Cockell, Charles; Olsson, Karen; Knowles, Felicity; Kelly, Laura; Herrera, Aude; Thorsteinsson, Thorstein and Marteinsson, Viggo
|DOI (Digital Object Identifier) Link:||http://dx.doi.org/10.1080/01490450903061101|
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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.
|Item Type:||Journal Article|
|Copyright Holders:||2009 Taylor & Francis|
|Keywords:||Actinobacteria; basaltic glass; Iceland; volcanic; weathering|
|Academic Unit/Department:||Science > Physical Sciences
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|Interdisciplinary Research Centre:||Centre for Earth, Planetary, Space and Astronomical Research (CEPSAR)|
|Depositing User:||Charles Cockell|
|Date Deposited:||10 Nov 2009 10:40|
|Last Modified:||14 Nov 2012 10:05|
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