Index >> Sulphur Phosphorus and Trace Element Nutrition >> Copper

Copper is precipitated by H₂S producing soil microorganisms. Apart from Desulfovibrio desulfuricans which reduces sulphate, bacteria such as Clostridium lentoputrescens. Proteus vulgaris and Escherichia coli may produce H2S from sul­phur containing amino compounds such as cystine, methionine and glutathione under anaerobic conditions.

That H₂S producing bacteria are in­volved in the precipitation of copper rendering the element insoluble has been clearly demonstrated in experiments with barley and oats. In such ex­periments, the precipitate of copper formed by D. desulfuricans and E. coli were fed to copper-deficient plants and the plants showed no recovery. A second set of plants treated with copper sulphate along with sterilized bac­terial medium recovered from copper-deficiency symptoms. Apparently, in the later case, there was no bacteria-mediated precipitation of copper.