{"id":227,"date":"2018-01-18T18:30:56","date_gmt":"2018-01-18T18:30:56","guid":{"rendered":"https:\/\/courses.lumenlearning.com\/wm-nmbiology2\/chapter\/life-in-moderate-and-extreme-environments\/"},"modified":"2024-04-26T18:04:15","modified_gmt":"2024-04-26T18:04:15","slug":"life-in-moderate-and-extreme-environments","status":"publish","type":"chapter","link":"https:\/\/courses.lumenlearning.com\/wm-nmbiology2\/chapter\/life-in-moderate-and-extreme-environments\/","title":{"raw":"Life in Moderate and Extreme Environments","rendered":"Life in Moderate and Extreme Environments"},"content":{"raw":"<div class=\"textbox learning-objectives\">\r\n<h3>Learning Outcomes<\/h3>\r\n<ul>\r\n \t<li>Discuss the distinguishing features of extremophiles<\/li>\r\n<\/ul>\r\n<\/div>\r\nSome organisms have developed strategies that allow them to survive harsh conditions. Prokaryotes thrive in a vast array of environments: some grow in conditions that would seem very normal to us, whereas others are able to thrive and grow under conditions that would kill a plant or animal. Almost all prokaryotes have a cell wall, a protective structure that allows them to survive in both hyper- and hypo-osmotic conditions. Some soil bacteria are able to form endospores that resist heat and drought, thereby allowing the organism to survive until favorable conditions recur. These adaptations, along with others, allow bacteria to be the most abundant life form in all terrestrial and aquatic ecosystems.\r\n\r\nOther bacteria and archaea are adapted to grow under extreme conditions and are called <b>extremophiles<\/b>, meaning \u201clovers of extremes.\u201d Extremophiles have been found in all kinds of environments: the depth of the oceans, hot springs, the Arctic and the Antarctic, in very dry places, deep inside Earth, in harsh chemical environments, and in high radiation environments, just to mention a few.\r\n\r\n[caption id=\"attachment_1244\" align=\"alignright\" width=\"300\"]<img class=\"wp-image-1244\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/2840\/2018\/01\/18183052\/Figure_22_01_04.jpg\" alt=\"This micrograph shows an oval Deinococcus about 2.5 microns in diameter cell dividing.\" width=\"300\" height=\"345\" \/> Figure\u00a01. <em>Deinococcus radiodurans<\/em>, visualized in a\u00a0false color transmission electron micrograph (credit: modification of work by Michael Daly; scale-bar data from Matt Russell)[\/caption]\r\n\r\nOther extremophiles, like <b>radioresistant<\/b> organisms, do not prefer an extreme environment (in this case, one with high levels of radiation), but have adapted to survive in it. For example,\u00a0<em>Deinococcus radiodurans<\/em>, shown in Figure 1, is a prokaryote that can tolerate very high doses of ionizing radiation. It has developed DNA repair mechanisms that allow it to reconstruct its chromosome even if it has been broken into hundreds of pieces by radiation or heat.\r\n\r\nThese organisms give us a better understanding of prokaryotic diversity and open up the possibility of finding new prokaryotic species that may lead to the discovery of new therapeutic drugs or have industrial applications. Because they have specialized adaptations that allow them to live in extreme conditions, many extremophiles cannot survive in moderate environments.\r\n\r\nThere are many different groups of extremophiles: they are identified based on the conditions in which they grow best, and several habitats are extreme in multiple ways. For example, a soda lake is both salty and alkaline, so organisms that live in a soda lake must be both alkaliphiles and halophiles (Table\u00a01).