Biofilms attached to Myriophyllum spicatum play a dominant role in nitrogen removal in constructed wetland mesocosms with submersed macrophytes: Evidence from 15N tracking, nitrogen budgets and metagenomics analyses. (November 2020)

• Record Type: Journal Article
• Authors: Mu, Xiaoying; Lv, Xiaoyang; Liu, Wei; Qiu, Changhao; Ma, Yu; Zhang, Songhe; Jeppesen, Erik
• Is Part Of: Environmental pollution. Volume 266:Part 2(2020)
• Publication Date: 2020-11
• Subjects: Submersed macrophyte -- Biofilms -- Ammonium -- Nitrification -- Denitrification -- Nitrogen cycle-related genes; Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2020.115203
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: 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. 15 N tracking showed that 61.9% and 30% of the 15 N, respectively, was removed from the system and assimilated by the macrophyte-biofilm complex after loading with 5.4 mg L −1 15 N 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. Graphical abstract: Image 1 Highlights: M. spicatum restoration promoted nitrogen removal in constructed wetlands (mesocosm scale). The biofilms had a higher competitiveness for waterborne nitrogen than M. spicatum. Bacteria were the most dominant domain, followed by eukaryotes, archaea and viruses. There were complex interactions among nitrogen-cycling genes and genera. Abstract : The biofilms had a higher competitiveness for nitrogen than M. spicatum and there were complex interactions among nitrogen-cycling genes and genera in biofilms.