<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Lumian, Jessica E.</style></author><author><style face="normal" font="default" size="100%">Jungblut, Anne D.</style></author><author><style face="normal" font="default" size="100%">Dillon, Megan L.</style></author><author><style face="normal" font="default" size="100%">Hawes, Ian</style></author><author><style face="normal" font="default" size="100%">Peter T. Doran</style></author><author><style face="normal" font="default" size="100%">Mackey, Tyler J.</style></author><author><style face="normal" font="default" size="100%">Dick, Gregory J.</style></author><author><style face="normal" font="default" size="100%">Grettenberger, Christen L.</style></author><author><style face="normal" font="default" size="100%">Sumner, Dawn Y.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Metabolic capacity of the Antarctic cyanobacterium &lt;I&gt;Phormidium pseudopriestleyi&lt;/I&gt; that sustains oxygenic photosynthesis in the presence of hydrogen sulfide</style></title><secondary-title><style face="normal" font="default" size="100%">Genes</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2021</style></year><pub-dates><date><style  face="normal" font="default" size="100%">03/2021</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">https://www.mdpi.com/2073-4425/12/3/426</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">12</style></volume><pages><style face="normal" font="default" size="100%">426</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Sulfide inhibits oxygenic photosynthesis by blocking electron transfer between H&lt;sub&gt;2&lt;/sub&gt;O and the oxygen-evolving complex in the D1 protein of Photosystem II. The ability of cyanobacteria to counter this effect has implications for understanding the productivity of benthic microbial mats in sulfidic environments throughout Earth history. In Lake Fryxell, Antarctica, the benthic, filamentous cyanobacterium &lt;em&gt;Phormidium pseudopriestleyi&lt;/em&gt; creates a 1&amp;ndash;2 mm thick layer of 50 &amp;micro;mol L&lt;sup&gt;&amp;minus;1&lt;/sup&gt; O&lt;sub&gt;2&lt;/sub&gt; in otherwise sulfidic water, demonstrating that it sustains oxygenic photosynthesis in the presence of sulfide. A metagenome-assembled genome of &lt;em&gt;P. pseudopriestleyi&lt;/em&gt; indicates a genetic capacity for oxygenic photosynthesis, including multiple copies of &lt;em&gt;psbA&lt;/em&gt; (encoding the D1 protein of Photosystem II), and anoxygenic photosynthesis with a copy of &lt;em&gt;sqr&lt;/em&gt; (encoding the sulfide quinone reductase protein that oxidizes sulfide). The genomic content of &lt;em&gt;P. pseudopriestleyi&lt;/em&gt; is consistent with sulfide tolerance mechanisms including increasing &lt;em&gt;psbA&lt;/em&gt; expression or directly oxidizing sulfide with sulfide quinone reductase. However, the ability of the organism to reduce Photosystem I via sulfide quinone reductase while Photosystem II is sulfide-inhibited, thereby performing anoxygenic photosynthesis in the presence of sulfide, has yet to be demonstrated.&amp;nbsp;&lt;/p&gt;</style></abstract><issue><style face="normal" font="default" size="100%">3</style></issue></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Dillon, Megan L.</style></author><author><style face="normal" font="default" size="100%">Ian Hawes</style></author><author><style face="normal" font="default" size="100%">Jungblut, Anne D.</style></author><author><style face="normal" font="default" size="100%">Mackey, Tyler J.</style></author><author><style face="normal" font="default" size="100%">Eisen, Jonathan A.</style></author><author><style face="normal" font="default" size="100%">Peter T. Doran</style></author><author><style face="normal" font="default" size="100%">Sumner, Dawn Y.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Energetic and environmental constraints on the community structure of benthic microbial mats in Lake Fryxell, Antarctica</style></title><secondary-title><style face="normal" font="default" size="100%">FEMS Microbiology Ecology</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Antarctica</style></keyword><keyword><style  face="normal" font="default" size="100%">energy</style></keyword><keyword><style  face="normal" font="default" size="100%">Lake Fryxell</style></keyword><keyword><style  face="normal" font="default" size="100%">microbial mat</style></keyword><keyword><style  face="normal" font="default" size="100%">Oxygen</style></keyword><keyword><style  face="normal" font="default" size="100%">Photosynthetically Active Radiation</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2020</style></year><pub-dates><date><style  