Physical Sciences and Mathematics Commons^™

Denitrification By Sulfur-Oxidizing Bacteria In A Eutrophic Lake, Amy J. Burgin, Stephen K. Hamilton, Stuart E. Jones, Jay T. Lennon

School of Natural Resources: Faculty Publications

Understanding the mechanistic controls of microbial denitrification is of central importance to both environmental microbiology and ecosystem ecology. Loss of nitrate (NO₃ ⁻) is often attributed to carbon-driven (heterotrophic) denitrification. However, denitrification can also be coupled to sulfur (S) oxidation by chemolithoautotrophic bacteria. In the present study, we used an in situ stable isotope (¹⁵NO₃ ⁻) tracer addition in combination with molecular approaches to understand the contribution of sulfur-oxidizing bacteria to the reduction of NO3 ⁻ in a eutrophic lake. Samples were incubated across a total dissolved sulfide (H₂S) gradient (2 to …