{"id":142221,"date":"2013-01-29T12:23:55","date_gmt":"2013-01-29T11:23:55","guid":{"rendered":"http:\/\/www.madrimasd.org\/blogs\/universo\/?p=142221"},"modified":"2013-01-29T12:23:55","modified_gmt":"2013-01-29T11:23:55","slug":"abundancia-y-diversidad-de-microrganismos-del-suelo-en-los-biomas-deserticos-desde-el-desierto-de-atacama-al-valle-de-la-muere","status":"publish","type":"post","link":"https:\/\/www.madrimasd.org\/blogs\/universo\/2013\/01\/29\/142221","title":{"rendered":"Abundancia y Diversidad de Microrganismos del Suelo en los Biomas Des\u00e9rticos (desde el desierto de Atacama al Valle de la Muere)"},"content":{"rendered":"

Solemos pensar que el vigor de la vida microbiana sigue los mismos patrones que la que observamos a simple vista, cuando no siempre es as\u00ed. Se trata de otro falso t\u00f3pico impregnante<\/span><\/a>. La vida lo invade todo. Incluso en los ambientes m\u00e1s \u00e1ridos de la Tierra, los microrganismos prosperan con facilidad<\/strong><\/span>. Como todos sabemos, en los desiertos<\/strong><\/span> el agua es un bien raro, m\u00e1s que escaso. Y entre todos los ecosistemas de tal naturaleza el desierto de Atacama<\/strong> <\/span>resulta ser el m\u00e1s inh\u00f3spito. Obviamente, cerca de la superficie el agua se evapora r\u00e1pidamente, el calor es sofocante y la radiaci\u00f3n solar muy intensa. Sin embargo, como ya os comentamos en otro post, la temperatura del suelo desciende r\u00e1pidamente conforme descendemos<\/span><\/a> a lo largo del perfil ed\u00e1fico. En consecuencia, a profundidades entre\u00a02 y 5 metros<\/span><\/strong> el agua se evapora y\/o asciende por capilaridad lentamente y m\u00e1s aun si la secuencia de horizontes ed\u00e1ficos rompe el trasporte de este l\u00edquido por la mentada capilaridad de abajo a arriba. M\u00e1s aun, los dep\u00f3sitos salinos que abundan en este tipo de biomas atesoran la propiedad de absorber el vapor de agua de la atm\u00f3sfera y concentrarla en forma de pel\u00edculas alrededor de los cristales de sal<\/strong><\/span>. Y como bacterias, arqueas y<\/strong><\/span> otros peque\u00f1os bichitos viven en estos microambiente acu\u00e1ticos, prosperan\u00a0all\u00ed<\/strong><\/span>. Si el agua escasea adquiere formas quiescentes durante much\u00edsimos a\u00f1os, a la espera de \u00e9pocas m\u00e1s favorables. Por lo tanto, a las profundidades mentadas, ni los rayos ultravioletas da\u00f1an la vida, ni las temperaturas son sofocantes<\/strong><\/span>. Ahora\u00a0bien el ox\u00edgeno escasea, aunque tal hecho no es un impedimento para que medren muchos microrganismos. Los medios salinos tambi\u00e9n tienen la propiedad de<\/strong> <\/span>afectar al punto de congelaci\u00f3n del agua<\/strong><\/span>, de tal modo que esta puede permanecer en forma l\u00edquida muchos grados bajo cero, evitando paros biol\u00f3gicos. Pues bien, todas estas propiedades parecen ser t\u00edpicas de los regolitos marcianos<\/strong><\/span>. Por tanto, no debe extra\u00f1ar que los expertos en la b\u00fasqueda de vida escarben varios metros bajo la superficie del suelo en busca de rastros de vida<\/strong><\/span>. Lo que resulta sumamente curioso es que los cient\u00edficos que intentar analizar la biodiversidad de los suelos terrestres se conformen con muestrear unos pocos metros superficiales, soslayando la biomasa y diversidad del mundo microbiano m\u00e1s tel\u00farico (profundo)<\/span>.<\/strong> Tal hecho deviene en un obst\u00e1culo con vistas a entender la estructura y din\u00e1mica de la vida en el suelo. Por tanto se antoja parad\u00f3jico que, con vistas a progresar en nuestro conocimiento de la biolog\u00eda del suelo, debamos esperar a que las investigaciones destinadas a mejorar la b\u00fasqueda de vida en Marte avancen<\/strong><\/span>. Desde otro punto de vista, surgen varias posibles diferencias de los patrones de vida microbiana entre los suelos de ambientes tan hostiles respecto a los que no lo son<\/strong> <\/span>(\u2026)<\/p>\n

