title: Effect of enhanced reactive nitrogen availability on plant-sediment mediated degradation of polycyclic aromatic hydrocarbons in contaminated mangrove sediment.
abstract: As land-ocean interaction zones, mangrove systems receive substantial polycyclic aromatic hydrocarbons (PAHs) from sewage and combustion of fossil fuel. In this study, we investigated the relationship between dissolved inorganic nitrogen (DIN) availability and degradation rate of phenanthrene, a typical PAH compound, in mangrove plant-sediment systems, using Avicennia marina as a model plant. After 50 day incubation, phenanthrene removal ratios in sediments ranged from 53.8% to 97.2%. In non-rhizosphere sediment, increasing DIN accessibility increased microbial biomass and total microbial activity, while enhancements in population size of phenanthrene degradation bacteria (PDB) and phenanthrene degradation rates were insignificant. In contrast, the presence of excessive DIN in rhizosphere sediment resulted in a significantly large number of PDB, leading to a rapid dissipation rate of phenanthrene. The differences in degradation rates and abundances of degrader in sediment may be explained by the enhanced root activity due to the elevation in DIN accessibility.
authors.affiliation: Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen University, 361005, China.
authors.forename: Shan
authors.initials: S
authors.lastname: Jiang
authors.affiliation: Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen University, 361005, China.
authors.forename: Haoliang
authors.initials: H
authors.lastname: Lu
authors.affiliation: Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen University, 361005, China; School of Biological Sciences and Biotechnology, Minnan Normal University, 363000, China.
authors.forename: Qiong
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen University, 361005, China.
authors.forename: JingChun
authors.initials: J
authors.lastname: Liu
authors.affiliation: Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen University, 361005, China. Electronic address: ycl@xmu.edu.cn.
authors.forename: Chongling
authors.initials: C
authors.lastname: Yan
mesh_terms: D032407:Avicennia / Q000378:metabolism* / Q000382:microbiology; D001419:Bacteria / Q000378:metabolism; D001673:Biodegradation, Environmental; D018533:Biomass; D019015:Geologic Sediments / Q000382:microbiology; D009584:Nitrogen / Q000378:metabolism*; D010616:Phenanthrenes / Q000032:analysis / Q000378:metabolism*; D018517:Plant Roots / Q000737:chemistry; D058441:Rhizosphere; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000378:metabolism*; D053833:Wetlands
chemical_list: D010616:Phenanthrenes; D014874:Water Pollutants, Chemical; C031181:phenanthrene; D009584:Nitrogen
keywords: DIN; Degradation; Enhancement; Mangrove wetland; PAHs