The first known virus isolates from Antarctic sea ice have complex infection patterns

• Published in: FEMS Microbiology Ecology
• Main Authors: Luhtanen, A.-M., Eronen-Rasimus, E., Oksanen, H.M., Tison, J.-L., Delille, B., Dieckmann, G.S., Rintala, J.-M., Bamford, D.H.
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2018
• Subjects: Antarctic; Weddell; Weddell Sea; Antarc*; Antarctica; Sea ice
• Online Access: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=301262

Viruses are recognized as important actors in ocean ecology and biogeochemical cycles, but many details are not yet understood. We participated in a winter expedition to the Weddell Sea, Antarctica, to isolate viruses and to measure virus-like particle abundance (flow cytometry) in sea ice. We isolated 59 bacterial strains and the first four Antarctic sea-ice viruses known (PANV1, PANV2, OANV1 and OANV2), which grow in bacterial hosts belonging to the typical sea-ice genera Paraglaciecola and Octadecabacter . The viruses were specific for bacteria at the strain level, although OANV1 was able to infect strains from two different classes. Both PANV1 and PANV2 infected 11/15 isolated Paraglaciecola strains that had almost identical 16S rRNA gene sequences, but the plating efficiencies differed among the strains, whereas OANV1 infected 3/7 Octadecabacter and 1/15 Paraglaciecola strains and OANV2 1/7 Octadecabacter strains. All the phages were cold-active and able to infect their original host at 0°C and 4°C, but not at higher temperatures. The results showed that virus–host interactions can be very complex and that the viral community can also be dynamic in the winter-sea ice.