Effects of UV radiation on the chlorophyte Micromonas polaris host–virus interactions and MpoV-45T virus infectivity

• Published in: Microorganisms
• Main Authors: Eich, C., Pont, S.B.E.H., Brussaard, C.P.D.
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2021
• Subjects: Micromonas polaris; Arctic; Phytoplankton
• Online Access: https://www.vliz.be/imisdocs/publications/99/369899.pdf

Polar seas are under threat of enhanced UV-radiation as well as increasing shipping activities. Considering the ecological importance of marine viruses, it is timely to study the impact of UV-AB on Arctic phytoplankton host–virus interactions and also test the efficacy of ballast water (BW) UV-C treatment on virus infectivity. This study examined the effects of:(i) ecologically relevant doses of UV-AB radiation on Micromonas polaris RCC2258 and its virus MpoV-45T, and (ii) UV-C radiation (doses 25–800 mJ cm −2 ) on MpoV-45T and other temperate algal viruses. Total UV-AB exposure was 6, 12, 28 and 48 h (during the light periods, over 72 h total). Strongest reduction in algal growth and photosynthetic efficiency occurred for 28 and 48 h UV-AB treatments, and consequently the virus production rates and burst sizes were reduced by more than half (compared with PAR-only controls). For the shorter UV-AB exposed cultures, negative effects by UV (especially Fv/Fm) were overcomewithout impacting virus proliferation. To obtain the BW desired log −4 reduction in virus infectivity, a UV-C dose of at least 400 mJ cm −2 was needed for MpoV-45T and the temperate algal viruses. This is higher than the commonly used dose of 300 mJ cm −2 in BW treatment. View Full-Text