Effects of mercury compounds on soil microbes

Summary Even low concentrations of mercury compounds in agar media strongly decreased the number of soil microbes that could be isolated on these media.Mercury compounds added to the soil in very high concentrations inhibited CO₂-evolution, dehydrogenase activity, and nitrification. In contrast, the number of microbes increased somewhat in a clay soil treated with HgCl₂. Phenylmercury acetate had a stronger inhibiting effect than HgCl₂. In sandy soil the microbial processes were inhibited more strongly than in clay soil.Mercury compounds present in the soil or added in low concentrations are not expected to seriously disturb organic-matter breakdown, nitrogen mineralization, or the soil-microbe numbers.