title: Evaluation of cytotoxic and antimicrobial effects of two Bt Cry proteins on a GMO safety perspective.
abstract: Studies have contested the innocuousness of Bacillus thuringiensis (Bt) Cry proteins to mammalian cells as well as to mammals microbiota. Thus, this study aimed to evaluate the cytotoxic and antimicrobial effects of two Cry proteins, Cry8Ka5 (a novel mutant protein) and Cry1Ac (a widely distributed protein in GM crops). Evaluation of cyto- and genotoxicity in human lymphocytes was performed as well as hemolytic activity coupled with cellular membrane topography analysis in mammal erythrocytes. Effects of Cry8Ka5 and Cry1Ac upon Artemia sp. nauplii and upon bacteria and yeast growth were assessed. The toxins caused no significant effects on the viability (IC50 > 1,000 µg/mL) or to the cellular DNA integrity of lymphocytes (no effects at 1,000 µg/mL). The Cry8Ka5 and Cry1Ac proteins did not cause severe damage to erythrocytes, neither with hemolysis (IC50 > 1,000 µg/mL) nor with alterations in the membrane. Likewise, the Cry8Ka5 and Cry1Ac proteins presented high LC50 (755.11 and >1,000 µg/mL, resp.) on the brine shrimp lethality assay and showed no growth inhibition of the microorganisms tested (MIC > 1,000 µg/mL). This study contributed with valuable information on the effects of Cry8Ka5 and Cry1Ac proteins on nontarget organisms, which reinforce their potential for safe biotechnological applications.
authors.affiliation: Graduate Program in Biochemistry, Federal University of Ceará, 60440-900 Fortaleza, CE, Brazil.
authors.forename: Davi Felipe
authors.initials: DF
authors.lastname: Farias
authors.affiliation: Graduate Program in Biochemistry, Federal University of Ceará, 60440-900 Fortaleza, CE, Brazil.
authors.forename: Martônio Ponte
authors.initials: MP
authors.lastname: Viana
authors.affiliation: Graduate Program in Bioprocess Engineering and Biotechnology, Federal University of Paraná, P.O. Box 19011, 81531-98 Curitiba, PR, Brazil ; National Center of Genetic Resources (Embrapa-Cenargen), Parque Estação Biológica-PqEB-Avenida, W5 Norte (Final), P.O. Box 02372, 70770-917 Brasília, DF, Brazil.
authors.forename: Gustavo Ramos
authors.initials: GR
authors.lastname: de Oliveira
authors.affiliation: National Center of Genetic Resources (Embrapa-Cenargen), Parque Estação Biológica-PqEB-Avenida, W5 Norte (Final), P.O. Box 02372, 70770-917 Brasília, DF, Brazil.
authors.forename: Magda Aparecida
authors.initials: MA
authors.lastname: Beneventi
authors.affiliation: Graduate Program in Pharmacology, Federal University of Ceará, 60430-270 Fortaleza, CE, Brazil.
authors.forename: Bruno Marques
authors.initials: BM
authors.lastname: Soares
authors.affiliation: Graduate Program in Pharmacology, Federal University of Ceará, 60430-270 Fortaleza, CE, Brazil.
authors.forename: Claudia
authors.initials: C
authors.lastname: Pessoa
authors.affiliation: Graduate Program in Biochemistry, Federal University of Ceará, 60440-900 Fortaleza, CE, Brazil.
authors.forename: Igor Parra
authors.initials: IP
authors.lastname: Pessoa
authors.affiliation: National Center of Genetic Resources (Embrapa-Cenargen), Parque Estação Biológica-PqEB-Avenida, W5 Norte (Final), P.O. Box 02372, 70770-917 Brasília, DF, Brazil.
authors.forename: Luciano Paulino
authors.initials: LP
authors.lastname: Silva
authors.affiliation: Graduate Program in Biochemistry, Federal University of Ceará, 60440-900 Fortaleza, CE, Brazil.
authors.forename: Ilka Maria
authors.initials: IM
authors.lastname: Vasconcelos
authors.affiliation: National Center of Genetic Resources (Embrapa-Cenargen), Parque Estação Biológica-PqEB-Avenida, W5 Norte (Final), P.O. Box 02372, 70770-917 Brasília, DF, Brazil ; Graduate Program in Gemonics Sciences and Biotechnology, Catholic University of Brasília, SGAN Quadra 916, Módulo B, W5 Norte, Asa Norte, 70790-160 Brasília, DF, Brazil.
authors.forename: Maria Fátima Grossi
authors.initials: MF
authors.lastname: de Sá
authors.affiliation: Graduate Program in Biochemistry, Federal University of Ceará, 60440-900 Fortaleza, CE, Brazil.
authors.forename: Ana Fontenele Urano
authors.initials: AF
authors.lastname: Carvalho
mesh_terms: D000818:Animals; D001156:Artemia / Q000187:drug effects; D001413:Bacillus thuringiensis / Q000737:chemistry / Q000235:genetics*; D000083722:Bacillus thuringiensis Toxins; D001419:Bacteria / Q000187:drug effects; D001426:Bacterial Proteins / Q000008:administration & dosage / Q000235:genetics*; D049109:Cell Proliferation / Q000187:drug effects; D004731:Endotoxins / Q000008:administration & dosage / Q000235:genetics*; D004912:Erythrocytes / Q000187:drug effects; D006460:Hemolysin Proteins / Q000008:administration & dosage / Q000235:genetics*; D006801:Humans; D008214:Lymphocytes / Q000187:drug effects; D050505:Mutant Proteins / Q000008:administration & dosage / Q000235:genetics*; D010572:Pest Control, Biological; D030821:Plants, Genetically Modified / Q000235:genetics*
chemical_list: D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D004731:Endotoxins; D006460:Hemolysin Proteins; D050505:Mutant Proteins; C030956:insecticidal crystal protein, Bacillus Thuringiensis