The contribution of soil constituents to adsorption of extracellular DNA by soils.

The adsorption of DNA by an andosol was much greater than that by a fluvisol or acrisol. The decrease in soil organic matter on treatment with hydrogen peroxide (H(2)O(2)) little affected DNA adsorption per weight of the particles, implying that the organic matter is not involved in the adsorption. The acid oxalate treatment of the H(2)O(2)-treated soils decreased DNA adsorption. Among soil constituents, acid oxalate-extractable materials such as allophane and noncrystalline Al and Fe oxides are likely to make a major contribution to the adsorption of DNA.