Extremely high UV-C radiation resistant microorganisms from desert environments with different manganese concentrations

The Hyperarid Core of the Atacama Desert, an Extremely Dry and Carbon Deprived Habitat of Potential Interest for the Field of Carbon Science

“…As mentioned before, several species of microorganisms highly tolerant to UV radiation have been found in the hyperarid core of the Atacama (Paulino-Lima et al, 2013, 2016), and may be assumed that most of the organic compounds of such species should persist for a longer time in these soils. If so, the organic compounds found in these hyperarid soils should mainly come from native microorganisms, also supporting hypothesis N2.…”

“…Pertaining the effects of the UV radiation, there are several reports on the level of tolerance by different species of microorganisms to UV radiation, both native of the Atacama and also introduced as models (Cockell et al, 2008; Paulino-Lima et al, 2013, 2016). However, there are no reports on how specific organic molecules degrade in time when exposed to the daily fluxes of UV radiation typical the hyperarid core of the Atacama.…”

“…Although the current interest of the scientific community is to understand how these microorganisms are able to tolerant the extreme desiccation and high UV radiation conditions of the Atacama (Wierzchos et al, 2006; Azua-Bustos et al, 2009, 2010, 2011; Paulino-Lima et al, 2016), nothing has yet been reported on how heterotrophic species are able to obtain, mobilize and use organic carbon in a place where carbon and water are virtually absent. In this short hypothesis paper, we review the reports up to date on organic carbon concentrations in soils of the Atacama, proposing that due to the meager amounts of organic carbon and extremely dry conditions, the microbial communities of the hyperarid core of the Atacama Desert may be of interest for the field of carbon science (for a review on the biodiversity of heterotrophic microbial species reported in the hyperarid core of the Atacama see Azua-Bustos et al, 2012a,b).…”

Nitrates as a Potential N Supply for Microbial Ecosystems in a Hyperarid Mars Analog System

“…Atacama soils are generally assumed to be C-limited with very slow carbon cycling [75], because of low organic C/N ratios. Phylogenetically ancient eukaryotes related to red algae [76,77], microbial biofilms [78], and specifically UV-resistant microorganisms [79,80] are also found to be present in the Atacama Desert, and could provide a persistent source of organic carbon for heterotrophy [81]. However, microbial C mineralization remains at low levels even with episodically enhanced moisture input associated with rainfall events [55,82].…”

Radiation as a Constraint for Life in the Universe

“…In haloarchaea, high intracellular concentrations of KCl seem to also provide protection against radiation through interaction with free radicals (Kish et al, 2009). Other radio-resistant microorganisms such as D. radiodurans showed that high intracellular Mn/Fe ratio combined with desiccation contributes to ionizing radiation resistance (Paulino-Lima et al, 2016). Also, physiological mechanisms such as polyploidy present in haloarchaea seem to provide advantages against radiation damage (Breuert et al, 2006).…”