{"id":13821,"date":"2019-08-01T11:20:55","date_gmt":"2019-08-01T18:20:55","guid":{"rendered":"https:\/\/www.darkenergybiosphere.org\/?post_type=publication&#038;p=13821"},"modified":"2019-08-16T16:54:02","modified_gmt":"2019-08-16T23:54:02","slug":"diversity-decoupled-from-sulfur-isotope-fractionation-in-a-sulfate%e2%80%90reducing-microbial-community","status":"publish","type":"publication","link":"https:\/\/www.darkenergybiosphere.org\/publication\/diversity-decoupled-from-sulfur-isotope-fractionation-in-a-sulfate%e2%80%90reducing-microbial-community\/","title":{"rendered":"Diversity decoupled from sulfur isotope fractionation in a sulfate\u2010reducing microbial community"},"content":{"rendered":"<p>The extent of fractionation of sulfur isotopes by sulfate\u2010reducing microbes is dictated by genomic and environmental factors. A greater understanding of species\u2010specific fractionations may better inform interpretation of sulfur isotopes preserved in the rock record. To examine whether gene diversity influences net isotopic fractionation in situ, we assessed environmental chemistry, sulfate reduction rates, diversity of putative sulfur\u2010metabolizing organisms by 16S rRNA and dissimilatory sulfite reductase (<i>dsrB<\/i>) gene amplicon sequencing, and net fractionation of sulfur isotopes along a sediment transect of a hypersaline Arctic spring. In situ sulfate reduction rates yielded minimum cell\u2010specific sulfate reduction rates\u00a0&lt;\u00a00.3\u00a0\u00d7\u00a010<sup>\u221215<\/sup>\u00a0moles cell<sup>\u22121<\/sup>\u00a0day<sup>\u22121<\/sup>. Neither 16S rRNA nor\u00a0<i>dsrB<\/i>\u00a0diversity indices correlated with relatively constant (38\u2030\u201345\u2030) net isotope fractionation (\u03b5<sup>34<\/sup>S<sub>sulfide\u2010sulfate<\/sub>). Measured \u03b5<sup>34<\/sup>S values could be reproduced in a mechanistic fractionation model if 1%\u20132% of the microbial community (10%\u201360% of Deltaproteobacteria) were engaged in sulfate respiration, indicating heterogeneous respiratory activity within sulfate\u2010reducing populations. This model indicated enzymatic kinetic diversity of Apr was more likely to correlate with sulfur fractionation than DsrB. We propose that, above a threshold Shannon diversity value of 0.8 for\u00a0<i>dsrB<\/i>, the influence of the specific composition of the microbial community responsible for generating an isotope signal is overprinted by the control exerted by environmental variables on microbial physiology.<\/p>\n","protected":false},"template":"","tags":[],"publication_type":[19],"_links":{"self":[{"href":"https:\/\/www.darkenergybiosphere.org\/wp-json\/wp\/v2\/publication\/13821"}],"collection":[{"href":"https:\/\/www.darkenergybiosphere.org\/wp-json\/wp\/v2\/publication"}],"about":[{"href":"https:\/\/www.darkenergybiosphere.org\/wp-json\/wp\/v2\/types\/publication"}],"wp:attachment":[{"href":"https:\/\/www.darkenergybiosphere.org\/wp-json\/wp\/v2\/media?parent=13821"}],"wp:term":[{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.darkenergybiosphere.org\/wp-json\/wp\/v2\/tags?post=13821"},{"taxonomy":"publication_type","embeddable":true,"href":"https:\/\/www.darkenergybiosphere.org\/wp-json\/wp\/v2\/publication_type?post=13821"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}