Cold‐active bacteriophages from the Baltic Sea ice have diverse genomes and virus–host interactions

• Published in: Environmental Microbiology
• Main Authors: Senčilo, Ana, Luhtanen, Anne‐Mari, Saarijärvi, Mikko, Bamford, Dennis H., Roine, Elina
• Other Authors: Academy of Finland, Walter and Andrée de Nottbeck Foundation, University of Helsinki
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2014
• Subjects: Sea ice
• Online Access: http://dx.doi.org/10.1111/1462-2920.12611; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2F1462-2920.12611; http://onlinelibrary.wiley.com/wol1/doi/10.1111/1462-2920.12611/fullpdf

Summary Heterotrophic bacteria are the major prokaryotic component of the B altic S ea ice microbiome, and it is postulated that phages are among their major parasites. In this study, we sequenced the complete genomes of six earlier reported phage isolates from the B altic S ea ice infecting S hewanella sp. and F lavobacterium sp. hosts as well as characterized the phage–host interactions. Based on the genome sequences, the six phages were classified into five new genera. Only two phages, 1/4 and 1/40, both infecting S hewanella sp. strains, showed significant nucleotide sequence similarity to each other and could be grouped into the same genus. These two phages are also related to V ibrio ‐specific phages sharing approximately 25% of the predicted gene products. Nevertheless, cross‐titrations showed that the cold‐active phages studied are host specific: none of the seven additionally tested, closely related S hewanella strains served as hosts for the phages. Adsorption experiments of two S hewanella phages, 1/4 and 3/49, conducted at 4° C and at 15° C revealed relatively fast adsorption rates that are, for example, comparable with those of phages infective in mesophilic conditions. Despite the small number of S hewanella phages characterized here, we could already find different types of phage–host interactions including a putative abortive infection.