Ignimbrite textural properties as determinants of endolithic colonization patterns from hyper-arid Atacama Desert Authors Beatriz Cámara National Museum of Natural Sciences-CSIC, Madrid. Shino Suzuki J. Craig Venter Institute, La Jolla, CA. Kenneth H Nealson 1. J. Craig Venter Institute, La Jolla, CA. 2. University of Southern California, Los Angeles, CA. Jacek Wierzchos National Museum of Natural Sciences-CSIC, Madrid. Carmen Ascaso National Museum of Natural Sciences-CSIC, Madrid. Octavio Artieda Department of Plant Biology, Ecology and Earth Sciences. University of Extremadura, Plasencia. Asunción de los Ríos National Museum of Natural Sciences-CSIC, Madrid, Spain. Keywords: Chroococcidiopsis sp., endoliths, ignimbrite, rock porosity, volcanic rock, Atacama Desert Abstract This study explores the photosynthetic microbial colonization of rhyolitic ignimbrites in Lomas de Tilocalar, a hyper-arid region of the Atacama Desert, Chile. Colonization appeared in the form of a green layer a few millimeters beneath the ignimbrite surface. Some ignimbrite rocks revealed two distinct micromorphological areas of identical mineralogical and chemical composition but different textural properties. According to texture, colonization patterns varied in terms of the extension and depth of colonization. The diversity of photosynthetic microorganisms was assessed by denaturing gradient gel electrophoresis (DGGE) of the 23S rRNA gene and by generating clone libraries of the 16S rRNA gene. We observed a low diversity of photosynthetic microorganisms colonizing the ignimbrite microhabitat. Most rRNA gene sequences recovered greatly resembled those of Chroococcidiopsis hypolith clones from arid deserts. These results point to highly restrictive conditions of the hyper-arid Atacama Desert conditioning the diversity of cyanobacteria, and suggest that microbial colonization and composition patterns might be determined by the microscale physico-chemical properties of the ignimbrite rocks. [Int Microbiol 2014; 17(4):235-247]Keywords: Chroococcidiopsis sp. · endoliths · ignimbrite · rock porosity · volcanic rock · Atacama Desert Author Biography Beatriz Cámara, National Museum of Natural Sciences-CSIC, Madrid. Downloads PDF Issue Vol. 17 No. 4 (2014) Section Research Articles License Submission of a manuscript to International Microbiology implies: that the work described has not been published before, including publication in the World Wide Web (except in the form of an Abstract or as part of a published lecture, review, or thesis); that it is not under consideration for publication elsewhere; that all the coauthors have agreed to its publication. The corresponding author signs for and accepts responsability for releasing this material and will act on behalf of any and all coauthors regarding the editorial review and publication process.If an article is accepted for publication in International Microbiology, the authors (or other copyright holder) must transfer to the journal the right–not exclusive–to reproduce and distribute the article including reprints, translations, photographic reproductions, microform, electronic form (offline, online) or any other reproductions of similar nature. Nevertheless, all article in International Microbiology will be available on the Internet to any reader at no cost. The journal allows users to freely download, copy, print, distribute, search, and link to the full text of any article, provided the authorship and source of the published article is cited. The copyright owner's consent does not include copying for new works, or resale. In these cases, the specific written permission of International Microbiology must first be obtained.Authors are requested to create a link to the published article on the journal's website. The link must be accompanied by the following text: "The original publication is available on LINK at <http://www.im.microbios.org>. Please use the appropiate URL for the article in LINK. Articles disseminated via LINK are indexed, abstracted, and referenced by many abstracting and information services, bibliographic networks, subscription agencies, library networks, and consortia.
