title: Toxicity and internalization of CuO nanoparticles to prokaryotic alga Microcystis aeruginosa as affected by dissolved organic matter.
abstract: This is the first study investigating the toxicity of nanoparticles (NPs) to algae in the presence of dissolved organic matter (DOM). Suwannee river fulvic acid (SRFA), a type of DOM, could significantly increase the toxicity of CuO NPs to prokaryotic alga Microcystis aeruginosa. Internalization of CuO NPs was observed for the first time in the intact algal cells using high resolution transmission electron microscopy (HRTEM), and the cell uptake was enhanced by SRFA. A fast Fourier transformation (FFT)/inversed FFT (IFFT) process revealed that a main form of intracellular NPs was Cu(2)O, and an intracellular environment may reduce CuO into Cu(2)O. The internalization behavior alone did not seem to pose a hazard to membrane integrity as shown from the flow cytometry data. Elevated CuO nanotoxicity by SRFA was related to a combination of a lesser degree of aggregation, higher Cu(2+) release, and enhanced internalization of CuO NPs.
authors.affiliation: College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China.
authors.forename: Zhenyu
authors.initials: Z
authors.lastname: Wang
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.forename: Jian
authors.initials: J
authors.lastname: Zhao
authors.forename: Baoshan
authors.initials: B
authors.lastname: Xing
mesh_terms: D001578:Benzopyrans; D002462:Cell Membrane / Q000378:metabolism; D020552:Comet Assay; D003300:Copper / Q000737:chemistry* / Q000633:toxicity; D004249:DNA Damage; D005434:Flow Cytometry; D005583:Fourier Analysis; D006812:Humic Substances / Q000032:analysis*; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000633:toxicity; D046931:Microcystis / Q000378:metabolism*; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D008958:Models, Molecular; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D001578:Benzopyrans; D006812:Humic Substances; D017382:Reactive Oxygen Species; D003300:Copper; C030973:cupric oxide; C005023:fulvic acid