Virus ... at the bottom of the Sea
By Lionel Perez Valenzuela
is not the title of a horror novel or science fiction, but the result of a Research conducted by the Polytechnic University of Marche in Italy and published in the journal Nature.
has always struck the seabed rich in organic matter, so keep a few animals. It was known that such an abundance of carbon and nutrients, could have a huge amount of heterotrophic bacteria, which in turn could be the food of other organisms such as protozoan, worms, filter and other animals.
This organic matter and decomposing-fermenting bacteria could maintain a complete ecosystem, with an abundant flow of matter and energy. However, none of this happens, and nutrients and carbon are trapped on the ocean floor. A real paradox.
Why seabed worldwide there are no agencies greater than a microbe?
The answer may lie in the bacteriophages.
The bacteriophages, viruses bacteria were discovered in 1917 by French-Canadian researcher Felix d'Herelle (inventor of phage therapy and a remarkable life that I recommend to know). D'Herelle
noted that an invisible agent was destroying their crops of dysentery bacilli (bacteria that cause dysentery). The agent passed through filters that retained bacteria and only multiplied in the presence of live bacteria, causing them to swell and lyse.
remember that there are two basic types bacteriophage, lytic viruses (lytic cycle do) and lysogenic viruses or tempered (made lysogenic).
lytic viruses infecting bacteria, viral genes taking control of bacterial metabolism, and quickly produce new viral proteins and new viral genome copies. The viral proteins self-assemble to form capsids with their respective viral genome. Finally there is lysis of the host bacteria (destruction of bacteria).
lysogenic In the temperate phage that infects bacteria and is integrated into the bacterial genome, replicated viral DNA with bacterial DNA. Bacteriophage could also be stable as plasmid, not integrated. Thus the temperate phage-infected bacteria can carry the virus's genetic information over multiple generations, without releasing phage abroad (this cycle was discovered by André Lwoff). The phage is "latent" until it can be reactivated under certain conditions (eg if the bacteria's DNA is damaged, for lack of nutrients, temperature changes, UV rays, chemical mutagens, etc.).. Once reactivated phage, begin to multiply which will lead to bacterial lysis.
bacteriophages in some cases give new properties to bacteria while they remain in the lysogenic state, a phenomenon known as lysogenic conversion . The best known case is that of the cholera vibrio (Vibrio cholerae), responsible for cholera epidemics. Strains of this bacteria can be harmless can become highly pathogenic by lysogenic conversion, ie by the action of a phage.
Only in 1939, Helmut Ruska, bacteriophages observed by electron microscopy. Remembered for the lunar module structure, and how fixing bacteria.
The top micrograph obtained with a microscope e can see a bacterium surrounded by dozens of bacteriophages have already joined.
Virus in the sea and seabed.
relatively recently discovered the INMESA amount of phages that exist in the sea, there may be billions of phage and other viruses per milliliter of sea water, and 70% of marine bacteria to be infected.
This brings us back to the sea, more precisely in the background. Samples collected from different parts of the world Roberto Danovaro of Italy's University of Marche, found that one gram of marine sediment has one billion virus particles. This result remained in sediments obtained from a few hundreds of meters to 6,000 meters deep seabed.
This amount of virus would explain why there is nothing greater than micro-organisms in the seabed. The bacteria use organic matter as an energy source and multiply, but they are inevitably infected by the extraordinary number of bacteriophages, these bacteria are lysed and release immediately the organic matter back to the seabed, but no other body could use it .. . but other bacteria. Restarting the cycle again. Bacteriophages Therefore, interrupt the flow of matter and energy, this is called "viral diversion" (viral shunt in English).
This will solve the paradox that results from considering that the 10 cm of the seabed are the guardians of 30-45% of organic matter (as imvestigaciones above) and yet almost no animals that use these resources.
While this system deprives the animals of the vast deposits of nitroógeno, phosphorus and carbon, keeps a huge mass of bacteria, also makes an important contribution to bacterial metabolism and can cope with the severe restrictions of organic matter that the ecosystems suffer the deep sea.
It is certainly surprising that bacteriophages have this level of impact on the flow of matter and energy, says Jed Fuhrman parent of Marine Virology.
Surely this is not the last surprise of bacteriophages and viruses in general.
Translation and adaptation of an article from New Scientist:
http://www.newscientist.com/article/dn14616-how-viruses-shortcircuit-the-deep-sea-food-chain.html?DCMP = ILC-hmts & nsref = news5_head_dn14616
Biography of Felix d 'Herelle and interesting ideas and methods, perhaps soon we should use phage therapy as an alternative voice in the world for antibiotics: http:/
/ es.wikipedia.org / wiki / F% C3% A9lix_d% 27Herelle
article Original Nature:
http://www.nature.com/nature/journal/v454/n7208/abs/nature07268.html; jsessionid = A1F8E62D740321CE3B173B3360EB8677
orifinal job on the abundance of material on the seabed orana:
Proceedings of the National Academy of Sciences , vol 95, p 6578
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