High-throughput pyrosequencing analysis of bacteria relevant to cometabolic and metabolic degradation of ibuprofen in horizontal subsurface flow constructed wetlands.
The potential toxicity of pharmaceutical residues including ibuprofen on the aquatic vertebrates and invertebrates has attracted growing attention to the pharmaceutical pollution control using constructed wetlands, but there lacks of an insight into the relevant microbial degradation mechanisms. This study investigated the bacteria associated with the cometabolic and metabolic degradation of ibuprofen in a horizontal subsurface flow constructed wetland system by high-throughput pyrosequencing analysis. The ibuprofen degradation dynamics, bacterial diversity and evenness, and bacterial community structure in a planted bed with Typha angustifolia and an unplanted bed (control) were compared. The results showed that the plants promoted the microbial degradation of ibuprofen, especially at the downstream zones of wetland. However, at the upstream one-third zone of wetland, the presence of plants did not significantly enhance ibuprofen degradation, probably due to the much greater contribution of cometabolic behaviors of certain non-ibuprofen-degrading microorganisms than that of the plants. By analyzing bacterial characteristics, we found that: (1) The aerobic species of family Flavobacteriaceae, family Methylococcaceae and genus Methylocystis, and the anaerobic species of family Spirochaetaceae and genus Clostridium_sensu_stricto were the most possible bacteria relevant to the cometabolic degradation of ibuprofen; (2) The family Rhodocyclaceae and the genus Ignavibacterium closely related to the plants appeared to be associated with the metabolic degradation of ibuprofen.
School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798, Singapore; Advanced Environmental Biotechnology Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, CleanTech One, 637141, Singapore. Electronic address: yli19@e.ntu.edu.sg.
Yifei
Y
Li
Singapore Membrane Technology Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, CleanTech One, 637141, Singapore.
Bing
B
Wu
State Key Laboratory of Environmental Aquatic Quality, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 100085, PR China. Electronic address: gbzhu@rcees.ac.cn.
Guibing
G
Zhu
School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798, Singapore; Advanced Environmental Biotechnology Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, CleanTech One, 637141, Singapore.
Yu
Y
Liu
School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798, Singapore; Nanyang Environment and Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, CleanTech One, 637141, Singapore.
Wun Jern
WJ
Ng
Nanyang Environment and Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, CleanTech One, 637141, Singapore.
Adhityan
A
Appan
School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798, Singapore; Nanyang Environment and Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, CleanTech One, 637141, Singapore; Maritime Research Centre, Nanyang Technological University, 50 Nanyang Avenue, 639798, Singapore.
Soon Keat
SK
Tan
D001419:Bacteria / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D001673:Biodegradation, Environmental; D007052:Ibuprofen / Q000378:metabolism*; D014865:Waste Disposal, Fluid / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000378:metabolism*; D053833:Wetlands
D014874:Water Pollutants, Chemical; D007052:Ibuprofen
Horizontal subsurface flow constructed wetland; Ibuprofen; Macrophyte; Microorganism; Organic micropollutant