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Bacteria in Weathered Basaltic Glass, Iceland

Research output: Contribution to journalArticle

  • Charles S. Cockell
  • Karen Olsson
  • Felicity Knowles
  • Laura Kelly
  • Aude Herrera
  • Thorsteinn Thorsteinsson
  • Viggo Marteinsson

Related Edinburgh Organisations

Original languageEnglish
Pages (from-to)491-507
Number of pages17
JournalGeomicrobiology journal
Volume26
Issue number7
DOIs
StatePublished - 2009

Abstract

Bacteria play an important role in rock weathering and yet their diversity and potential activity in the terrestrial rock weathering environment is poorly understood. Culture and culture-independent methods (16S rDNA) were used to investigate the populations of bacteria inhabiting a basaltic glass/palagonite subglacial (hyaloclastite) deposit subject to weathering in Iceland. The rock hosts a diverse microbial community. The 16S rDNA clones were dominated by Actinobacteria, Proteobacteria, Bacteroidetes and Acidobacteria. Representatives of Gemmatimonadetes and Verrucomicrobia were present. Isolation of organisms on basalt/palagonite yielded only two isolates, an actinobacterium and a Bacteroidetes, showing that the active species, at least in the time scale of laboratory cultivation, are a small proportion of the total diversity. Firmicutes and Actinobacteria were isolated when basalt/palagonite was supplemented with an organic source. Many of the isolates demonstrated tolerance to transition metals (Cr, Cu, Zn, Ni, Co) naturally present in the rock. The growth of the isolates was inhibited at typical pH values for Icelandic rain, which suggests that the increase in pH caused by the consumption of protons in rock weathering, for example by palagonite formation, may play a role in defining which organisms are active. Colonization experiments show that the filamentous growth habit of the actinobacterium isolated on basalt/palagonite allows it to actively invade and colonise the basaltic glass. The filamentous growth of some actinobacteria may be an important contributor to their role in systemic interstitial rock weathering in the natural environment.

    Research areas

  • Actinobacteria, basaltic glass, Iceland, volcanic, weathering, BIOLOGICAL SOIL CRUSTS, PHYLOGENETIC DIVERSITY, MICROBIAL DIVERSITY, VOLCANIC GLASS, ANTIBIOTIC-RESISTANCE, COMMUNITY COMPOSITION, FLOOR BASALT, OCEAN CRUST, SEA-FLOOR, RATES

ID: 1498012