High viral infection rates in Antarctic and Arctic bacterioplankton.
The frequency of visibly phage-infected bacterial cells (FVIB) and the average number of phages per cell [i.e. burst size (BS)] were determined in Antarctic and Arctic ultra-oligotrophic freshwater environments. Water samples were collected from two Antarctic freshwater lakes and cryoconite holes from a glacier in the Arctic. Data from this bipolar study show the highest FVIB (average 26.1%, range 5.1% to 66.7%) and the lowest BS (average 4, range 2-15) ever reported in the literature. The bacterial density is low in these ultra-oligotrophic freshwater environments but a large proportion of the bacteria are visibly infected. Our results suggest that a constant virioplankton population can be maintained in these extreme environments even though host density is low and often slow growing.
Säwström
Christin
C
Climate Impacts Research Centre (CIRC), Department of Ecology and Environmental Science, Umeå University, SE-901 87 Umeå, Sweden. christin.sawstrom@emg.umu.se
Granéli
Wilhelm
W
Laybourn-Parry
Johanna
J
Anesio
Alexandre M
AM
D000864:Antarctic Regions; D001110:Arctic Regions; D001419:Bacteria / Q000648:ultrastructure / Q000821:virology*; D001435:Bacteriophages / Q000502:physiology*; D017753:Ecosystem; D005618:Fresh Water / Q000382:microbiology*; D010933:Plankton / Q000648:ultrastructure / Q000821:virology*