Navigation Links
Metagenomics of the deep Mediterranean
Date:9/22/2007

Metagenomics is a revolutionary approach to study microbes. Rather than isolating pure cultures, the power of high-throughput sequencing is applied directly to environmental samples to obtain information about the genomes of the prokaryotic cells present in a specific habitat studied. The ocean is an ideal subject of this approach because of its enormous microbiota, whose biomass equals that of all other living organisms on earth is mostly microbial, and also because most of these microbes are extremely fastidious to cultivate.

Craig Venter pioneered these studies and has sampled the surface of the World oceans, but has only scraped the surface. Only one study carried out in Hawaii Ocean Time Series (or HOT) station has analyzed the metagenome of different depths down to 4000m showing the enormous diversity hidden there. This article describes the second study of the bathypelagic region, in this case at a station located over the Ionian abyssal plain, a flat deep basin occupying most of the space between Sicily and Greece in the Eastern Mediterranean. The deep waters of the Mediterranean are special in being free from the intrusion of polar waters that feed most the bottom of the global ocean. The Ionian sample comes from 3000 m deep and is submitted to a continuous pressure of 300 Kg/cm2 but contrastingly to most deep ocean habitats this has a relatively warm temperature of nearly 14C.

In general, a remarkable number of similarities were found with the deep meso-pelagic Pacific and a convergence at the level of taxa found and types of metabolism with the soil microbiota is starting to be perceived. The authors use the term invisible soil paraphrasing the invisible forest coined by Paul Falkowski to refer to the hidden but gigantic primary productivity found in the photic zone. The diversity of metabolic enzymes involved in resilient organic compounds degradation was very high. However, many microbes could complement their heterotrophic metabolism with chemolithotrophic energy supplies and, specifically in the Mediterranean, the oxidation of carbon monoxide, probably released by tectonic activity, could be important. There is also evidence that the microbes rarely live isolated. The free living planktonic lifestyle is probably not very popular in this extremely depleted environment. Quorum sensing genes indicate that instead, microbes tend to aggregate in particles and they could become luminescent maybe to attract and be eaten by animals. This strategy could provide the cells with a sporadic visit to the nutritious oasis of an animal gut. Overall, this paper shows that the deep ocean possesses a rich and mostly unknown microbiota that deserves much more studies.

A recent analysis of a metagenomic library from the deep Mediterranean shows a surprising high number of quorum sensing or lux genes that are only expressed when bacteria live in colonies. The deep ocean might be too depleted in resources for microbes to live independently. Instead the association to detritus particles might give them a rich microenvironment. Now, some of the genes detected have been positively identified as luxA, directly involved in bioluminescence.

Why would deep sea bacteria be luminescent" One possible explanation is that they become attractive to animals that at these depths are very photosensitive. Being swallowed by one of these creatures would give the bacteria a temporary oasis of nutrient-rich conditions before another long dip in the abyssal black.


'/>"/>

Contact: Francisco Rodriguez-Valera
frvalera@umh.es
34-965-919-451
Public Library of Science
Source:Eurekalert

Related biology news :

1. Environmental metagenomics diagnosing extreme environments, tapping opportunities for clean energy
2. Better sludge through metagenomics
3. New science of metagenomics will transform modern microbiology
4. Measuring the impact of post-genomics on Mediterranean populations
5. Phenolic compounds may explain Mediterranean diet benefits
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:5/16/2017)... 16, 2017   Bridge Patient Portal , ... MD EMR Systems , an electronic medical ... GE, have established a partnership to build an ... the GE Centricity™ products, including Centricity Practice Solution ... These new integrations will allow healthcare delivery ...
(Date:4/19/2017)... 19, 2017 The global military ... is marked by the presence of several large global ... by five major players - 3M Cogent, NEC Corporation, ... for nearly 61% of the global military biometric market ... the global military biometrics market boast global presence, which ...
(Date:4/13/2017)... April 13, 2017 UBM,s Advanced Design and ... will feature emerging and evolving technology through its 3D ... will run alongside the expo portion of the event ... and demonstrations focused on trending topics within 3D printing ... and manufacturing event will take place June 13-15, 2017 at ...
Breaking Biology News(10 mins):
(Date:10/12/2017)... ... October 12, 2017 , ... The ... three Winners and six Finalists of the 2017 Blavatnik Regional Awards for Young ... Family Foundation and administered by the New York Academy of Sciences to honor ...
(Date:10/12/2017)... FL (PRWEB) , ... October ... ... (RPS®) today announces publication of a United States multicenter, prospective clinical study ... use, disposable, point-of-care diagnostic test capable of identifying clinically significant acute bacterial ...
(Date:10/12/2017)... ... October 12, 2017 , ... AMRI, a global contract ... to improve patient outcomes and quality of life, will now be offering its ... attributed to new regulatory requirements for all new drug products, including the finalization ...
(Date:10/11/2017)... ... 11, 2017 , ... At its national board meeting in ... Sheikh, the co-founder, CEO and chief research scientist of Minnesota-based Advanced Space Technology ... in ARCS Alumni Hall of Fame . ASTER Labs is a technology ...
Breaking Biology Technology: