Dynamic Microbial Community Associated with Iron–Arsenic Co-Precipitation Products from a Groundwater Storage System in Bangladesh
- 819 Downloads
The prokaryotic community in Fe–As co-precipitation product from a groundwater storage tank in Bangladesh was investigated over a 5-year period to assess the diversity of the community and to infer biogeochemical mechanisms that may contribute to the formation and stabilisation of co-precipitation products and to Fe and As redox cycling. Partial 16S rRNA gene sequences from Bacteria and Archaea, functional markers (mcrA and dsrB) and iron-oxidising Gallionella-related 16S rRNA gene sequences were determined using denaturing gradient gel electrophoresis (DGGE). Additionally, a bacterial 16S rRNA gene library was also constructed from one representative sample. Biogeochemical characterization demonstrated that co-precipitation products consist of a mixture of inorganic minerals, mainly hydrous ferric oxides, intimately associated with organic matter of microbial origin that contribute to the chemical and physical stabilisation of a poorly ordered structure. DGGE analysis and polymerase chain reaction-cloning revealed that the diverse bacterial community structure in the co-precipitation product progressively stabilised with time resulting in a prevalence of methylotrophic Betaproteobacteria, while the archaeal community was less diverse and was dominated by members of the Euryarchaeota. Results show that Fe–As co-precipitation products provide a habitat characterised by anoxic/oxic niches that supports a phylogenetically and metabolically diverse group of prokaryotes involved in metal, sulphur and carbon cycling, supported by the presence of Gallionella-like iron-oxidizers, methanogens, methylotrophs, and sulphate reducers. However, no phylotypes known to be directly involved in As(V) respiration or As(III) oxidation were found.
KeywordsTotal Dissolve Nitrogen Prokaryotic Community Candidate Division mcrA Gene dsrB Gene
The authors would like to thank Dr. Emanuele Costa and Dr Linda Pastero. (Dipartimento di Scienze Mineralogiche e Petrologiche, Universita degli Studi di Torino) for their support in Scanning Electron Microscopy and HG-ICP-AES analysis, respectively. This work was supported by the Italian Research Program of National Interest (PRIN 2008) for the financial support of the research. Rishilpi Development Project Bangladesh and Ms. R. Ferdousi are gratefully acknowledged for the logistic support.
- 2.Anthony C (1982) The biochemistry of methylotrophs. Academic, New YorkGoogle Scholar
- 3.Araujo JC, Teran FC, Oliveira RA, Nour EAA, Montenegro MAP, Campos JR, Vazoller RF (2003) Comparison of hexamethyidisilazane and critical point drying treatments for SEM analysis of anaerobic biofilms and granular sludge. J Electron Microsc 52:429–433Google Scholar
- 6.BGS, DPHE (2001) Arsenic contamination of groundwater in Bangladesh. In: Kinniburgh, DG, Smedley, P.L. (ed.) British Geological Survey (Technical Report, WC/00/19). British Geological Survey, KeyworthGoogle Scholar
- 19.Grosskopf R, Stubner S, Liesack W (1998) Novel euryarchaeotal lineages detected on rice roots and in the anoxic bulk soil of flooded rice microcosms. Appl Environ Microbiol 64:4983–4989Google Scholar
- 21.Hall TA (1999) BioEdit: a user-friendly biological sequence alignment editor and analysis program for Windows 95/98/NT. Nucleic Acids Symp Ser 41:95–98Google Scholar
- 26.Hering JG, Kneebone PE (2002) Biogeochemical controls on arsenic occurrence and mobility in water supplies. In: Frankenberger WT (ed) Environmental chemistry of arsenic. Marcel Dekker, New York, pp 155–180Google Scholar
- 37.Lane DJ (1991) 16S/23S rRNA sequencing. In: Stackebrandt E, Goodfellow M (eds) Nucleic acid techniques in bacterial systematics. Wiley, New York, pp 115–175Google Scholar
- 43.Luton PE, Wayne JM, Sharp RJ, Riley PW (2002) The mcrA gene as an alternative to 16S rRNA in the phylogenetic analysis of methanogen populations in landfill. Microbiology-Sgm 148:3521–3530Google Scholar
- 68.Violante A, Krishnamurti GSR, Huang PM (2002) Impact of organic substances on the formation and trasformation of metal oxides in soil environments. In: Huang PM, Bollag JM, Senesi N (eds) Interactions between soil particles and microorganisms. Wiley, Chichester, UK, pp 133–171Google Scholar
- 73.Webster G, Sass H, Cragg BA, Gorra R, Knab NJ, Green CJ, Mathes F, Fry JC, Weightman AJ, Parkes RJ (2011) Enrichment and cultivation of prokaryotes associated with the sulphate-methane transition zone of diffusion-controlled sediments of Aarhus Bay, Denmark, under heterotrophic conditions. FEMS Microbiol Ecol 77:248–263PubMedCrossRefGoogle Scholar