Biofilms attached to Myriophyllum spicatum play a dominant role in nitrogen removal in constructed wetland mesocosms with submersed macrophytes: Evidence from N-15 tracking, nitrogen budgets and metagenomics analyses


Mu X., Lv X., Liu W., Qiu C., Ma Y., Zhang S., ...Daha Fazla

ENVIRONMENTAL POLLUTION, cilt.266, 2020 (SCI İndekslerine Giren Dergi) identifier identifier identifier

Özet

The mechanisms behind nitrogen removal by the submersed macrophyte-biofilm complex in wetlands remain to be fully elucidated. This study investigated the role of Myriophyllum spicatum and the biofilm on their leaves in nitrogen removal in mesocosm experiments. N-15 tracking showed that 61.9% and 30% of the N-15, respectively, was removed from the system and assimilated by the macrophyte-biofilm complex after loading with 5.4 mg L-1 N-15 labelled NH4+ for 17 days. Nitrogen budget results showed that about 0.2%, 0.2% and 3.6% of the nitrogen were emitted as water-, HCl- and NaOH-soluble nitrogen-gas species, respectively. Bacteria (76.7-91.8%) were the predominant domain in all samples, followed by eukaryotes (8.0-23.0%), archaea and viruses. Network analyses showed that there were positive- and negative-correlative relationships among nitrogen-cycling genes and nitrifiers and denitrifiers. Our data highlight the important role of biofilm on submersed macrophytes for nitrogen removal. (C) 2020 Elsevier Ltd. All rights reserved.