Microbial diversity of an Antarctic subglacial community and high‐resolution replicate sampling inform hydrological connectivity in a polar desert

Abstract

Summary Antarctic subglacial environments host microbial ecosystems and are proving to be geochemically and biologically diverse. The Taylor Glacier, Antarctica, periodically expels iron‐rich brine through a conduit sourced from a deep subglacial aquifer, creating a dramatic red surface feature known as Blood Falls. We used Illumina MiSeq sequencing to describe the core microbiome of this subglacial brine and identified previously undetected but abundant groups including the candidate bacterial phylum Atribacteria and archaeal phylum Pacearchaeota. Our work represents the first microbial characterization of samples collected from within a glacier using a melt probe, and the only Antarctic subglacial aquatic environment that, to date, has been sampled twice. A comparative analysis showed the brine community to be stable at the operational taxonomic unit level of 99% identity over a decade. Higher resolution sequencing enabled deconvolution of the microbiome of subglacial brine from mixtures of materials collected at the glacier surface. Diversity patterns between this brine and samples from the surrounding landscape provide insight into the hydrological connectivity of subglacial fluids to the surface polar desert environment. Understanding subice brines collected on the surfaces of thick ice covers has implications for analyses of expelled materials that may be sampled on icy extraterrestrial worlds.

Distinctive microbial communities in subzero hypersaline brines from Arctic coastal sea ice and rarely sampled cryopegs

“…Marinobacter is also abundant in Blood Falls, the saline subglacial outflow from Taylor Glacier, Antarctica (Mikucki and Priscu 2007; Campen et al . 2019). Cultivation studies have yielded isolates of Marinobacter from both the cold spring system on Axel Heiberg Island (Niederberger et al .…”

Evidence for Pathways of Concentrated Submarine Groundwater Discharge in East Antarctica from Helicopter-Borne Electrical Resistivity Measurements

“…Geochemistry of brine collected at Blood Falls suggests cryoconentrated seawater with modification from rock-water interaction and evaporation [25,26,38,40]. The brine from Blood Falls also hosts a metabolically active [25] and diverse microbial community that is distinct from the surrounding glacier ice [41]. Together with the extended rock-water interactions, the metabolic activity of microorganisms can facilitate mineral weathering in the subsurface, leading to high solute loads in some groundwaters.…”

Key Technologies and Instrumentation for Subsurface Exploration of Ocean Worlds

“…An IceMole with advanced navigation capabilities was build for the DLR-funded Enceladus Explorer (EnEx) project (Konstantinidis et al 2014). After tests on alpine glaciers, this EnEx-IceMole Kowalski et al 2016)) was used for the successful clean sampling of brine from an englacial reservoir at Blood Falls, Antarctica Campen et al 2019),…”