title: Examining the impact of acetylene on N-fixation and the active sediment microbial community.
abstract: Here we examined the impact of a commonly employed method used to measure nitrogen fixation, the acetylene reduction assay (ARA), on a marine sediment community. Historically, the ARA technique has been broadly employed for its ease of use, in spite of numerous known artifacts. To gauge the severity of these effects in a natural environment, we employed high-throughput 16S rRNA gene sequencing to detect differences in acetylene-treated sediments vs. non-treated control sediments after a 7 h incubation. Within this short time period, significant differences were seen across all activity of microbes identified in the sediment, implying that the changes induced by acetylene occur quickly. The results have important implications for our understanding of marine nitrogen budgets. Moreover, because the ARA technique has been widely used in terrestrial and freshwater habitats, these results may be applicable to other ecosystems.
authors.affiliation: Department of Earth and Environment, Boston University Boston, MA, USA ; Department of Biology, Boston University Boston, MA, USA.
authors.forename: Robinson W
authors.initials: RW
authors.lastname: Fulweiler
authors.affiliation: Department of Earth and Environment, Boston University Boston, MA, USA ; Department of Chemistry and Physics, King's College Wilkes-Barre, PA, USA.
authors.forename: Elise M
authors.initials: EM
authors.lastname: Heiss
authors.affiliation: Department of Earth and Environment, Boston University Boston, MA, USA ; Department of Marine Sciences, University of Georgia Athens, GA, USA.
authors.forename: Mary Kate
authors.initials: MK
authors.lastname: Rogener
authors.affiliation: Department of Earth and Environment, Boston University Boston, MA, USA ; Department of Earth and Environmental Sciences, Wright State University Dayton, OH, USA.
authors.forename: Silvia E
authors.initials: SE
authors.lastname: Newell
authors.affiliation: Department of Microbiology, University of Tennessee Knoxville, TN, USA.
authors.forename: Gary R
authors.initials: GR
authors.lastname: LeCleir
authors.affiliation: Department of Microbiology, University of Tennessee Knoxville, TN, USA.
authors.forename: Sarah M
authors.initials: SM
authors.lastname: Kortebein
authors.affiliation: Department of Microbiology, University of Tennessee Knoxville, TN, USA.
authors.forename: Steven W
authors.initials: SW
authors.lastname: Wilhelm
keywords: acetylene reduction assay; heterotrophic nitrogen fixation; high throughput sequencing; sediments; sulfate-reducing bacteria