Viruses in bottom sediments in a eutrophic reservoir (Ivankovo Reservoir, Upper Volga)
- 30 Downloads
The total number of viruses, morphological and size composition of viriobenthos, number of bacterial cells infected by viruses, number of mature phages inside bacterial cells, and virus-induced mortality of bacteriobenthos have been estimated in bottom sediments of the Ivankovo Reservoir. The total number of viriobenthos in the reservoir range from 10.3 to 83.2 (31.5 ± 6.2 on average) billion particles/cm3. The total number of virus-to-bacteria ratio in the Ivan’kovo reservoir varies between 0.3 and 1.7 (0.7 ± 0.1 on average). A positive correlation between viral and bacterial abundance is found (R = 0.61, p = 0.05). In different parts of the reservoir, viral infection of bacteria is not observed or is very low. The number of infected bacteria ranges from 1.0 to 3.5% (1.7 ± 0.2% on average) of the total viriobenthos abundance and mortality due to viral lysis accounts for 1.0–3.7% (1.8 ± 0.2% on average) of the total bacterial mortality. The number of phages found inside bacterial cells average 8 ± 1 phages/cell. Thus, a phenomenon known as “infection paradox” is observed in the Ivankovo Reservoir when, at a very high viral abundance, no viral infection of bacteria is recorded or it was very low.
Keywordsviriobenthos bacteria infected by viruses virus-induced mortality of bacteriobenthos reservoir
Unable to display preview. Download preview PDF.
- 12.Maranger, R. and Bird, D.F., High concentrations of viruses in the sediments of Lac Gilbert, Quebec, Microb. Ecol., 1996, Vol. 31, pp. 141–151.Google Scholar
- 19.Simek, K., Pernthaler, I., Weinbauer, M.G., et al., Changes in bacterial community composition dynamics and viral mortality rates associated with enhanced flagellate grazing in a mesoeutrophic reservoir, Appl. Environ. Microbiol., 2001, Vol. 67, No. 6, pp. 2723–2733.PubMedCentralCrossRefPubMedGoogle Scholar
- 20.Slovâcková, H., Study of the ecological role of viruses and bacteria in aquatic ecosystems, Dis. Thes., Brno, 2008.Google Scholar