Applied Microbiology and Biotechnology

, Volume 101, Issue 5, pp 2163–2175

Mercury alters the bacterial community structure and diversity in soil even at concentrations lower than the guideline values

  • Khandaker Rayhan Mahbub
  • Suresh Ramraj Subashchandrabose
  • Kannan Krishnan
  • Ravi Naidu
  • Mallavarapu Megharaj
Environmental biotechnology

DOI: 10.1007/s00253-016-7965-y

Cite this article as:
Mahbub, K.R., Subashchandrabose, S.R., Krishnan, K. et al. Appl Microbiol Biotechnol (2017) 101: 2163. doi:10.1007/s00253-016-7965-y
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Abstract

This study evaluated the effect of inorganic mercury (Hg) on bacterial community and diversity in different soils. Three soils—neutral, alkaline and acidic—were spiked with six different concentrations of Hg ranging from 0 to 200 mg kg−1 and aged for 90 days. At the end of the ageing period, 18 samples from three different soils were investigated for bacterial community structure and soil physicochemical properties. Illumina MiSeq-based 16s ribosomal RNA (rRNA) amplicon sequencing revealed the alteration in the bacterial community between un-spiked control soils and Hg-spiked soils. Among the bacterial groups, Actinobacteria (22.65%) were the most abundant phyla in all samples followed by Proteobacteria (21.95%), Bacteroidetes (4.15%), Firmicutes (2.9%) and Acidobacteria (2.04%). However, the largest group showing increased abundance with higher Hg doses was the unclassified group (45.86%), followed by Proteobacteria. Mercury had a considerable negative impact on key soil functional bacteria such as ammonium oxidizers and nitrifiers. Canonical correspondence analysis (CCA) indicated that among the measured soil properties, Hg had a major influence on bacterial community structure. Furthermore, nonlinear regression analysis confirmed that Hg significantly decreased soil bacterial alpha diversity in lower organic carbon containing neutral and alkaline soils, whereas in acidic soil with higher organic carbon there was no significant correlation. EC20 values obtained by a nonlinear regression analysis indicated that Hg significantly decreased soil bacterial diversity in concentrations lower than several guideline values.

Keywords

Illumina Miseq Bioavailable mercury Soil DNA 16s rRNA Ecological investigation level (EIL) Toxicity 

Supplementary material

253_2016_7965_MOESM1_ESM.pdf (276 kb)
ESM 1(PDF 276 kb)

Copyright information

© Springer-Verlag Berlin Heidelberg 2016

Authors and Affiliations

  • Khandaker Rayhan Mahbub
    • 1
  • Suresh Ramraj Subashchandrabose
    • 1
  • Kannan Krishnan
    • 1
  • Ravi Naidu
    • 1
  • Mallavarapu Megharaj
    • 1
  1. 1.Global Centre for Environmental Remediation (GCER) and Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC-CARE), Faculty of Science and Information TechnologyThe University of NewcastleCallaghanAustralia

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