The vertical partitioning between denitrification and dissimilatory nitrate reduction to ammonium of coastal mangrove sediment microbiomes.

Mangrove aquatic ecosystems receive substantial nitrogen (N) inputs from both land and sea, playing critical roles in modulating coastal N fluxes. The microbially-mediated competition between denitrification and dissimilatory nitrate reduction to ammonium (DNRA) in mangrove sediments significantly impacts the N fate and transformation processes. Despite their recognized role in N loss or retention in surface sediments, how these two processes vary with sediment depths and their influential factors remain elusive.

Effects of marine produced organic matter on the potential estuarine capacity of NO removal.

Dissolved inorganic nitrogen (DIN) is very high in the Pearl River Estuary (PRE) and nitrate (NO) removal processes such as denitrification, anaerobic ammonium oxidation (anammox) and dissimilatory nitrate reduction to ammonium (DNRA) are important for determining export of DIN to coastal waters. However, fluxes of NO removal and influencing factors in the PRE are still unclear. We conducted 4 cruises at 11 sites in the PRE to investigate potential NO removal rates, their contributions, and corresponding gene abundances, and controlling factors in surface sediments (0-5 cm).