Special Seminar "New physiological dimensions of dissimilatory nitrate reduction to ammonium (DNRA)" - Sukhwan Yoon, Ph.D.

Department of Biochemistry and Microbiology

Special Seminar

Speaker: Prof. Sukhwan Yoon, Associate Professor, Department of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology KAIST

Host: Max Haggblom

Abstract:
Dissimilatory nitrate reduction to ammonium (DNRA) is one of the pathways that shape the biogeochemical nitrogen cycle, with growing recognition of its importance in determining the fate of nitrogen in the environment. Using a colorimetry-based high-throughput screening method, we isolated taxonomically diverse DNRA bacteria and, with these new isolates, have explored previously unrecognized or underappreciated aspects of DNRA ecophysiology. We discovered that N2O can inhibit expression of the DNRA nitrite reductase NrfA following oxic-to-anoxic transitions; demonstrated that NrfA-mediated DNRA extends to hydrogen-dependent lithotrophic metabolism; and revisited earlier biochemical hypotheses suggesting a role for NrfA in nitric oxide reduction. Collectively, these findings broaden our understanding of DNRA ecophysiology and point to new opportunities for harnessing this pathway in environmental and ecological engineering to mitigate climate change and nutrient pollution.

"New physiological dimensions of dissimilatory nitrate reduction to ammonium (DNRA)"