Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Predatory organisms at depth

21.01.2014
Viruses within the ocean floor comprise the greatest fraction of the deep biosphere


In the current issue of the Journal of the International Society for Microbial Ecology (ISME Journal, 20.1.2014) scientists from the University of Oldenburg and from the GFZ German Centre for Geosciences show that in deep, old and nutrient-poor marine sediments there are up to 225 times more viruses than microbes.

In such extreme habitats viruses make up the largest fraction of living biomass and take over the role as predators in this bizarre ecosystem.

The scientists found that with decreasing nutrient levels the ratio between viruses and cells shifts more toward viruses.

“For several years it has been know that the biomass of all microbes within the sea floor equals that of all life in the oceans above” reports Jens Kallmeyer from the GFZ. “Viruses, however, have been neglected previously”.

In these extreme environments viruses take over the role of predatory organisms: They control size and composition of the microbial community. The surprisingly high number of viruses can be explained by the fact that the small but active microbial community permanently produces new viruses that remain in the sediment for longer times because the few microbes produce fewer enzymes that can destroy viruses.

Previous measurements in seawater and surficial sediments showed that viruses are about ten times more abundant than microbes, but because of their much smaller biomass they did not play a major role in estimates of the total living biomass. Moreover, it was assumed that predators such as unicellular organisms, but also worms and snails control the size of the microbial population. The new results show that these simple assumptions are no longer valid.

Engelhardt, T., Kallmeyer, J., Cypionka, H., & Engelen, B. (2014): „High virus-to-cell ratios indicate ongoing production of viruses in deep subsurface sediments”, ISME Journal. doi: 10.1038/ismej.2013.245; 20.01.2014

Franz Ossing | GFZ Potsdam
Further information:
http://www.gfz-potsdam.de/

More articles from Life Sciences:

nachricht Blowfly maggots provide physical evidence for forensic cases
02.09.2014 | Universiti Teknologi MARA (UiTM)

nachricht Surprising new role for calcium in sensing pain
02.09.2014 | Duke University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Anzeige

Anzeige

Event News

IT security in the digital society

27.08.2014 | Event News

Understanding the brain—neuroscientists meet in Göttingen

27.08.2014 | Event News

MEDICA EDUCATION CONFERENCE: Bessere Behandlung dank Biomarker

21.08.2014 | Event News

 
Latest News

A smart fluorescent antenna for Wi-Fi applications

02.09.2014 | Power and Electrical Engineering

Blowfly maggots provide physical evidence for forensic cases

02.09.2014 | Life Sciences

Single laser stops molecular tumbling motion instantly

02.09.2014 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>