Naslov
Diel, Seasonal, and Depth-Related Variability of Viruses and Dissolved DNA in the Northern Adriatic Sea

Autori
Weinbauer, Marcus G. ; Fuks, Dragica ; Puškarić, Staša ; Peduzzi, Peter

Izvornik
Microbial ecology (0095-3628) 30 (1995), 1; 25-41

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Viruses ; dissolved DNA ; dial and seasonal variations ; northern Adriatic Sea

Sažetak
The depth-dependent, seasonal, and diel variability of virus numbers, dissolved DNA (D-DNA), and other microbial parameters was investigated in the northern Adriatic Sea. During periods of water stratification, we found higher virus abundances and virus/bacterium ratios (VBRs) as well as a larger variability of D-DNA concentrations at the thermocline, probably as a result of higher microbial biomass. At the two investigated stations, virus densities were highest in summer and autmn (up to 9.5 x 1010 l-1) and lowest in winter (<109 l-1) ; D-DNA cocentrations were highest in summer and lowest in winter. The VBR as well as an estimated proportion ofviral DNA on total D-DNA showed a strong seasonal variability- VBR averaged 15.0 (range, 0.9-89.1), and the percentage of viral DNA in total D-DNA averaged 18.3% (range, 0.1-96%). An estimation of the percentage of bacteria lysed by viruses, based on 2-hour sample intervals in situ, ranged from 39.6 to 212.2% d-1 in 5 m depth and from 19.9 to 157.2% d-1 in 22 m. The estimated contributionof virus-mediated bacterial DNA release to the D-DNA pool ranged from 32.9 to 161% d-1 in 5 m depth and from 10.3 to 74.2% d-1 in 22 m. Multiple regresion analysis and the diel dynamics of microbial parameters indicate that viral lysis occasionally could be more important in regulation bacterial abundance than grazing by heterotrophic nanoflagellates.

Izvorni jezik
Engleski

Znanstvena područja
Geologija

POVEZANOST RADA