Viral infection plays a key role in extracellular DNA dynamics in marine anoxic systems

  title={Viral infection plays a key role in extracellular DNA dynamics in marine anoxic systems},
  author={Cinzia Corinaldesi and Antonio Dell'Anno and Roberto Danovaro},
  journal={Limnology and Oceanography},
To investigate the role of viruses in extracellular DNA production through cell lysis, we selected two systems where viruses are expected to be the main component controlling prokaryote dynamics. These systems include anoxic subsuperficial coastal sediments and water and sediments of two deep‐hypersaline anoxic basins (i.e., DHABs) of the eastern Mediterranean. Viral production was high in both places. Viruses were responsible for 10–60% of prokaryote mortality in anoxic sediments and up to 100… 

Extracellular DNA can preserve the genetic signatures of present and past viral infection events in deep hypersaline anoxic basins

It is found that DHAB sediments are hot-spots of viral infections, which largely contribute to the release of high amounts of extracellular DNA, suggesting that extrace cellular DNA released from killed prokaryotes can be the most suitable trophic resource for benthic proKaryotes.

Viral Induced Microbial Mortality in Arctic Hypersaline Spring Sediments

The findings indicate that viruses in low-energy systems maintain low rates of production and activity, have a small but notable impact on microbial mortality (8–29% attenuation of growth) and that successful viral replication may primarily proceed by non-lethal strategies.

Major viral impact on the functioning of benthic deep-sea ecosystems

It is reported that viral production in deep-sea benthic ecosystems worldwide is extremely high, and that viral infections are responsible for the abatement of 80% of prokaryotic heterotrophic production.

Origin, dynamics, and implications of extracellular DNA pools in marine sediments.

Early diagenesis and trophic role of extracellular DNA in different benthic ecosystems

The data suggest that bioavailable extracellular DNA might represent an important nutrient source for benthic heterotrophic metabolism and open new perspectives for a better understanding of the factors that influence the functioning of benthics systems.

Determination of viral production in aquatic sediments using the dilution-based approach

The method presented in this protocol relies on the short-time incubations of sediment samples with virus-free seawater, and the subsequent determination of the increase in viral abundance over time by epifluorescence microscopy, and is highly reliable, inexpensive and easy to use.

Viruses and prokaryotes in the deep-sea

This work has shown that microbes dominates both in terms of abundance and biomass the world oceans and that viruses are the most abundant biological entities of the biosphere, suggesting that viruses can account for the vast majority of the genetic diversity of the Earth.

Viral infections stimulate the metabolism and shape prokaryotic assemblages in submarine mud volcanoes

The findings highlight the significant role of the viral shunt in sustaining the metabolism of prokaryotes and shaping their assemblage structure in mud volcano sediments, and they provide new clues for the understanding of the functioning of cold-seep ecosystems.

Viriobenthos in aquatic sediments: variability in abundance and production and impact on the C-cycle

The dynamics of viruses infecting prokaryotes appeared linked to proKaryotic metabolism, supporting the hypothesis that benthic viruses originate directly in the sediment as a result of infection events rather than sinking from the water column.

Enhanced viral activity and dark CO2 fixation rates under oxygen depletion: the case study of the marine Lake Rogoznica.

It is suggested that the expansion of low-oxygen zones can trigger higher viral impacts on prokaryotic heterotrophic and chemoautotrophic metabolism, with cascading effects, neglected so far, on biogeochemical processes.



Dynamics of extracellular DNA in the marine environment

Actively growing heterotrophic bacterioplankton were found to produce dissolved DNA, presumably through the processes of death and lysis, grazing by bacteriovores, and excretion, and played a key role in the cycling of this material.

Lysogeny and virus‐induced mortality of bacterioplankton in surface, deep, and anoxic marine waters

Across all investigated environments, FLC was negatively related to bacterial abundance and production, whereas FIC showed a positive relationship with viral and bacterial parameters, indicating that environments exist where one of the two viral life strategies prevails.

Extracellular DNA in aquatic ecosystems may in part be due to phycovirus activity

In a eutrophic lake, a crash of the algal population was followed by a significant increase in the number of virus-like particles, and soon thereafter by an increase of the amount of extracellular DNA.

Viruses, prokaryotes and DNA in the sediments of a deep-hypersaline anoxic basin (DHAB) of the Mediterranean Sea.

The analysis of vertical profiles of viral abundance revealed the lack of significant changes with depth in the sediment, suggesting that benthic viruses in these anoxic and hypersaline conditions are preserved or resistant to decay.

Distribution of Viruses and Dissolved DNA along a Coastal Trophic Gradient in the Northern Adriatic Sea

The distribution of viral and other microbial abundances as well as the concentrations of dissolved DNA along a trophic gradient in the northern Adriatic Sea were determined and some kind of interaction between heterotrophic nanoflagellates and viruses is proposed, concluding that viral activity may play a significant role in food web structure under changing trophIC conditions.

Virus production and life strategies in aquatic sediments

The results suggest that high benthic virus production rates can have a significant effect on bentho-benthic bacterial dynamics and indicate that virus production should be included in biogeochemical models of aquatic sediments.

Viral lysis of bacteria: an important source of dissolved amino acids and cell wall compounds

  • M. MiddelboeN. Jørgensen
  • Environmental Science, Biology
    Journal of the Marine Biological Association of the United Kingdom
  • 2006
It is suggested that virus-mediated DOM is a source of a variety of organic compounds, which contribute significantly to the pool of rapidly recycling material in the ocean.

Virus and bacteria dynamics of a coastal sediment: Implication for benthic carbon cycling

These measurements support the general observation that virus abundance and production correlate with the trophic status of the environment and show that microbial activity can regulate the viriobenthic production in undiluted, homogenized marine sediments.

Significance of Viral Lysis and Flagellate Grazing as Factors Controlling Bacterioplankton Production in a Eutrophic Lake

The high mortality of bacterioplankton due to viral lysis in anoxic water indicates that a significant portion of bacterial production in the metalimnion and hypolimnions is cycled in the bacterium-virus-DOM loop, which has major implications for the fate and cycling of organic nutrients in lakes.

Virioplankton: Viruses in Aquatic Ecosystems

Novel applications of molecular genetic techniques have provided good evidence that viral infection can significantly influence the composition and diversity of aquatic microbial communities, supporting the hypothesis that viruses play a significant role in microbial food webs.