Bacteriophages in Arctic and Antarctic low-temperature systems

Abstract

Comparative analysis of the presence of bacteriophages was carried out for the water column of a permanently ice-covered, extremely oligotrophic Lake Untersee (East Antarctica) and the ancient ice wedge of the Mamontova Gora outcrop (Aldan River, Central Yakutia). Microscopy revealed bacteriophages in the Mamontova Gora ice samples and in the lysates of the pure cultures of phage-sensitive bacteria isolated from the same samples. Bacteriophages isolated from these cultures were filamentous and interacted with bacteria as moderate (lysogenic) phages. A similar filamentous bacteriophage was isolated from the Lake Untersee water column. The highest morphological diversity of bacteriophages was revealed by microscopy in the oxic Lake Untersee water column in the chemocline zone (70-76 m) and in the sulfide layer (85 m). Detection of similar filamentous bacteriophages in a relic ice sample and in the samples from Antarctic Lake Untersee indicate wide occurrence of bacteriophages and lysogeny in microbial communities of low-temperature ecosystems.

Host-Associated Phages Disperse across the Extraterrestrial Analogue Antarctica

“…Some Ralstonia phages occur as non-integrative, episomal forms, e.g., RS603, a hybrid of RSM1/3 infecting the phytopathogen R. solanacearum (49), whose genome lacks a resolvase domain (Figure 2A), but many mesophilic Ralstonia also occur as lysogens (50). Lysogeny, a lifestyle during which the phage genome becomes integrated into the host chromosome, is a widespread phenomenon in low temperature environments (51)(52)(53) and likely attributed to prolonged starvation and low activity of host cells under harsh conditions, the latter being previously reported for Ralstonia (15). Since p12D and its counterpart from the WAP have a resolvase-domain containing protein likely functioning in integration/excision during lysogenisation (54,55), we conclude that they must be temperate phages of Ralstonia.…”

Metagenomic Characterization of Resistance Genes in Deception Island and Their Association with Mobile Genetic Elements

“…The importance of phages as ARGs carriers in different environments has been described previously [ 55 , 56 , 57 , 58 , 59 ]. In addition, the importance of phages in the evolution and adaptation of bacterial communities in Antarctica has been described [ 60 , 61 ]. Van Goethem et al, 2018 [ 3 ] described that the mobile elements would have a low incidence in the dissemination of ARGs.…”

Host-associated phages disperse across the extraterrestrial analogue Antarctica

“…Lysogeny, a lifestyle during which the phage genome becomes integrated into the host chromosome, is a widespread phenomenon in low temperature environments (53)(54)(55) and likely attributed to prolonged starvation and low activity of host cells under harsh conditions.…”

“…Dispersal of Antarctic phage 20 Some Ralstonia phages occur as non-integrative, episomal forms, e.g., RS603, a hybrid of RSM1/3 infecting the phytopathogen R. solanacearum (49), whose genome lacks a resolvase domain (Figure 2A), but many mesophilic Ralstonia also occur as lysogens (50). Lysogeny, a lifestyle during which the phage genome becomes integrated into the host chromosome, is a widespread phenomenon in low temperature environments (51)(52)(53) and likely attributed to prolonged starvation and low activity of host cells under harsh conditions, the latter being previously reported for Ralstonia (15). Since p12D and its counterpart from the WAP have a resolvase-domain containing protein likely functioning in integration/excision during lysogenisation (54,55), we conclude that they must be temperate phages of Ralstonia.…”