title: Laboratory Scale Microbial Food Chain To Study Bioaccumulation, Biomagnification, and Ecotoxicity of Cadmium Telluride Quantum Dots.
abstract: The increasing applications of engineered nanomaterials (ENMs) in consumer products warrant a careful evaluation of their trophic transfer and consequent ecological impact. In the present study, a laboratory scale aquatic microbial food chain was established using bacteria (Escherichia coli (E. coli)) as a prey and ciliated protozoan (Paramecium caudatum) as a predator organism to determine the impact of cadmium telluride quantum dots (CdTe QDs). We observed that 29% of bacterivory potential of paramecium was lost, including an ∼12 h delay in doubling time on exposure to 25 mg/L CdTe QD (∼4 nm) as compared to control. The fluorescence based stoichiometric analysis revealed that 65% of the QDs bioaccumulated when paramecia were exposed to 25 mg/L QDs at 24 h. There was a significant (p < 0.05) increase in cellular cadmium (Cd) concentration at 24 h (306 ± 192 mg/L) as compared to 1 h (152 ± 50 mg/L). Moreover, the accumulation of Cd in E. coli (147 ± 25 mg/L) at 1 h of exposure to 25 mg/L QDs transferred 1.4 times higher Cd (207 ± 24 mg/L; biomagnification factor = 1.4) to its predator, paramecium.
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 Mahatma Gandhi Marg, P. O. Box 80, Lucknow 226001, Uttar Pradesh, India.
authors.forename: Govind S
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: Violet A
authors.initials: VA
authors.lastname: Senapati
authors.affiliation: Nanotherapeutics & Nanomaterial Toxicology Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR) , Vishvigyan Bhawan, 31 Mahatma Gandhi Marg, P. O. Box 80, Lucknow 226001, Uttar Pradesh, India.
authors.forename: Alok K
authors.initials: AK
authors.lastname: Pandey
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 Mahatma Gandhi Marg, P. O. Box 80, Lucknow 226001, Uttar Pradesh, India.
authors.forename: Alok
authors.identifier: 0000-0002-4405-9608
authors.initials: A
authors.lastname: Dhawan
mesh_terms: D002104:Cadmium / Q000633:toxicity; D019187:Cadmium Compounds / Q000633:toxicity; D004926:Escherichia coli; D020387:Food Chain; D049329:Nanostructures; D010247:Paramecium; D045663:Quantum Dots / Q000633:toxicity*; D013691:Tellurium / Q000633:toxicity
chemical_list: D019187:Cadmium Compounds; D002104:Cadmium; D013691:Tellurium