title: Pioneer microbial communities of the Fimmvörðuháls lava flow, Eyjafjallajökull, Iceland.
abstract: Little is understood regarding the phylogeny and metabolic capabilities of the earliest colonists of volcanic rocks, yet these data are essential for understanding how life becomes established in and interacts with the planetary crust, ultimately contributing to critical zone processes and soil formation. Here, we report the use of molecular and culture-dependent methods to determine the composition of pioneer microbial communities colonising the basaltic Fimmvörðuháls lava flow at Eyjafjallajökull, Iceland, formed in 2010. Our data show that 3 to 5 months post eruption, the lava was colonised by a low-diversity microbial community dominated by Betaproteobacteria, primarily taxa related to non-phototrophic diazotrophs such as Herbaspirillum spp. and chemolithotrophs such as Thiobacillus. Although successfully cultured following enrichment, phototrophs were not abundant members of the Fimmvörðuháls communities, as revealed by molecular analysis, and phototrophy is therefore not likely to be a dominant biogeochemical process in these early successional basalt communities. These results contrast with older Icelandic lava of comparable mineralogy, in which phototrophs comprised a significant fraction of microbial communities, and the non-phototrophic community fractions were dominated by Acidobacteria and Actinobacteria.
authors.affiliation: Geomicrobiology Research Group, CEPSAR, Open University, Milon Keynes, MK7 6AA, UK, laurackelly@live.ie.
authors.forename: Laura C
authors.initials: LC
authors.lastname: Kelly
authors.forename: Charles S
authors.initials: CS
authors.lastname: Cockell
authors.forename: Thorsteinn
authors.initials: T
authors.lastname: Thorsteinsson
authors.forename: Viggó
authors.initials: V
authors.lastname: Marteinsson
authors.forename: John
authors.initials: J
authors.lastname: Stevenson
mesh_terms: D020562:Betaproteobacteria / Q000145:classification* / Q000302:isolation & purification; D015169:Colony Count, Microbial; D004269:DNA, Bacterial / Q000235:genetics; D015723:Gene Library; D007055:Iceland; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012987:Soil / Q000737:chemistry; D012988:Soil Microbiology; D018707:Volcanic Eruptions
chemical_list: D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S; D012987:Soil