title: Impact of carbon nanotubes on the ingestion and digestion of bacteria by ciliated protozoa.
abstract: Research on the toxicity of carbon nanotubes has focused on human health risks, and little is known about their impact on natural ecosystems. The ciliated protozoan Tetrahymena thermophila has been widely studied by ecotoxicologists because of its role in the regulation of microbial populations through the ingestion and digestion of bacteria, and because it is an important organism in wastewater treatment and an indicator of sewage effluent quality. Here we show that single-walled carbon nanotubes are internalized by T. thermophila, possibly allowing the nanotubes to move up the food chain. The internalization also causes the protozoa to aggregate, which impedes their ability to ingest and digest their prey bacteria species, although it might also be possible to use nanotubes to improve the efficiency of wastewater treatment.
authors.affiliation: Department of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada.
authors.forename: Parnian
authors.initials: P
authors.lastname: Ghafari
authors.forename: Christine H
authors.initials: CH
authors.lastname: St-Denis
authors.forename: Mary E
authors.initials: ME
authors.lastname: Power
authors.forename: Xu
authors.initials: X
authors.lastname: Jin
authors.forename: Veronica
authors.initials: V
authors.lastname: Tsou
authors.forename: Himadri S
authors.initials: HS
authors.lastname: Mandal
authors.forename: Niels C
authors.initials: NC
authors.lastname: Bols
authors.forename: Xiaowu Shirley
authors.initials: XS
authors.lastname: Tang
mesh_terms: D000818:Animals; D004435:Eating / Q000187:drug effects* / Q000502:physiology*; D037742:Nanotubes, Carbon / Q000633:toxicity*; D016808:Tetrahymena thermophila / Q000187:drug effects* / Q000382:microbiology* / Q000502:physiology
chemical_list: D037742:Nanotubes, Carbon