{"id":30105,"date":"2016-11-08T00:35:33","date_gmt":"2016-11-08T00:35:33","guid":{"rendered":"https:\/\/new.igihe.com\/false-biosignatures-may-complicate-search-for\/"},"modified":"2016-11-08T00:36:34","modified_gmt":"2016-11-08T00:36:34","slug":"false-biosignatures-may-complicate-search-for","status":"publish","type":"post","link":"https:\/\/new.igihe.com\/english\/false-biosignatures-may-complicate-search-for\/","title":{"rendered":"&#8216;False&#8217; biosignatures may complicate search for ancient life on Earth, other planets"},"content":{"rendered":"<p>{Self-assembling carbon microstructures created in a lab by University of Colorado Boulder researchers could provide new clues &#8212; and new cautions &#8212; in efforts to identify microbial life preserved in the fossil record, both on Earth and elsewhere in the solar system.}<\/p>\n<p>The geological search for ancient life frequently zeroes in on fossilized organic structures or biominerals that can serve as &#8220;biosignatures,&#8221; that survive in the rock record over extremely long time scales. Mineral elements such as sulfur are often formed through biological activity. Microbes can also produce a variety of telltale extracellular structures that resemble sheaths and stalks.<\/p>\n<p>However, according to new findings published in the journal Nature Communications, carbon-sulfur microstructures that would be recognized today by some experts as biomaterials are capable of self-assembling under certain conditions, even without direct biological activity. These &#8220;false&#8221; biosignatures could potentially be misinterpreted as signs of biological activity due to their strong resemblance to microbial structures.<\/p>\n<p>&#8220;Surprisingly, we found that we could create all sorts of biogenic-like materials that have the right shape, structure and chemistry to match natural materials we assume are produced biologically,&#8221; said Associate Professor Alexis Templeton of CU Boulder&#8217;s Department of Geological Sciences and senior author of the new study.<\/p>\n<p>The study arose from field research in the Canadian High Arctic, where a team of scientists working with Templeton had identified sulfur-metabolizing organisms that live in shopping mall-sized mineral deposits that form on ice surfaces. Some of these sulfur deposits were returned to CU Boulder to determine whether they contained &#8220;biosignatures&#8221; that could be relevant to the search for life on Mars or Europa, one of Jupiter&#8217;s moons.<\/p>\n<p>Templeton and CU-Boulder Research Associate Julie Cosmidis then set out to study the underlying mechanisms of biological sulfur mineral formation before realizing that some of the &#8220;extracellular structures&#8221; and associated sulfur minerals could be reproduced in the lab without any organisms present.<\/p>\n<p>&#8220;It was very disconcerting- at first to see that the carbon-sulfur structures appear in our tests without biological activity, as they looked very microbial,&#8221; said Cosmidis, the lead study author.<\/p>\n<p>&#8220;But the fact that these structures self-assemble makes their discovery even more exciting. They challenge our conception of what a biosignature is, and they can teach us about unexpected interactions between carbon and sulfur,&#8221; said Cosmidis.<\/p>\n<p>The findings indicate that carbon-sulfur microstructures may no longer be surefire microbial indicators, but they are still useful for reconstructing environmental processes anywhere there is active sulfur cycling.<\/p>\n<p>&#8220;We&#8217;re interested to learn how organisms mediate mineralization and commonly it is challenging to demonstrate that a mineral was produced by living organism,&#8221; said Templeton. &#8220;This research is another step forward in understanding fundamental self-assembly processes that are important to materials scientists, biologists and chemists alike.&#8221;<\/p>\n<p>But while carbon-sulfur microstructures could confound efforts to identify ancient life, they may provide a roadmap to an entirely different innovation: Next-generation lithium-sulfur (Li-S) batteries.<\/p>\n<p>Rechargeable Li-S batteries are considered to be a promising successor to the lithium-ion batteries that power most of today&#8217;s consumer electronics. Li-S batteries can contain up to five times the energy of lithium-ion batteries, but present a number of manufacturing hurdles that have yet to be overcome on a commercial scale.<\/p>\n<p>The carbon-sulfur microstructures created in the new study, however, may solve one of the key challenges by encasing the sulfur in conductive carbon, potentially creating more electrically efficient Li-S batteries.<\/p>\n<p>&#8220;We&#8217;re making materials that have the desired properties and we&#8217;re doing it by mimicking a natural environmental process,&#8221; said Templeton. &#8220;It&#8217;s a promising new pathway to battery design.&#8221;<\/p>\n<figure class=\"spip-document spip-document-16244 aligncenter\"><img decoding=\"async\" src=\"https:\/\/en-images.igihe.com\/jpg\/160920094116_1_540x360.jpg\" alt=\"Associate Professor Alexis Templeton and Dr. Stephen Grasby prospecting for sulfur biominerals in a yellow sulfur deposit forming on a glacier surface in the High Arctic.\" \/><\/figure>\n","protected":false},"excerpt":{"rendered":"<p>{Self-assembling carbon microstructures created in a lab by University of Colorado Boulder researchers could provide new clues &#8212; and new cautions &#8212; in efforts to identify microbial life preserved in the fossil record, both on Earth and elsewhere in the solar system.} The geological search for ancient life frequently zeroes in on fossilized organic structures [&hellip;]<\/p>\n","protected":false},"author":3,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[9],"tags":[75],"byline":[2491],"hashtag":[],"class_list":["post-30105","post","type-post","status-publish","format-standard","hentry","category-science-technology","tag-homenews","byline-science-daily"],"bylines":[{"id":2491,"name":"SCIENCE DAILY","slug":"science-daily","description":"","image":{"id":0,"url":"https:\/\/secure.gravatar.com\/avatar\/?s=96&d=mm&f=y&r=g","alt":"Default avatar","title":"Default avatar","caption":"","mime_type":"image\/jpeg","sizes":[]},"user_id":null}],"contributors":[{"id":2491,"name":"SCIENCE DAILY","slug":"science-daily","description":"","image":{"id":0,"url":"https:\/\/secure.gravatar.com\/avatar\/?s=96&d=mm&f=y&r=g","alt":"Default avatar","title":"Default avatar","caption":"","mime_type":"image\/jpeg","sizes":[]},"user_id":null}],"featured_image":null,"_links":{"self":[{"href":"https:\/\/new.igihe.com\/english\/wp-json\/wp\/v2\/posts\/30105","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/new.igihe.com\/english\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/new.igihe.com\/english\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/new.igihe.com\/english\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/new.igihe.com\/english\/wp-json\/wp\/v2\/comments?post=30105"}],"version-history":[{"count":0,"href":"https:\/\/new.igihe.com\/english\/wp-json\/wp\/v2\/posts\/30105\/revisions"}],"wp:attachment":[{"href":"https:\/\/new.igihe.com\/english\/wp-json\/wp\/v2\/media?parent=30105"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/new.igihe.com\/english\/wp-json\/wp\/v2\/categories?post=30105"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/new.igihe.com\/english\/wp-json\/wp\/v2\/tags?post=30105"},{"taxonomy":"byline","embeddable":true,"href":"https:\/\/new.igihe.com\/english\/wp-json\/wp\/v2\/byline?post=30105"},{"taxonomy":"hashtag","embeddable":true,"href":"https:\/\/new.igihe.com\/english\/wp-json\/wp\/v2\/hashtag?post=30105"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}