DNA- and RNA-derived assessments of fungal community composition in soil amended with sewage sludge rich in cadmium, copper and zinc

• Published in: Soil biology & biochemistry 2008-09, Vol.40 (9), p.2358-2365
• Main Authors: Anderson, Ian C., Parkin, Pamela I., Campbell, Colin D.
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; Biochemistry and biology; Biological and medical sciences; cadmium; Chemical, physicochemical, biochemical and biological properties; copper; Denaturing gradient gel electrophoresis; Fundamental and applied biological sciences. Psychology; Fungal diversity; General agronomy. Plant production; Heavy metals; Internal transcribed spacer (ITS); internal transcribed spacers; land application; microbial activity; microbial genetics; molecular sequence data; Other nutrients. Amendments. Solid and liquid wastes. Sludges and slurries; Physics, chemistry, biochemistry and biology of agricultural and forest soils; ribosomal DNA; ribosomal RNA; rRNA; RT-PCR; Sewage sludge; Soil and water pollution; soil ecology; soil fungi; soil organic matter; Soil science; Soil-plant relationships. Soil fertility. Fertilization. Amendments; species diversity; zinc
• ISSN: 0038-0717; 1879-3428
• DOI: 10.1016/j.soilbio.2008.05.015

Current UK legislation permits the application of sewage sludge to agricultural land provided concentrations of heavy metals in soil do not increase above maximum permissible limits. However, even within the defined limits, we do not know how an increase in soil heavy metal concentrations is likely to affect biological diversity and activity. Here we report on the effects of sewage sludge addition, including sludge rich in the metals cadmium, copper and zinc, on soil fungal community composition using both an rDNA and rRNA DGGE approach. Sewage sludge addition altered fungal ITS-DGGE banding patterns, however, there were no additional effects of an increase in soil heavy metal concentrations. Similar results were obtained for the full range of copper rich sludge treatments even when copper concentrations were well above the maximum permissible limits. Our data therefore demonstrate that although an increase in soil organic matter content alters soil fungal community diversity and composition, increasing soil concentrations of cadmium, copper and zinc up to current legislative limits had little additional effect regardless of whether rRNA or rDNA was analysed. This suggests that current UK limits for these three heavy metals are within a concentration range that the dominant soil fungi at this field site can tolerate.