\r\n<table id=\"tab-ch22-01-01\" summary=\"\">\r\n<thead>\r\n<tr>\r\n<th colspan=\"2\">Table\u00a01. Extremophiles and Their Preferred Conditions<\/th>\r\n<\/tr>\r\n<tr>\r\n<th>Extremophile Type<\/th>\r\n<th>Conditions for Optimal Growth<\/th>\r\n<\/tr>\r\n<\/thead>\r\n<tbody>\r\n<tr>\r\n<td>Acidophiles<\/td>\r\n<td>pH 3 or below<\/td>\r\n<\/tr>\r\n<tr>\r\n<td>Alkaliphiles<\/td>\r\n<td>pH 9 or above<\/td>\r\n<\/tr>\r\n<tr>\r\n<td>Thermophiles<\/td>\r\n<td>Temperature 60\u201380 \u00b0C (140\u2013176 \u00b0F)<\/td>\r\n<\/tr>\r\n<tr>\r\n<td>Hyperthermophiles<\/td>\r\n<td>Temperature 80\u2013122 \u00b0C (176\u2013250 \u00b0F)<\/td>\r\n<\/tr>\r\n<tr>\r\n<td>Psychrophiles<\/td>\r\n<td>Temperature of \u221215\u201310 \u00b0C (5\u201350 \u00b0F) or lower<\/td>\r\n<\/tr>\r\n<tr>\r\n<td>Halophiles<\/td>\r\n<td>Salt concentration of at least 0.2 M<\/td>\r\n<\/tr>\r\n<tr>\r\n<td>Osmophiles<\/td>\r\n<td>High sugar concentration<\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n<div class=\"textbox key-takeaways\">\r\n<h3>Prokaryotes in the Dead Sea<\/h3>\r\nOne example of a very harsh environment is the Dead Sea, a hypersaline basin that is located between Jordan and Israel. Hypersaline environments are essentially concentrated seawater. In the Dead Sea, the sodium concentration is 10 times higher than that of seawater, and the water contains high levels of magnesium (about 40 times higher than in seawater) that would be toxic to most living things. Iron, calcium, and magnesium, elements that form divalent ions (Fe<sup>2+<\/sup>, Ca<sup>2+<\/sup>, and Mg<sup>2+<\/sup>), produce what is commonly referred to as \u201chard\u201d water.\r\n\r\nTaken together, the high concentration of divalent cations, the acidic pH (6.0), and the intense solar radiation flux make the Dead Sea a unique, and uniquely hostile, ecosystem[footnote]Bodaker, I, Itai, S, Suzuki, MT, Feingersch, R, Rosenberg, M, Maguire, ME, Shimshon, B, and others. Comparative community genomics in the Dead Sea: An increasingly extreme environment. <em>The ISME Journal<\/em> 4 (2010): 399\u2013407, doi:10.1038\/ismej.2009.141. published online 24 December 2009.[\/footnote] (Figure\u00a02).\r\n\r\n[caption id=\"attachment_1245\" align=\"aligncenter\" width=\"1024\"]<img class=\"size-large wp-image-1245\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/2840\/2018\/01\/18183054\/Figure_22_01_05-1024x419.jpg\" alt=\"Photo A shows the Dead Sea and its accompanying brown shoreline. Micrograph B shows rod-shaped halobacteria.\" width=\"1024\" height=\"419\" \/> Figure\u00a02. (a) The Dead Sea is hypersaline. Nevertheless, salt-tolerant bacteria thrive in this sea. (b) These halobacteria cells can form salt-tolerant bacterial mats. (credit a: Julien Menichini; credit b: NASA; scale-bar data from Matt Russell)[\/caption]\r\n\r\nWhat sort of prokaryotes do we find in the Dead Sea? The extremely salt-tolerant bacterial mats include <em>Halobacterium<\/em>, <em>Haloferax volcanii <\/em>(which is found in other locations, not only the Dead Sea), <em>Halorubrum sodomense<\/em>, and <em>Halobaculum gomorrense<\/em>, and the archaea <em>Haloarcula marismortui<\/em>, among others.