Photoprotection of Bacillus thuringiensis kurstaki from ultraviolet irradiation
- Department of Entomology, Faculty of Agriculture, Hebrew University of Jerusalem, Rehovot (Israel)
Irradiation of Bacillus thuringiensis var. kurstaki HD1 at 300-350 nm for up to 12 hr using a photochemical reactor results in a rapid loss of its toxicity to larvae of Heliothis armigera. Photoprotection of the toxic component was obtained by adsorption of cationic chromophores such as acriflavin (AF), methyl green, and rhodamine B to B. thuringiensis. AF gave the best photoprotection and a level of 0.42 mmol/g dye absorbed per gram of B. thuringiensis was highly toxic even after 12 hr of ultraviolet (uv) irradiation as compared to the control (77.5 and 5% of insect mortality, respectively). Ultraviolet and Fourier-transform infrared spectroscopic studies indicate molecular interactions between B. thuringiensis and AF. The nature of these interactions and energy or charge transfer as possible mechanisms of photoprotection are discussed. It is speculated that tryptophan residues are essential for the toxic effect of B. thuringiensis. It is suggested that photoprotection is attained as energy is transferred from the excited tryptophan moieties to the chromophore molecules.
- OSTI ID:
- 5459641
- Journal Information:
- Journal of Invertebrate Pathology; (United States), Vol. 57:3; ISSN 0022-2011
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ACRIFLAVINE
RADIOSENSITIVITY EFFECTS
BACILLUS
BIOLOGICAL RADIATION EFFECTS
DYES
INSECTS
BACTERIAL DISEASES
ENERGY TRANSFER
FOURIER TRANSFORMATION
INFECTIVITY
PHOTOCHEMISTRY
RHODAMINES
ULTRAVIOLET RADIATION
ULTRAVIOLET SPECTRA
ACRIDINES
AMINES
ANIMALS
AROMATICS
ARTHROPODS
AZAARENES
AZINES
BACTERIA
BIOLOGICAL EFFECTS
CARBOXYLIC ACIDS
CHEMISTRY
DISEASES
ELECTROMAGNETIC RADIATION
FLAVINES
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
INFECTIOUS DISEASES
INTEGRAL TRANSFORMATIONS
INVERTEBRATES
MICROORGANISMS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
PYRIDINES
RADIATION EFFECTS
RADIATIONS
REAGENTS
SPECTRA
TRANSFORMATIONS
560130* - Radiation Effects on Microorganisms