title: Fate of insecticidal Bacillus thuringiensis Cry protein in soil: differences between purified toxin and biopesticide formulation.
abstract: BACKGROUND
  Bacillus thuringiensis produces insecticidal proteins known as Cry, and its efficiency and absence of side effects make it the most widely used biopesticide. There is little information on the role of soils in the fate of Cry proteins from commercial biopesticide formulations, unlike toxins from genetically modified crops, which have been intensively studied in recent years. The persistence of Cry in soil was followed under field and laboratory conditions.
  
  
  RESULTS
  Sunlight accelerated loss of detectable Cry under laboratory conditions, but little effect of shade was observed under field conditions. The half-life of biopesticide proteins in soil under natural conditions was about 1 week. Strong temperature effects were observed, but they differed for biopesticide and purified protein, indicating different limiting steps.
  
  
  CONCLUSIONS
  For the biopesticide, the observed decline in detectable protein was due to biological factors, possibly including the germination of B. thuringiensis spores, and was favoured by higher temperature. In contrast, for purified proteins, the decline in detectable protein was slower at low temperature, probably because the conformational changes of the soil-adsorbed protein, which cause fixation and hence reduced extraction efficiency, are temperature dependent. © 2016 Society of Chemical Industry.
authors.affiliation: INRA, UMR Eco & Sols, INRA-IRD-Cirad-SupAgro, Montpellier, France.|Institute of Biotechnology, Vietnam Academy of Science and Technology, Hanoi, Vietnam.
authors.forename: Truong Phuc
authors.initials: TP
authors.lastname: Hung
authors.affiliation: INRA, UMR Eco & Sols, INRA-IRD-Cirad-SupAgro, Montpellier, France.|Institute of Biotechnology, Vietnam Academy of Science and Technology, Hanoi, Vietnam.
authors.forename: Le Van
authors.initials: LV
authors.lastname: Truong
authors.affiliation: Institute of Biotechnology, Vietnam Academy of Science and Technology, Hanoi, Vietnam.
authors.forename: Ngo Dinh
authors.initials: ND
authors.lastname: Binh
authors.affiliation: Université de Montpellier, UMR 5236, CPBS, CNRS-Université de Montpellier, Montpellier, France.|Cirad, UMR17, Intertryp, Cirad-IRD, TA-A17/G, Montpellier, France.
authors.forename: Roger
authors.initials: R
authors.lastname: Frutos
authors.affiliation: INRA, UMR Eco & Sols, INRA-IRD-Cirad-SupAgro, Montpellier, France.
authors.forename: Hervé
authors.initials: H
authors.lastname: Quiquampoix
authors.affiliation: INRA, UMR Eco & Sols, INRA-IRD-Cirad-SupAgro, Montpellier, France. staunton@montpellier.inra.fr.
authors.forename: Siobhán
authors.initials: S
authors.lastname: Staunton
mesh_terms: D001426:Bacterial Proteins / Q000302:isolation & purification / Q000378:metabolism; D006207:Half-Life; D019476:Insect Proteins; D007306:Insecticides / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000302:isolation & purification / Q000378:metabolism; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000378:metabolism; D013472:Sunlight; D014744:Vietnam
chemical_list: D001426:Bacterial Proteins; C095416:Cry toxin receptors; D019476:Insect Proteins; D007306:Insecticides; D011956:Receptors, Cell Surface; D012987:Soil; D012989:Soil Pollutants
keywords: Bacillus thuringiensis; Cry toxins; Cry1Ac; biopesticide; persistence in soil; soil