Microbial Ecology

, Volume 68, Issue 3, pp 575–583

Patterns of Bacterial Diversity Along a Long-Term Mercury-Contaminated Gradient in the Paddy Soils

  • Yu-Rong Liu
  • Jian-Jun Wang
  • Yuan-Ming Zheng
  • Li-Mei Zhang
  • Ji-Zheng He
Soil Microbiology

DOI: 10.1007/s00248-014-0430-5

Cite this article as:
Liu, YR., Wang, JJ., Zheng, YM. et al. Microb Ecol (2014) 68: 575. doi:10.1007/s00248-014-0430-5

Abstract

Mercury (Hg) pollution is usually regarded as an environmental stress in reducing microbial diversity and altering bacterial community structure. However, these results were based on relatively short-term studies, which might obscure the real response of microbial species to Hg contamination. Here, we analysed the bacterial abundance and community composition in paddy soils that have been potentially contaminated by Hg for more than 600 years. Expectedly, the soil Hg pollution significantly influenced the bacterial community structure. However, the bacterial abundance was significantly correlated with the soil organic matter content rather than the total Hg (THg) concentration. The bacterial alpha diversity increased at relatively low levels of THg and methylmercury (MeHg) and subsequently approached a plateau above 4.86 mg kg−1 THg or 18.62 ng g−1 MeHg, respectively. Contrasting with the general prediction of decreasing diversity along Hg stress, our results seem to be consistent with the intermediate disturbance hypotheses with the peak biological diversity under intermediate disturbance or stress. This result was partly supported by the inconsistent response of bacterial species to Hg stress. For instance, the relative abundance of Nitrospirae decreased, while that of Gemmatimonadetes increased significantly along the increasing soil THg and MeHg concentrations. In addition, the content of SO42−, THg, MeHg and soil depth were the four main factors influencing bacterial community structures based on the canonical correspondence analysis (CCA). Overall, our findings provide novel insight into the distribution patterns of bacterial community along the long-term Hg-contaminated gradient in paddy soils.

Supplementary material

248_2014_430_MOESM1_ESM.docx (29 kb)
Table S1(DOCX 29 kb)
248_2014_430_MOESM2_ESM.docx (37 kb)
Figure S1Regressions between abundance of 16S rRNA gene sequences and methylmercury (MeHg) content. (DOCX 37 kb)
248_2014_430_MOESM3_ESM.docx (64 kb)
Figure S2The relative abundance of bacterial class along the increasing total Hg (THg) and (MeHg) concentrations. (DOCX 63 kb)
248_2014_430_MOESM4_ESM.docx (63 kb)
Figure S3The relative abundance of bacterial order along the increasing THg concentration. (DOCX 62 kb)
248_2014_430_MOESM5_ESM.docx (48 kb)
Figure S4The relative abundance of bacterial order along the increasing (MeHg) concentration. (DOCX 47 kb)

Copyright information

© Springer Science+Business Media New York 2014

Authors and Affiliations

  • Yu-Rong Liu
    • 1
  • Jian-Jun Wang
    • 2
  • Yuan-Ming Zheng
    • 1
  • Li-Mei Zhang
    • 1
  • Ji-Zheng He
    • 1
    • 3
  1. 1.State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijingChina
  2. 2.State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and LimnologyChinese Academy of SciencesNanjingChina
  3. 3.Melbourne School of Land and EnvironmentUniversity of MelbourneParkvilleAustralia

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