title: Assessment of agglomeration, co-sedimentation and trophic transfer of titanium dioxide nanoparticles in a laboratory-scale predator-prey model system.
abstract: Nano titanium dioxide (nTiO2) is the most abundantly released engineered nanomaterial (ENM) in aquatic environments. Therefore, it is prudent to assess its fate and its effects on lower trophic-level organisms in the aquatic food chain. A predator-and-prey-based laboratory microcosm was established using Paramecium caudatum and Escherichia coli to evaluate the effects of nTiO2. The surface interaction of nTiO2 with E. coli significantly increased after the addition of Paramecium into the microcosm. This interaction favoured the hetero-agglomeration and co-sedimentation of nTiO2. The extent of nTiO2 agglomeration under experimental conditions was as follows: combined E. coli and Paramecium > Paramecium only > E. coli only > without E. coli or Paramecium. An increase in nTiO2 internalisation in Paramecium cells was also observed in the presence or absence of E. coli cells. These interactions and nTiO2 internalisation in Paramecium cells induced statistically significant (p < 0.05) effects on growth and the bacterial ingestion rate at 24 h. These findings provide new insights into the fate of nTiO2 in the presence of bacterial-ciliate interactions in the aquatic environment.
authors.affiliation: Division of Biological &Life Sciences, School of Arts &Sciences (Formerly, Institute of Life Sciences), Ahmedabad University, University Road, Navrangpura, Ahmedabad - 380009, Gujarat (India).|Nanotherapeutics &Nanomaterial Toxicology Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), Vishvigyan Bhawan, 31-M.G. Marg, Lucknow - 226001, U.P. (India).
authors.forename: Govind Sharan
authors.initials: GS
authors.lastname: Gupta
authors.affiliation: Division of Biological &Life Sciences, School of Arts &Sciences (Formerly, Institute of Life Sciences), Ahmedabad University, University Road, Navrangpura, Ahmedabad - 380009, Gujarat (India).
authors.forename: Ashutosh
authors.initials: A
authors.lastname: Kumar
authors.affiliation: Division of Biological &Life Sciences, School of Arts &Sciences (Formerly, Institute of Life Sciences), Ahmedabad University, University Road, Navrangpura, Ahmedabad - 380009, Gujarat (India).
authors.forename: Rishi
authors.initials: R
authors.lastname: Shanker
authors.affiliation: Nanotherapeutics &Nanomaterial Toxicology Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), Vishvigyan Bhawan, 31-M.G. Marg, Lucknow - 226001, U.P. (India).
authors.forename: Alok
authors.initials: A
authors.lastname: Dhawan
mesh_terms: D004926:Escherichia coli / Q000378:metabolism*; D020387:Food Chain; D008954:Models, Biological; D049329:Nanostructures; D048488:Paramecium caudatum / Q000378:metabolism*; D014025:Titanium / Q000378:metabolism*
chemical_list: C009495:titanium dioxide; D014025:Titanium