title: Biological effects of TiO2and CeO2nanoparticles on the growth, photosynthetic activity, and cellular components of a marine diatom Phaeodactylum tricornutum.
abstract: It is very important to have a good understanding of the biological effects of nanoparticles (NPs) on marine diatoms. In this study, the physiological and biochemical responses of a marine diatom Phaeodactylum tricornutum to titanium dioxide NPs (nano-TiO2) and cerium oxide NPs (nano-CeO2) were compared and evaluated using 96h growth tests in a batch-culture system. At 96h of exposure, the growth inhibition rate (IR, %) of P. tricornutum increased from 5.46 to 27.31% with increasing nano-TiO2concentrations from 2.5 to 40mgL-1. The maximum IR of 49.59% occurred in 40mgL-1nano-TiO2treatments at 48h of exposure. Growth of the diatom was increased in low nano-CeO2treatments (≤5mgL-1), but was inhibited in high nano-CeO2treatments (≥10mgL-1). Large aggregates of NPs were attached to the cells of P. tricornutum in 20 and 40mgL-1nano-TiO2and nano-CeO2treatments. In addition, the effective quantum yields (ΦPSII) of P. tricornutum in 40mgL-1nano-TiO2and nano-CeO2treatments were 83.33 and 71.13% of that in the controls at 96h of exposure, respectively. Compared with that of the controls at 96h of exposure, chlorophyll a content, soluble sugar content, malondialdehyde (MDA) content, SOD and POD activities of P. tricornutum in 40mgL-1nano-TiO2and nano-CeO2treatments increased by 57.56, 142.97, 373.25, 698.76, 204.85% and 21.43, 89.41, 194.97, 340.05, 502.86%, while soluble protein content decreased by 70.38 and 28.64%, respectively. These findings will be helpful to understand the effect mechanisms of NPs on marine organisms.
authors.affiliation: College of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212003, China. Electronic address: dengxy2009@126.com.
authors.forename: Xiang-Yuan
authors.initials: XY
authors.lastname: Deng
authors.affiliation: College of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212003, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Cheng
authors.affiliation: College of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212003, China.
authors.forename: Xiao-Li
authors.initials: XL
authors.lastname: Hu
authors.affiliation: College of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212003, China.
authors.forename: Ling
authors.initials: L
authors.lastname: Wang
authors.affiliation: College of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212003, China.
authors.forename: Da
authors.initials: D
authors.lastname: Li
authors.affiliation: College of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212003, China.
authors.forename: Kun
authors.initials: K
authors.lastname: Gao
mesh_terms: D002563:Cerium / Q000494:pharmacology*; D002734:Chlorophyll; D000077194:Chlorophyll A; D017377:Diatoms / Q000187:drug effects / Q000502:physiology*; D053758:Nanoparticles; D010788:Photosynthesis; D014025:Titanium / Q000494:pharmacology*
chemical_list: D002734:Chlorophyll; C009495:titanium dioxide; D002563:Cerium; C030583:ceric oxide; D014025:Titanium; D000077194:Chlorophyll A
keywords: Biochemical responses; Growth inhibition; Nano-CeO(2); Nano-TiO(2); Phaeodactylum tricornutum; Photosynthetic activity