\"atacama-desert-microorganisms\"<\/p>\n

Abundancia de los Microrganismos en los Desiertos. Fuente: Universe Today (Microbes have been found flourishing beneath the surface of the Atacama Desert. (Parro et al.\/CAB\/SINC)<\/span><\/a>
\n<\/span>1. (\u2026)\u00a0El patr\u00f3n de distribuci\u00f3n de la biomasa (y de la propia materia org\u00e1nica) a lo largo de un perfil de suelos des\u00e9rticos puede encontrase invertido respecto a otro normal, de tal modo que aumenta en profundidad (hasta cierto punto) en los segundos, al contrario que en los primeros. <\/span><\/p>\n

2. Que como ocurre en la vida emergida de estos ecosistemas, los microrganismos se agrupen en <\/span>islas de fertilidad<\/span><\/a>, separados por mares de aridez, es decir que <\/span>se concentren en parches en medio de una matriz sin, o muy pobre, en organismos<\/span><\/a>.<\/span><\/p>\n

3. Me han narrado en m\u00e1s de una ocasi\u00f3n observaciones desconcertantes en suelos des\u00e9rticos, consistentes en que, bajo unos cent\u00edmetros de yermo suelo, aparece una capa oscura mucho m\u00e1s rica en materia org\u00e1nica que la\u00a0superficial, sin que existan rasgos que delaten que se trata de\u00a0horizontes superficiales enterrados. EStamos ante\u00a0una conjetura digna de ser prospeccionada ya que\u00a0podr\u00eda subestimarse el almacenamiento de carbono org\u00e1nico en suelos \u00e1ridos.<\/span><\/p>\n

Juan Jos\u00e9 Ib\u00e1\u00f1ez<\/span><\/strong><\/p>\n

Ecological patterns of micro-organisms in desert soils<\/span>.<\/strong><\/p>\n

Opfell JB<\/span><\/a>, Zebal GP<\/span><\/a>.<\/p>\n

Source<\/span>: <\/strong>Philco-Ford Corporation, Aeronutronic Division, Newport Beach, California, USA.<\/p>\n

Abstract<\/strong><\/span><\/p>\n

The Atacama Desert’s hardy aerobic microbial populations have been found to occupy ecological niches substantially different from those occupied by aerobic micro-organisms in the California and Valley<\/strong> of 10 000 Smokes deserts. Two specialized groups of microflora, the actinomycetes and micro-aerophiles, appear to be abundant in some portions of the Atacama Desert<\/strong>, though many of the bacterial and mold types and species common in the California deserts are absent<\/strong>. The factors defining the ecological niches and relationships of microbial populations in these soils are largely unknown<\/strong>. In several respects, moreover, micro-environments in these soils are similar to some of those expected on Mars<\/strong>. For the purpose of establishing the engineering constraints on the design of life detection instruments and their sampling and processing components, the nature and diversity of species of micro-organisms prevalent in the soils of extremely dry climates of the earth have not been adequately investigated<\/strong>. Useful ecological information about these soils will include an estimate of the likely lower limit in numbers or mass of viable aggregates in the autochthonous populations and the survivability of these populations<\/strong> under mechanical processing and isolated storage. Knowledge of the artificial niches, growth media for example, which members of these populations accept, will be useful in designing life detection instruments themselves. The range of practical designs for soil sampling devices will be determined by the nature of the particles and surfaces, and their depths, on which various physiological groups or largest populations of micro-organisms reside in the extremely dry deserts of the earth<\/strong>. The results of several exploratory experiments are used to provide some understanding of the environment and the ecological patterns of micro-organisms in soils of the earth’s driest deserts.<\/p>\n

PMID: 11973846<\/p>\n

[PubMed – indexed for MEDLINE]<\/p>\n

MeSH Terms, Substances<\/span><\/strong><\/a> <\/strong><\/p>\n

Universe Today<\/span><\/a><\/h2>\n

Researchers from the Center of Astrobiology (CAB<\/span><\/a>) in Spain and the Catholic University of the North in Chile<\/strong> have found an \u201coasis\u201d of microorganisms living two meters beneath the arid soil of the Atacama<\/strong>, proving that even on the driest place on Earth, life finds a way.<\/p>\n

