title: Effects of low molecular-weight organic acids and dehydrogenase activity in rhizosphere sediments of mangrove plants on phytoremediation of polycyclic aromatic hydrocarbons.
abstract: This work evaluated the roles of the low-molecular-weight organic acids (LMWOAs) from root exudates and the dehydrogenase activity in the rhizosphere sediments of three mangrove plant species on the removal of mixed PAHs. The results showed that the concentrations of LMWOAs and dehydrogenase activity changed species-specifically with the levels of PAH contamination. In all plant species, the concentration of citric acid was the highest, followed by succinic acid. For these acids, succinic acid was positively related to the removal of all the PAHs except Chr. Positive correlations were also found between the removal percentages of 4-and 5-ring PAHs and all LMWOAs, except citric acid. LMWOAs enhanced dehydrogenase activity, which positively related to PAH removal percentages. These findings suggested that LMWOAs and dehydrogenase activity promoted the removal of PAHs. Among three mangrove plants, Bruguiera gymnorrhiza, the plant with the highest root biomass, dehydrogenase activity and concentrations of LMWOAs, was most efficient in removing PAHs.
authors.affiliation: MOE Key Laboratory of Aquatic Product Safety, Key Laboratory of Biodiversity Dynamics and Conservation of Guangdong Higher Education Institute, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China; Department of Biology and Chemistry, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, China.
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Wang
authors.affiliation: MOE Key Laboratory of Aquatic Product Safety, Key Laboratory of Biodiversity Dynamics and Conservation of Guangdong Higher Education Institute, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China.
authors.forename: Ling
authors.initials: L
authors.lastname: Fang
authors.affiliation: MOE Key Laboratory of Aquatic Product Safety, Key Laboratory of Biodiversity Dynamics and Conservation of Guangdong Higher Education Institute, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China. Electronic address: linl@mail.sysu.edu.cn.
authors.forename: Li
authors.initials: L
authors.lastname: Lin
authors.affiliation: MOE Key Laboratory of Aquatic Product Safety, Key Laboratory of Biodiversity Dynamics and Conservation of Guangdong Higher Education Institute, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China; Department of Biology and Chemistry, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, China.
authors.forename: Tiangang
authors.initials: T
authors.lastname: Luan
authors.affiliation: Department of Biology and Chemistry, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, China; State Key Laboratory in Marine Pollution, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, China. Electronic address: bhntam@cityu.edu.hk.
authors.forename: Nora F Y
authors.initials: NF
authors.lastname: Tam
mesh_terms: D000143:Acids / Q000737:chemistry; D001673:Biodegradation, Environmental; D018533:Biomass; D008970:Molecular Weight; D009930:Organic Chemicals; D010088:Oxidoreductases / Q000032:analysis / Q000378:metabolism*; D018517:Plant Roots / Q000737:chemistry; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis / Q000378:metabolism*; D043982:Rhizophoraceae / Q000378:metabolism; D058441:Rhizosphere; D012988:Soil Microbiology; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000378:metabolism*; D053833:Wetlands
chemical_list: D000143:Acids; D009930:Organic Chemicals; D011084:Polycyclic Aromatic Hydrocarbons; D014874:Water Pollutants, Chemical; D010088:Oxidoreductases
keywords: Mangrove; Organic acids; PAHs; Remediation; Root exudate