Méndez-García, Celia2; Mesa, Victoria2; Sprenger, Richard Remko11; Richter, Michael3; Diez, María Suárez4; Solano, Jennifer5; Bargiela, Rafael6; Golyshina, Olga V7; Manteca, Angel2; Ramos, Juan Luis8; Gallego, José R9; Llorente, Irene10; Martins Dos Santos, Vitor Ap4; Jensen, Ole N11; Peláez, Ana I2; Sánchez, Jesús2; Ferrer, Manuel6
1 Department of Biochemistry and Molecular Biology, Faculty of Science, SDU2 Departamento de Biología Funcional-IUBA, Universidad de Oviedo, Oviedo, Spain.3 Ribocon GmbH, Bremen, Germany.4 Chair of Systems and Synthetic Biology, Wageningen University, Wageningen, The Netherlands.5 Department of Bioremediation, Bio-Iliberis R&D, Granada, Spain.6 Department of Applied Biocatalysis, Consejo Superior de Investigaciones Científicas (CSIC), Institute of Catalysis, Madrid, Spain.7 School of Biological Sciences, Bangor University, Gwynedd, UK.8 Consejo Superior de Investigaciones Científicas (CSIC), Estación Experimental del Zaidín, Granada, Spain.9 Departamento de Explotación y Prospección de Minas-IUBA, Universidad de Oviedo, Oviedo, Spain.10 Centro Nacional de Investigaciones Metalúrgicas, CSIC, Madrid, Spain.11 Department of Biochemistry and Molecular Biology, Faculty of Science, SDU
Microbial stratification in low pH (sub)oxic AMD
Macroscopic growths at geographically separated acid mine drainages (AMDs) exhibit distinct populations. Yet, local heterogeneities are poorly understood. To gain novel mechanistic insights into this, we used OMICs tools to profile microbial populations coexisting in a single pyrite gallery AMD (pH ∼2) in three distinct compartments: two from a stratified streamer (uppermost oxic and lowermost anoxic sediment-attached strata) and one from a submerged anoxic non-stratified mat biofilm. The communities colonising pyrite and those in the mature formations appear to be populated by the greatest diversity of bacteria and archaea (including 'ARMAN' (archaeal Richmond Mine acidophilic nano-organisms)-related), as compared with the known AMD, with ∼44.9% unclassified sequences. We propose that the thick polymeric matrix may provide a safety shield against the prevailing extreme condition and also a massive carbon source, enabling non-typical acidophiles to develop more easily. Only 1 of 39 species were shared, suggesting a high metabolic heterogeneity in local microenvironments, defined by the O2 concentration, spatial location and biofilm architecture. The suboxic mats, compositionally most similar to each other, are more diverse and active for S, CO2, CH4, fatty acid and lipopolysaccharide metabolism. The oxic stratum of the streamer, displaying a higher diversity of the so-called 'ARMAN'-related Euryarchaeota, shows a higher expression level of proteins involved in signal transduction, cell growth and N, H2, Fe, aromatic amino acids, sphingolipid and peptidoglycan metabolism. Our study is the first to highlight profound taxonomic and functional shifts in single AMD formations, as well as new microbial species and the importance of H2 in acidic suboxic macroscopic growths.The ISME Journal advance online publication, 16 January 2014; doi:10.1038/ismej.2013.242.