title: Cumulative effect of zinc oxide and titanium oxide nanoparticles on growth and chlorophyll a content of Picochlorum sp.
abstract: The use of nanoparticles (NPs) is of increasing significance due to their large potential for various applications. Great attention should be paid on the possible impacts of nanoparticles on the environment as large amounts of them may reach the environment by accident or voluntarily. Marine algae are potential organisms for usage in nanopollution bioremediation in aquatic system, because of their ability to adapt to long exposure to NPs. Thus, it is of prime importance to study the possible interactions of different NPs with microalgae in assessing their potential environmental risks. Most studies on potential environmental effects of ZnO and TiO2 NPs have been performed independently and following the widely accepted, standardized test systems, which had been developed for the characterization of chemicals. In this study, we have examined the cumulative effect of ZnO and TiO2 NPs on Picochlorum sp. in addition to the individual effects of these NPs over 32 days. Our results indicate that the toxicity and availability of NPs to marine algae are reduced by their aggregation and sedimentation. NPs are found to have a negative effect on algal growth and chlorophyll a concentration during the early growth stages. In contrast, the case is reversed during the late growth stages. There is no significant difference between the effect of the NPs when they are used separately and when both ZnO and TiO2 are used together in the test (P > 0.05).
authors.affiliation: Department of Biology, College of Science, University of Bahrain, PO Box 32038, Manama, Kingdom of Bahrain. lhazeem@uob.edu.bh.
authors.forename: Layla J
authors.initials: LJ
authors.lastname: Hazeem
authors.affiliation: Nanotechnology Centre, University of Bahrain, PO Box 32038, Manama, Kingdom of Bahrain.|Department of Physics, College of Science, University of Bahrain, PO Box 32038, Manama, Kingdom of Bahrain.
authors.forename: Mohammed
authors.initials: M
authors.lastname: Bououdina
authors.affiliation: Department of Chemistry, College of Science, University of Bahrain, PO Box 32038, Manama, Kingdom of Bahrain.
authors.forename: Suad
authors.initials: S
authors.lastname: Rashdan
authors.affiliation: BioImaging Center of Lille, Université Lille 1, 59655, Villeneuve d'Ascq Cedex, France.
authors.forename: Loïc
authors.initials: L
authors.lastname: Brunet
authors.affiliation: Inserm U1003, Laboratoire de Physiologie Cellulaire, Université Lille 1, 59655, Villeneuve d'Ascq Cedex, France.
authors.forename: Christian
authors.initials: C
authors.lastname: Slomianny
authors.affiliation: Institut d'Electronique, de Microélectronique et de Nanotechnologie (IEMN), CNRS UMR 8520, Université Lille 1, Avenue Poincaré, BP 60069, 59652, Villeneuve d'Ascq Cedex, France.
authors.forename: Rabah
authors.initials: R
authors.lastname: Boukherroub
mesh_terms: D002734:Chlorophyll / Q000378:metabolism*; D000077194:Chlorophyll A; D000460:Chlorophyta / Q000187:drug effects* / Q000254:growth & development* / Q000378:metabolism; D053758:Nanoparticles / Q000737:chemistry / Q000633:toxicity*; D014025:Titanium / Q000032:analysis / Q000378:metabolism* / Q000633:toxicity; D015034:Zinc Oxide / Q000032:analysis / Q000378:metabolism* / Q000633:toxicity
chemical_list: D002734:Chlorophyll; C009495:titanium dioxide; D014025:Titanium; D015034:Zinc Oxide; D000077194:Chlorophyll A
keywords: Chlorophyll a; Nanoparticles; Picochlorum sp.; TiO2; Viable cells; ZnO