Microbial colonization in diverse surface soil types in Surtsey and diversity analysis of its subsurface microbiota

Abstract

Abstract. Colonization of life on Surtsey has been observed systematically since the formation of the island 50 years ago. Although the first colonisers were prokaryotes, such as bacteria and blue-green algae, most studies have been focused on the settlement of plants and animals but less on microbial succession. To explore microbial colonization in diverse soils and the influence of associated vegetation and birds on numbers of environmental bacteria, we collected 45 samples from different soil types on the surface of the island. Total viable bacterial counts were performed with the plate count method at 22, 30 and 37 • C for all soil samples, and the amount of organic matter and nitrogen (N) was measured. Selected samples were also tested for coliforms, faecal coliforms and aerobic and anaerobic bacteria. The subsurface biosphere was investigated by collecting liquid subsurface samples from a 181 m borehole with a special sampler. Diversity analysis of uncultivated biota in samples was performed by 16S rRNA gene sequences analysis and cultivation. Correlation was observed between nutrient deficits and the number of microorganisms in surface soil samples. The lowest number of bacteria (1 × 10 4

Authigenic Mineral Texture in Submarine 1979 Basalt Drill Core, Surtsey Volcano, Iceland

“…At 157.1‐m depth, fine‐scale protrusions around altered vesicle rinds in a basaltic lapillus (Figures and S1) resemble biomediated microchannels that occur along irregular alteration fronts between fresh and altered glass in older basalts (e.g., Furnes et al, , Figure 4; Fisk et al, , Figure 2; Walton, , Figures and ). Bacterial and archaeal communities were detected in borehole fluids near this depth in 2009 (Marteinsson et al, ), suggesting that microbial processes could, potentially, have played a role in the alteration of freshly erupted basaltic tephra near the preeruption seafloor. By contrast, linear microstructures with complex nanocrystalline clay mineral and zeolite texture represent microcorrosion of basaltic glass and olivine crystals in fractured lapilli, yet these have not been described in previous literature (Figures ).…”

Time-lapse characterization of hydrothermal seawater and microbial interactions with basaltic tephra at Surtsey Volcano

“…For future reference, does Methanobacteriales fall under a different set of taxonomy and nomenclature rules?-like archaeal sequences at 172 m (54 • C) (site 1) and an archaeal community dominated by Archaeoglobus-like 16S rRNA sequences at 145 m (80 • C) (site 2) (Jakobsson and Moore, 1986;Olafsson and Jakobsson, 2009;Marteinsson et al, 2015).…”

“…3b). This subsurface microbial community is quite possibly indigenous, since it occurs below a > 120 • C thermal barrier at 100 m depth that prevents the downward dissemination of surface organisms (Marteinsson et al, 2015). Microbial colonization has been recognized as one of the primary drivers of alteration in ridge crest seafloor basalts and has important implications for global element budgets, seafloor and seawater exchange, and biogeochemical cycles (Thorseth et al, 2001;Furnes et al, 2007;Santelli et al, 2008;Edwards et al, 2012).…”

“…The diversity, abundance, and function of potentially endemic communities of microorganisms will be analyzed by DNA extraction and next generation sequencing of metagenomes and 16S rRNA genes. The functioning of the microbiome will be investigated by transcriptomic analysis and strain isolations (Marteinsson et al, 2015). Assessments of the geochemical composition of hydrothermal seawater, reaction progress associated with water-rock-microbiological interaction and inorganic chemical energy available in the hydrothermal system, will be combined with equilibrium reaction models to describe affinities for chemosynthesis and tephra alteration and provide constraints on the potential energy available for microbial metabolism.…”

“…A recent study of hot fluids in the 1979 drill hole (Fig. 3b) has identified for the first time potentially indigenous thermophilic bacteria and archaea deep in the center of an isolated Neogene volcanic island (Marteinsson et al, 2015). In the SUSTAIN project, studies of microbial colonization of the altered subterrestrial tephra and hydrothermal fluids could provide new insights into archaeal lineages in the very young biosphere and, possibly, contribute to understanding the nature of the archaeal ancestor of eukaryote organisms (Spang et al, 2015).…”