Elevational Constraints on the Composition and Genomic Attributes of Microbial Communities in Antarctic Soils

Abstract

Antarctic soils represent an ideal system to study how environmental properties shape the taxonomic and functional diversity of microbial communities given the relatively low diversity of Antarctic soil microbial communities and the pronounced environmental gradients that occur across soils located in reasonable proximity to one another. Moreover, the challenging environmental conditions typical of most Antarctic soils present an opportunity to investigate the traits that allow soil microbes to persist in some of the most inhospitable habitats on Earth.

Prevalence of trace gas-oxidizing soil bacteria increases with radial distance from Polloquere hot spring within a high-elevation Andean cold desert

“…A more recently characterized hydrogenase, subgroup 1l, also appeared as the second most abundant Group 1 hydrogenase in the distal soils of PQ2 and PQ3. This group has also been found to mediate high-affinity H 2 oxidation and is particularly common in Antarctic desert soils [ 13 , 14 , 20 ]. The increased abundance of 1h and 1l hydrogenases with increasing distance corroborates the observed increase in atmospheric H 2 uptake by these soils.…”

“…The biological oxidation of trace gases is vital to biogeochemical cycles [ 15 ] and represents a significant sink of atmospheric gas that is increasingly considered in global models [ 16–18 ]. Experimental and genomic evidence of trace gas-oxidizing bacteria has been shown in diverse arid environments, including polar Arctic/Antarctic soils [ 10 , 11 , 13 , 14 , 19 , 20 ] and hot deserts [ 8 , 9 , 12 , 21 , 22 ]. It is hypothesized that trace gas metabolisms are a survival mechanism for maintaining cellular function in these oligotrophic environments with scarce substrates and under conditions where alternative metabolisms may not be functional [ 23 , 24 ].…”

The Early Microbial Colonizers of a Short-Lived Volcanic Island in the Kingdom of Tonga

“…More specifically, we identified genes for the catalytic subunits of group 1 ( NiFe ) hydrogenases, group 2 ( NiFe ) hydrogenases, and form 1 carbon monoxide (CO) dehydrogenases ( CoxL ) ( 67 ). Atmospheric H 2 and CO oxidation are common strategies used by bacteria to sustain metabolic activity in resource-limited environments because these compounds are ubiquitous in the troposphere ( 68 , 69 ). Organisms that use trace gas metabolism to sustain growth have been well described in Antarctic soils and other resource-limited systems ( 35 , 68 – 70 ).…”

“…Atmospheric H 2 and CO oxidation are common strategies used by bacteria to sustain metabolic activity in resource-limited environments because these compounds are ubiquitous in the troposphere ( 68 , 69 ). Organisms that use trace gas metabolism to sustain growth have been well described in Antarctic soils and other resource-limited systems ( 35 , 68 – 70 ). While we acknowledge that the presence of genes does not necessarily indicate that these metabolisms are occurring in situ , such metabolic processes have been confirmed in recent volcanic ejecta ( 10 ).…”

Islands in the ice: Potential impacts of habitat transformation on Antarctic biodiversity

“…Other abiotic factors influencing the ecological functionality of new ice-free habitats are the properties of newly exposed soils, including pH, salinity, and levels of organic matter and nutrients, which will determine initial habitat suitability for vegetation, microfauna, and microbes (Barrett et al, 2006;Courtright et al, 2001;Dragone et al, 2022;Smykla et al, 2018). Multiple environmental and geographical factors determine these soil properties, including elevation, temperature, age of the soil, distance to coast, distance to the nearest vertebrate colony, and geological-, glacial-, and sealevel history (Adamson & Pickard, 1986;Diaz et al, 2021;Dragone et al, 2022;Franco et al, 2021;Smykla et al, 2007). Because many Antarctic soils are nutrient poor, breeding seabird colonies have a large influence on terrestrial communities around coastal Antarctica, where nitrogen-rich guano provides essential nutrients for biodiversity (Bokhorst et al, 2019;Casanovas et al, 2015;Smykla et al, 2007Smykla et al, , 2015.…”