Bacterial Communities of Novaya Zemlya Archipelago Ice and Permafrost

Abstract

The study of bacterial communities associated with extreme ecosystems is one of the most important tasks in modern microbial ecology. Despite a large number of studies being performed, the ecosystems that have not been sufficiently explored from the microbiological point of view still exist. Such research is needed for improving the understanding of the limits and mechanisms of bacterial survival under extreme conditions, and for revealing previously undescribed species and their role in global biospheric processes and their functional specifics. The results of the complex microbiological characteristics of permafrost and ice—collected on the Severniy Island in the northern part of the Novaya Zemlya archipelago—which have not previously been described from microbiological point of view, are presented in this article. The analysis included both culture-independent and culture-dependent methods, in particular, the spectra of metabolic activity range analysis in vitro under different temperature, pH and salinity conditions. High values for the total number of prokaryotes in situ (1.9 × 108–3.5 × 108 cells/g), a significant part of which was able to return to a metabolically active state after thawing, and moderate numbers of culturable bacteria (3.3 × 106–7.8 × 107 CFU/g) were revealed. Representatives of Proteobacteria, Actinobacteria, and Bacteroidetes were dominant in situ; Actinobacteria, Firmicutes, Proteobacteria, and Bacteroidetes were the most abundant phyla in vitro. Physiological assays revealed the mesophilic and neutrophilic optima of temperature and pH of culturing conditions, respectively, and wide temperature and pH ranges of culturable communities’ reproduction activity. Isolated strains were characterized by moderate halotolerant properties and antibiotic resistance, including multiple antibiotic resistance. It was found that almost all cultured bacterial diversity revealed (not just a few resistant species) had extremotolerant properties regarding a number of stress factors. This indicates the high adaptive potential of the studied microbial communities and their high sustainability and capability to retain functional activity under changing environmental (including climatic) conditions in wide ranges.

First report on antibiotic resistance and antimicrobial activity of bacterial isolates from 13,000-year old cave ice core

“…The two XDR Paralcaligenes cave strains SC18B.3 (900-years BP) and SC71.3 (7000-years BP) appeared to have an opposite phenotype as their homologs isolated from soil resistant to only lincomycin, oleandomycin, rifampicin, and vancomycin 85 . Other four XDR cave isolates belonging to Flavobacterium, Paralcaligenes, Phenylobacterium and Microbacterium genera isolated from up to 9000-years old ice (Supplementary Table S1 ) revealed a broader AR than the corresponding species from clinical isolates 86 , but also Antarctic 80 and Arctic 9 , 54 cold habitats.…”

Survival and growth of soil microbial communities under influence of sodium perchlorates

“…To elucidate the mechanism of perchlorate action on microorganisms in soils, it is necessary to carry out parallel incubation and analysis of samples both in the presence of perchlorate and in the presence of other salts, for example, chlorides, which do not possess the properties of strong oxidizers. It is shown that about 30–70% of culturable heterotrophic aerobic bacteria isolated from arid soils and permafrosts are able to grow in media containing 5% NaCl (Belov et al ., 2018, 2019, 2020 a , 2020 b ). It is known that sodium chloride at concentrations ~5% inhibit microbial growth (in terms of [ 3 H]-leucine incorporation into biomass) and respiration in soils at 2–3 times (Wichern et al ., 2006; Rousk et al ., 2011; Rath et al ., 2016).…”

“…This concentration is not the limit at which the survival of certain microorganisms is indicated. However, this concentration can inhibit the growth and metabolic activity of microorganisms and lead to their death (Matsubara et al ., 2017; Beblo-Vranesevic et al ., 2017 b ; Belov et al ., 2018, 2019, 2020 a , 2020 b ). Thereby, the discovery of such a high tolerance of soil microbial communities is somewhat unexpected.…”

“…In communities existing under conditions of moisture deficiency and extreme temperatures, resistance mechanisms should be well developed (Fierer et al ., 2012; Goordial et al ., 2017). The results are consistent with the previously shown high radioresistance of the microbial communities of the studied samples (Cheptsov et al ., 2018 b , 2018 c , 2018d), as well as with information regarding the high per cent of perchlorate-tolerant bacteria in microbial communities of desert soils and permafrost (Belov et al ., 2018, 2019, 2020 a , 2020 b ).…”

“…Fifty-two per cent of aerobic heterotrophic bacteria isolated from these samples reproduced on a medium containing 5% Mg(ClO 4 ) 2 . The most tolerant strains belonged to genera Agrococcus , Arthrobacter , Bacillus , Brachybacterium , Cellulomonas , Georgenia , Kocuria , Leucobacter , Massilia , Microbacterium , Planomicrobium , Plantibacter , Pontibacter , Pseudarthrobacter , Pseudochrobactrum , Pseudomonas , Rhodococcus , Rufibacter , Salinibacterium , Sphingomonas , Streptomyces (Belov et al ., 2018, 2019, 2020 a , 2020 b ).…”