 and A2, isolated from Allahabad soil. But these combination decrease the nitrogen fixation and carbon consumption in case of another species, Azotobacter A3, of the same soil.