face="normal" font="default" size="100%">02/2020</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">https://academic.oup.com/femsec/article/96/2/fiz207/5697196</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">96</style></volume><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Ecological communities are regulated by the flow of energy through environments. Energy flow is typically limited by access to photosynthetically active radiation (PAR) and oxygen concentration (O&lt;sub&gt;2&lt;/sub&gt;). The microbial mats growing on the bottom of Lake Fryxell, Antarctica, have well-defined environmental gradients in PAR and (O&lt;sub&gt;2&lt;/sub&gt;). We analyzed the metagenomes of layers from these microbial mats to test the extent to which access to oxygen and light controls community structure. We found variation in the diversity and relative abundances of Archaea, Bacteria and Eukaryotes across three (O&lt;sub&gt;2&lt;/sub&gt;) and PAR conditions: high (O&lt;sub&gt;2&lt;/sub&gt;) and maximum PAR, variable (O&lt;sub&gt;2&lt;/sub&gt;) with lower maximum PAR, and low (O&lt;sub&gt;2&lt;/sub&gt;) and maximum PAR. We found distinct communities structured by the optimization of energy use on a millimeter-scale across these conditions. In mat layers where (O&lt;sub&gt;2&lt;/sub&gt;) was saturated, PAR structured the community. In contrast, (O&lt;sub&gt;2&lt;/sub&gt;) positively correlated with diversity and affected the distribution of dominant populations across the three habitats, suggesting that meter-scale diversity is structured by energy availability. Microbial communities changed across covarying gradients of PAR and (O&lt;sub&gt;2&lt;/sub&gt;). The comprehensive metagenomic analysis suggests that the benthic microbial communities in Lake Fryxell are structured by energy flow across both meter- and millimeter-scales.&lt;/p&gt;</style></abstract><issue><style face="normal" font="default" size="100%">2</style></issue></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Dillon, Megan L.</style></author><author><style face="normal" font="default" size="100%">Hawes, Ian</style></author><author><style face="normal" font="default" size="100%">Jungblut, Anne D.</style></author><author><style face="normal" font="default" size="100%">Mackey, Tyler J.</style></author><author><style face="normal" font="default" size="100%">Eisen, Jonathan A.</style></author><author><style face="normal" font="default" size="100%">Peter T. Doran</style></author><author><style face="normal" font="default" size="100%">Sumner, Dawn Y.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Environmental control on the distribution of metabolic strategies of benthic microbial mats in Lake Fryxell, Antarctica</style></title><secondary-title><style face="normal" font="default" size="100%">PLoS ONE</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2020</style></year><pub-dates><date><style  face="normal" font="default" size="100%">04/2020</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0231053</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">15</style></volume><pages><style face="normal" font="default" size="100%">e0231053</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Ecological theories posit that heterogeneity in environmental conditions greatly affects community structure and function. However, the degree to which ecological theory developed using plant- and animal-dominated systems applies to microbiomes is unclear. Investigating the metabolic strategies found in microbiomes are particularly informative for testing the universality of ecological theories because microorganisms have far wider metabolic capacity than plants and animals. We used metagenomic analyses to explore the relationships between the energy and physicochemical gradients in Lake Fryxell and the metabolic capacity of its benthic microbiome. Statistical analysis of the relative abundance of metabolic marker genes and gene family diversity shows that oxygenic photosynthesis, carbon fixation, and flavin-based electron bifurcation differentiate mats growing in different environmental conditions. The pattern of gene family diversity points to the likely importance of temporal environmental heterogeneity in addition to resource gradients. Overall, we found that the environmental heterogeneity of photosynthetically active radiation (PAR) and oxygen concentration ([O&lt;sub&gt;2&lt;/sub&gt;]) in Lake Fryxell provide the framework by which metabolic diversity and composition of the community is structured, in accordance with its phylogenetic structure. The organization of the resulting microbial ecosystems are consistent with the maximum power principle and the species sorting model.&lt;/p&gt;</style></abstract><issue><style face="normal" font="default" size="100%">4</style></issue></record></records></xml>