Community Composition of Nitrous Oxide-Related Genes in Salt Marsh Sediments Exposed to Nitrogen Enrichment

Frontiers in Microbiology

Patrick J. Kearns¹  Ian Craick¹  Jennifer L. Bowen¹  John H. Angell¹  Qixing Ji²  Xuefeng Peng²  Amal Jayakumar²  Bess B. Ward² 

[1] Biology Department, University of Massachusetts Boston, Boston, MA, United States;Department of Geosciences, Princeton University, Princeton, NJ, United States;

关键词: salt marsh;    nitrous oxide;    nutrient enrichment;    denitrification;    norB;    nosZ;   

DOI  :  10.3389/fmicb.2018.00170

来源: DOAJ

【 摘 要 】

Salt marshes provide many key ecosystem services that have tremendous ecological and economic value. One critical service is the removal of fixed nitrogen from coastal waters, which limits the negative effects of eutrophication resulting from increased nutrient supply. Nutrient enrichment of salt marsh sediments results in higher rates of nitrogen cycling and, commonly, a concurrent increase in the flux of nitrous oxide, an important greenhouse gas. Little is known, however, regarding controls on the microbial communities that contribute to nitrous oxide fluxes in marsh sediments. To address this disconnect, we generated profiles of microbial communities and communities of micro-organisms containing specific nitrogen cycling genes that encode several enzymes (amoA, norB, nosZ) related to nitrous oxide flux from salt marsh sediments. We hypothesized that communities of microbes responsible for nitrogen transformations will be structured by nitrogen availability. Taxa that respond positively to high nitrogen inputs may be responsible for the elevated rates of nitrogen cycling processes measured in fertilized sediments. Our data show that, with the exception of ammonia-oxidizing archaea, the community composition of organisms involved in the production and consumption of nitrous oxide was altered under nutrient enrichment. These results suggest that previously measured rates of nitrous oxide production and consumption are likely the result of changes in community structure, not simply changes in microbial activity.

【 授权许可】

Unknown