\r\n\r\n<\/div>\r\n<div class=\"textbox tryit\">\r\n<h3>Try It<\/h3>\r\nhttps:\/\/assess.lumenlearning.com\/practice\/885e0ad5-1a54-4963-aa16-3b9a852d7763\r\n<\/div>","rendered":"<div class=\"textbox learning-objectives\">\n<h3>Learning Outcomes<\/h3>\n<ul>\n<li>Discuss the distinguishing features of extremophiles<\/li>\n<\/ul>\n<\/div>\n<p>Some organisms have developed strategies that allow them to survive harsh conditions. Prokaryotes thrive in a vast array of environments: some grow in conditions that would seem very normal to us, whereas others are able to thrive and grow under conditions that would kill a plant or animal. Almost all prokaryotes have a cell wall, a protective structure that allows them to survive in both hyper- and hypo-osmotic conditions. Some soil bacteria are able to form endospores that resist heat and drought, thereby allowing the organism to survive until favorable conditions recur. These adaptations, along with others, allow bacteria to be the most abundant life form in all terrestrial and aquatic ecosystems.<\/p>\n<p>Other bacteria and archaea are adapted to grow under extreme conditions and are called <b>extremophiles<\/b>, meaning \u201clovers of extremes.\u201d Extremophiles have been found in all kinds of environments: the depth of the oceans, hot springs, the Arctic and the Antarctic, in very dry places, deep inside Earth, in harsh chemical environments, and in high radiation environments, just to mention a few.<\/p>\n<div id=\"attachment_1244\" style=\"width: 310px\" class=\"wp-caption alignright\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-1244\" class=\"wp-image-1244\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/2840\/2018\/01\/18183052\/Figure_22_01_04.jpg\" alt=\"This micrograph shows an oval Deinococcus about 2.5 microns in diameter cell dividing.\" width=\"300\" height=\"345\" \/><\/p>\n<p id=\"caption-attachment-1244\" class=\"wp-caption-text\">Figure\u00a01. <em>Deinococcus radiodurans<\/em>, visualized in a\u00a0false color transmission electron micrograph (credit: modification of work by Michael Daly; scale-bar data from Matt Russell)<\/p>\n<\/div>\n<p>Other extremophiles, like <b>radioresistant<\/b> organisms, do not prefer an extreme environment (in this case, one with high levels of radiation), but have adapted to survive in it. For example,\u00a0<em>Deinococcus radiodurans<\/em>, shown in Figure 1, is a prokaryote that can tolerate very high doses of ionizing radiation. It has developed DNA repair mechanisms that allow it to reconstruct its chromosome even if it has been broken into hundreds of pieces by radiation or heat.<\/p>\n<p>These organisms give us a better understanding of prokaryotic diversity and open up the possibility of finding new prokaryotic species that may lead to the discovery of new therapeutic drugs or have industrial applications. Because they have specialized adaptations that allow them to live in extreme conditions, many extremophiles cannot survive in moderate environments.<\/p>\n<p>There are many different groups of extremophiles: they are identified based on the conditions in which they grow best, and several habitats are extreme in multiple ways. For example, a soda lake is both salty and alkaline, so organisms that live in a soda lake must be both alkaliphiles and halophiles (Table\u00a01).