title: Toxicity of perfluorooctanoic acid to Pseudomonas putida in the aquatic environment.
abstract: Perfluorinated compounds are potential persistent organic pollutants which attracted much concerns in recent years. Thus relevant toxicity data of perfluorooctanoic acid (PFOA) are vitally important for identification of possible risk in the aquatic environment. In the present study, the acute toxic effect of PFOA in the absence and presence of either chromium (III) or tetra butyl ammonium (TBA) towards Pseudomonas putida in the aquatic environment was investigated by microcalorimetry. The thermokinetic parameters including growth rate constant (k), inhibitory ratio, and half inhibitory concentration, were calculated and compared using the data obtained from the power-time curves. Our work revealed the toxicity of PFOA under three experimental conditions in a descending sequence: PFOA, PFOA+Cr(3+), and PFOA+TBA. The results highlighted that the presence of un-ionized NH3 in the test solutions could not be a potential significant contributor to the observed toxicity of PFOA. In addition, PFOA interacted antagonistically with Cr(3+) and TBA. TBA was found to substantially enhance the surface pressure of PFOA which could be related with the toxicity of PFOA. The higher surface pressure caused for the reduction in toxicity. Thus the results highlighted the potential toxicological risk associated with this surfactant in the aquatic ecosystems.
authors.affiliation: School of Civil & Environmental Engineering, and National International Cooperation Base on Environment and Energy, University of Science and Technology Beijing, 30 Xueyuan Road, 100083 Beijing, PR China.
authors.forename: Huilun
authors.initials: H
authors.lastname: Chen
authors.forename: Jun
authors.initials: J
authors.lastname: Yao
authors.forename: Fei
authors.initials: F
authors.lastname: Wang
authors.forename: Minmin
authors.initials: M
authors.lastname: Cai
authors.forename: Haijun
authors.initials: H
authors.lastname: Liu
mesh_terms: D002210:Caprylates / Q000737:chemistry / Q000633:toxicity*; D002857:Chromium / Q000737:chemistry; D005466:Fluorocarbons / Q000737:chemistry / Q000633:toxicity*; D016958:Pseudomonas putida / Q000187:drug effects* / Q000254:growth & development; D000644:Quaternary Ammonium Compounds / Q000737:chemistry; D013501:Surface-Active Agents / Q000737:chemistry / Q000633:toxicity*; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000633:toxicity*
chemical_list: D002210:Caprylates; D005466:Fluorocarbons; D000644:Quaternary Ammonium Compounds; D013501:Surface-Active Agents; D014874:Water Pollutants, Chemical; D002857:Chromium; C023036:perfluorooctanoic acid; C009405:tetrabutylammonium
keywords: Acute toxicity; Antagonism; Microcalorimetry; PFOA; Surface pressure