摘要
Viral abundance, burst sizes, lytic production and temperate phage were investigated in land-fast ice at two sites in Prydz Bay Antarctica (68掳S, 77掳E) between April and November 2008. Both ice cores and brine were collected. There was no seasonal pattern in viral or bacterial numbers. Across the two sites virus abundances ranged between 0.5 脳 105 and 5.1 脳 105 viruses ml−1 in melted ice cores and 0.6 脳 1058211;3.5 脳 105 viruses ml−1 in brine, and bacterial abundances between 2.7 脳 104 and 17.3 脳 104 cells ml−1 in melted ice cores and 3.9 脳 1048211;32.5 脳 104 cells ml−1 in brine. Virus to bacterium ratios (VBR) showed a clear seasonal pattern in ice cores with lowest values in winter (range 1.28211;20.8), while VBRs in brine were lower (0.28211;4.9). Lytic viral production range from undetectable to 2.0 脳 104 viruses ml−1 h−1 in ice cores with maximum rates in September and November. In brine maximum, lytic viral production occurred in November (1.18 脳 104 viruses ml−1 h−1). Low burst sizes were typical (3.948211;4.03 viruses per bacterium in ice cores and 3.168211;4.0 viruses per bacterium in brine) with unusually high levels of visibly infected cells—range 408211;50%. This long-term investigation revealed that viral activity was apparent within the sea ice throughout its annual cycle. The findings are discussed within the context of limited data available on viruses in sea ice.