<\/p>\n<table id=\"tab-ch22-01-01\" summary=\"\">\n<thead>\n<tr>\n<th colspan=\"2\">Table\u00a01. Extremophiles and Their Preferred Conditions<\/th>\n<\/tr>\n<tr>\n<th>Extremophile Type<\/th>\n<th>Conditions for Optimal Growth<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Acidophiles<\/td>\n<td>pH 3 or below<\/td>\n<\/tr>\n<tr>\n<td>Alkaliphiles<\/td>\n<td>pH 9 or above<\/td>\n<\/tr>\n<tr>\n<td>Thermophiles<\/td>\n<td>Temperature 60\u201380 \u00b0C (140\u2013176 \u00b0F)<\/td>\n<\/tr>\n<tr>\n<td>Hyperthermophiles<\/td>\n<td>Temperature 80\u2013122 \u00b0C (176\u2013250 \u00b0F)<\/td>\n<\/tr>\n<tr>\n<td>Psychrophiles<\/td>\n<td>Temperature of \u221215\u201310 \u00b0C (5\u201350 \u00b0F) or lower<\/td>\n<\/tr>\n<tr>\n<td>Halophiles<\/td>\n<td>Salt concentration of at least 0.2 M<\/td>\n<\/tr>\n<tr>\n<td>Osmophiles<\/td>\n<td>High sugar concentration<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<div class=\"textbox key-takeaways\">\n<h3>Prokaryotes in the Dead Sea<\/h3>\n<p>One example of a very harsh environment is the Dead Sea, a hypersaline basin that is located between Jordan and Israel. Hypersaline environments are essentially concentrated seawater. In the Dead Sea, the sodium concentration is 10 times higher than that of seawater, and the water contains high levels of magnesium (about 40 times higher than in seawater) that would be toxic to most living things. Iron, calcium, and magnesium, elements that form divalent ions (Fe<sup>2+<\/sup>, Ca<sup>2+<\/sup>, and Mg<sup>2+<\/sup>), produce what is commonly referred to as \u201chard\u201d water.<\/p>\n<p>Taken together, the high concentration of divalent cations, the acidic pH (6.0), and the intense solar radiation flux make the Dead Sea a unique, and uniquely hostile, ecosystem<a class=\"footnote\" title=\"Bodaker, I, Itai, S, Suzuki, MT, Feingersch, R, Rosenberg, M, Maguire, ME, Shimshon, B, and others. Comparative community genomics in the Dead Sea: An increasingly extreme environment. The ISME Journal 4 (2010): 399\u2013407, doi:10.1038\/ismej.2009.141. published online 24 December 2009.\" id=\"return-footnote-227-1\" href=\"#footnote-227-1\" aria-label=\"Footnote 1\"><sup class=\"footnote\">[1]<\/sup><\/a> (Figure\u00a02).<\/p>\n<div id=\"attachment_1245\" style=\"width: 1034px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-1245\" class=\"size-large wp-image-1245\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/2840\/2018\/01\/18183054\/Figure_22_01_05-1024x419.jpg\" alt=\"Photo A shows the Dead Sea and its accompanying brown shoreline. Micrograph B shows rod-shaped halobacteria.\" width=\"1024\" height=\"419\" \/><\/p>\n<p id=\"caption-attachment-1245\" class=\"wp-caption-text\">Figure\u00a02. (a) The Dead Sea is hypersaline. Nevertheless, salt-tolerant bacteria thrive in this sea. (b) These halobacteria cells can form salt-tolerant bacterial mats. (credit a: Julien Menichini; credit b: NASA; scale-bar data from Matt Russell)<\/p>\n<\/div>\n<p>What sort of prokaryotes do we find in the Dead Sea? The extremely salt-tolerant bacterial mats include <em>Halobacterium<\/em>, <em>Haloferax volcanii <\/em>(which is found in other locations, not only the Dead Sea), <em>Halorubrum sodomense<\/em>, and <em>Halobaculum gomorrense<\/em>, and the archaea <em>Haloarcula marismortui<\/em>, among others.<\/p>\n<\/div>\n<div class=\"textbox tryit\">\n<h3>Try It<\/h3>\n<p>\t<iframe id=\"assessment_practice_885e0ad5-1a54-4963-aa16-3b9a852d7763\" class=\"resizable\" src=\"https:\/\/assess.lumenlearning.com\/practice\/885e0ad5-1a54-4963-aa16-3b9a852d7763?iframe_resize_id=assessment_practice_id_885e0ad5-1a54-4963-aa16-3b9a852d7763\" frameborder=\"0\" style=\"border:none;width:100%;height:100%;min-height:300px;\"><br \/>\n\t<\/iframe>\n<\/div>\n\n\t\t\t <section class=\"citations-section\" role=\"contentinfo\">\n\t\t\t <h3>Candela Citations<\/h3>\n\t\t\t\t\t <div>\n\t\t\t\t\t\t <div id=\"citation-list-227\">\n\t\t\t\t\t\t\t <div