Chile\u2019s Atacama Desert receives on average less than .01 cm (.004 inches) of rain per year. In some locations rain has not fallen for over 400 years. But even in this harsh environment there is moisture\u2026 just enough, at least, for rock salts and other compounds that can absorb any traces of water to support microbial life beneath the surface.<\/strong><\/p>\n

Using a device called SOLID<\/span><\/a>(Signs Of LIfe Detection) developed by CAB, the researchers were able to identify the presence of microorganisms living on thin films of water within the salty subsurface soil<\/strong>.<\/p>\n

Even the substrate itself is able to absorb moisture from the air, concentrating it into films only a few microns thick around the salt crystals<\/strong>. This gives the microorganisms everything they need to survive and flourish \u2014 two to three meters underground<\/strong>.<\/p>\n

Read more: http:\/\/www.universetoday.com\/93621\/solid-clues-for-finding-life-on-mars\/#ixzz1xOxtTuco<\/a><\/p>\n

At that depth, there is no sunlight and no oxygen, but there is life.<\/span><\/p>\n

And even when researchers dug to a depth of five meters<\/strong> (a little over 16 feet) and took samples back to a lab, they were able to not only locate microorganisms but also revive them with the addition of a little water<\/strong>.<\/span><\/p>\n

Of course, the implications for finding life \u2014or at least the remains of its past existence \u2014 on Mars is evident. Mars has been shown to have saline deposits in many regions, and the salt is what helps water remain liquid, longer<\/strong>.<\/span><\/p>\n

\u201cThe high concentration of salt has a double effect: it absorbs water between the crystals and lowers the freezing point, so that they can have thin films of water (in brine) at temperatures several degrees below zero, up to minus 20 C<\/strong>,\u201dsaid Victor Parro, researcher from the Center of Astrobiology (INTA-CSIC, Spain<\/strong>) and coordinator of the study. This is within the temperature range of many regions of Mars, and also anything located several meters below the surface would be well protected from UV radiation from the Sun<\/strong>.<\/span><\/p>\n

\u201cIf there are similar microbes on Mars or remains in similar conditions to the ones we have found in Atacama<\/strong>, we could detect them with instruments like SOLID,\u201d Parro said.<\/span><\/p>\n

The development of a new version of the SOLID instrument is currently underway for ESA\u2019s ExoMars program<\/strong>.<\/span><\/p>\n

Read more here on the Science Codex article<\/span><\/p>\n

Read more: http:\/\/www.universetoday.com\/93621\/solid-clues-for-finding-life-on-mars\/#ixzz1xP1GvaC3<\/span><\/p>\n","protected":false},"excerpt":{"rendered":"

Solemos pensar que el vigor de la vida microbiana sigue los mismos patrones que la que observamos a simple vista, cuando no siempre es as\u00ed. Se trata de otro falso t\u00f3pico impregnante. La vida lo invade todo. Incluso en los ambientes m\u00e1s \u00e1ridos de la Tierra, los microrganismos prosperan con facilidad. Como todos sabemos, en los desiertos el agua es un bien raro, m\u00e1s que escaso. Y entre todos los ecosistemas de tal naturaleza el desierto de Atacama resulta ser el m\u00e1s inh\u00f3spito. Obviamente, cerca de la superficie el agua se evapora r\u00e1pidamente, el calor es sofocante y la radiaci\u00f3n\u2026<\/p>\n","protected":false},"author":26,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"ngg_post_thumbnail":0},"categories":[596,608,603,598],"tags":[47284,17976,46734],"blocksy_meta":{"styles_descriptor":{"styles":{"desktop":"","tablet":"","mobile":""},"google_fonts":[],"version":4}},"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/posts\/142221"}],"collection":[{"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/users\/26"}],"replies":[{"embeddable":true,"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/comments?post=142221"}],"version-history":[{"count":7,"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/posts\/142221\/revisions"}],"predecessor-version":[{"id":143731,"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/posts\/142221\/revisions\/143731"}],"wp:attachment":[{"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/media?parent=142221"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/categories?post=142221"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/tags?post=142221"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}