Photoreactivation compensates for UV damage and restores infectivity to natural marine virus communities

Abstract

We investigated the potential for photoreactivation to restore infectivity to sunlight-damaged natural viral communities in offshore (chlorophyll a, <0.1 g liter ؊1), coastal (chlorophyll a, ca. 0.2 g liter ؊1), and estuarine (chlorophyll a, ca. 1 to 5 g liter ؊1) waters of the Gulf of Mexico. In 67% of samples, the lightdependent repair mechanisms of the bacterium Vibrio natriegens restored infectivity to natural viral communities which could not be repaired by light-independent mechanisms. Similarly, exposure of sunlight-damaged natural viral communities to >312-nm-wavelength sunlight in the presence of the natural bacterial communities restored infectivity to 21 to 26% of sunlight-damaged viruses in oceanic waters and 41 to 52% of the damaged viruses in coastal and estuarine waters. Wavelengths between 370 and 550 nm were responsible for restoring infectivity to the damaged viruses. These results indicate that light-dependent repair, probably photoreactivation, compensated for a large fraction of sunlight-induced DNA damage in natural viral communities and is potentially essential for the maintenance of high concentrations of viruses in surface waters.

Distribution of microbial populations and their relationship with environmental parameters in the coastal waters of Qingdao, China

“…Our results revealed that viral abundance was also correlated with nanophytoplankton abundance, as well as with the depth and concentration of dissolved oxygen, which supports the hypothesis that viral abundance could also be influenced by environmental parameters (Guixaboixareu et al, 1996;Wommack et al, 1996;Noble and Fuhrman, 1997;Weinbauer et al, 1997;Jacquet and Bratbak, 2003;Clasen et al, 2008). However, Corinaldesi and colleagues (2003) reported that within large spatial scales, viral abundance was only dependent on bacterial activity and host cell abundance in highly eutrophic systems.…”

Effects of ultraviolet radiation on marine virus–phytoplankton interactions

“…Noble and Fuhrman [32] also observed that low levels of UVA contributed very little to the loss of infectivity of bacteriophages in contrast to UVB. This may be due to the relatively low UVA intensity applied in these experiments since it is known that UVA is involved in the recovery processes of some viruses [36,40]. A possible e¡ect may also have escaped our attention as we did not measure viral infectivity directly.…”

Factors affecting virus dynamics and microbial host-virus interactions in marine environments

“…The combined activities of these repair systems should enhance survival and maintenance of viral activity, particularly in the relatively UV-rich surface waters. While some large dsDNA algal viruses may encode for their own DNA repair enzymes, most viruses rely on repair mechanisms of their hosts, which are achievable only after DNA has been inserted into the host cell (Furuta et al, 1997;Weinbauer et al, 1997;Shaffer et al, 1999;Orgata et al, 2011;Santini et al, 2013). In the summer, Garza & Suttle (1998) found twofold lower decay rates of natural cyanophage communities as compared to isolates, whereas in the winter, they were equal, suggesting (seasonal) selection for viruses that encoding host-mediated repair mechanisms.…”