class=\"licensing\"><div class=\"license-attribution-dropdown-subheading\">CC licensed content, Shared previously<\/div><ul class=\"citation-list\"><li>Biology. <strong>Provided by<\/strong>: OpenStax CNX. <strong>Located at<\/strong>: <a target=\"_blank\" href=\"http:\/\/cnx.org\/contents\/185cbf87-c72e-48f5-b51e-f14f21b5eabd@10.8\">http:\/\/cnx.org\/contents\/185cbf87-c72e-48f5-b51e-f14f21b5eabd@10.8<\/a>. <strong>License<\/strong>: <em><a target=\"_blank\" rel=\"license\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY: Attribution<\/a><\/em>. <strong>License Terms<\/strong>: Download for free at http:\/\/cnx.org\/contents\/185cbf87-c72e-48f5-b51e-f14f21b5eabd@10.8<\/li><\/ul><\/div>\n\t\t\t\t\t\t <\/div>\n\t\t\t\t\t <\/div>\n\t\t\t <\/section><hr class=\"before-footnotes clear\" \/><div class=\"footnotes\"><ol><li id=\"footnote-227-1\">Bodaker, I, Itai, S, Suzuki, MT, Feingersch, R, Rosenberg, M, Maguire, ME, Shimshon, B, and others. Comparative community genomics in the Dead Sea: An increasingly extreme environment. <em>The ISME Journal<\/em> 4 (2010): 399\u2013407, doi:10.1038\/ismej.2009.141. published online 24 December 2009. <a href=\"#return-footnote-227-1\" class=\"return-footnote\" aria-label=\"Return to footnote 1\">&crarr;<\/a><\/li><\/ol><\/div>","protected":false},"author":17,"menu_order":4,"template":"","meta":{"_candela_citation":"[{\"type\":\"cc\",\"description\":\"Biology\",\"author\":\"\",\"organization\":\"OpenStax CNX\",\"url\":\"http:\/\/cnx.org\/contents\/185cbf87-c72e-48f5-b51e-f14f21b5eabd@10.8\",\"project\":\"\",\"license\":\"cc-by\",\"license_terms\":\"Download for free at http:\/\/cnx.org\/contents\/185cbf87-c72e-48f5-b51e-f14f21b5eabd@10.8\"}]","CANDELA_OUTCOMES_GUID":"8a827df3-3620-4c40-8e2c-45ff722a5910, ad990f26-4b24-46f1-a5ff-82c3dd7a9480","pb_show_title":"on","pb_short_title":"","pb_subtitle":"","pb_authors":[],"pb_section_license":""},"chapter-type":[],"contributor":[],"license":[],"class_list":["post-227","chapter","type-chapter","status-publish","hentry"],"part":216,"_links":{"self":[{"href":"https:\/\/courses.lumenlearning.com\/wm-nmbiology2\/wp-json\/pressbooks\/v2\/chapters\/227","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/courses.lumenlearning.com\/wm-nmbiology2\/wp-json\/pressbooks\/v2\/chapters"}],"about":[{"href":"https:\/\/courses.lumenlearning.com\/wm-nmbiology2\/wp-json\/wp\/v2\/types\/chapter"}],"author":[{"embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/wm-nmbiology2\/wp-json\/wp\/v2\/users\/17"}],"version-history":[{"count":7,"href":"https:\/\/courses.lumenlearning.com\/wm-nmbiology2\/wp-json\/pressbooks\/v2\/chapters\/227\/revisions"}],"predecessor-version":[{"id":2943,"href":"https:\/\/courses.lumenlearning.com\/wm-nmbiology2\/wp-json\/pressbooks\/v2\/chapters\/227\/revisions\/2943"}],"part":[{"href":"https:\/\/courses.lumenlearning.com\/wm-nmbiology2\/wp-json\/pressbooks\/v2\/parts\/216"}],"metadata":[{"href":"https:\/\/courses.lumenlearning.com\/wm-nmbiology2\/wp-json\/pressbooks\/v2\/chapters\/227\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/courses.lumenlearning.com\/wm-nmbiology2\/wp-json\/wp\/v2\/media?parent=227"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/wm-nmbiology2\/wp-json\/pressbooks\/v2\/chapter-type?post=227"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/wm-nmbiology2\/wp-json\/wp\/v2\/contributor?post=227"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/wm-nmbiology2\/wp-json\/wp\/v2\/license?post=227"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}