The impact of sludge amendment on methanogen community structure in an upland soil

S. K. Sheppard, A. J. McCarthy, J. P. Loughnane, N. D. Gray, I. M. Head, D. Lloyd

Research output: Contribution to journalArticle

15 Citations (Scopus)

Abstract

In the EU, municipal sewage sludge application to agricultural land has increased dramatically since the ban on dumping at sea came into effect in 1998. There are many concerns related to potential contamination and reduction in plant productivity. In this study, the aim was to assess the impact of repeated long-term soil amendment with anaerobically digested sewage sludge on methanogen diversity in an upland soil ecosystem. Sludge-treated and untreated upland soil samples as well as samples of the sludge used, were analysed for the diversity of methanogens using TGGE, PCR-RFLP and DNA sequence analysis of approximately 490 bp of the mcrA operon. PCR analysis using mcrA specific oligonucleotide primers confirmed the presence of methanogen DNA in treated and untreated soil samples and in sewage sludge. TGGE was used to describe the diversity of methanogen mcrA sequences and the differences in community structure between samples. Ninety-six mcrA gene PCR products were screened using RFLP analysis representing methanogen DNA amplified from anaerobically digested sewage sludge, control soils and sludge treated soils. Fourteen RFP's were detected in all treatments, five of which were common to all three treatments. Thirty-eight cloned amplimers were selected for sequencing and phylogenetic analysis. These included representatives of each RFP. From control soils, sludge and sludged soil samples 15, 16 and 7 clones were sequenced, respectively. Phylogenetic analysis suggested that they represented hitherto uncharacterised mcr genes; 35 of the clones fell into 7 clusters supported by moderate to high bootstrap values. The diversity of methanogens in an upland soil (treated and untreated) and sludge was evaluated and marked differences in the diversity of the methanogen communities was observed between the treatments. Our results indicate that sludge application may reduce soil methanogen community diversity.

Original languageEnglish
Pages (from-to)147-162
Number of pages16
JournalApplied Soil Ecology
Volume28
Issue number2
Early online date15 Sep 2004
DOIs
Publication statusPublished - 1 Feb 2005

Keywords

  • Methanogens
  • Microbial diversity
  • Molecular ecology
  • Sewage sludge
  • Soil

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics
  • Soil Science
  • Ecology

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