title: Radiation sensitivity of Bacillus cereus with and without a crystalline surface protein layer.
abstract: The radiation sensitivity of four strains of Bacillus cereus was investigated with attention to bacterial surface structure. All four strains were sensitive to radiation with gamma rays (D(10)=0.4 kGy). No crystalline surface protein layer could be detected on the cell surface. When cultured on solid media, an S-layer covered the cells of the two strains, and they were 2.6 times as resistant to radiation as the two reference strains without an S-layer. In SDS-PAGE, a major 97-kDa band from the resistant strains from plate cultures was replaced by a ca. 85-kDa protein band in samples from broth cultures. Electron microscopy, SDS-PAGE, Western blot and fluorescent antibody staining indicated that the higher resistance to radiation of the clinical strains from plate cultures was associated with the presence of the S-layer on the cell surface.
authors.affiliation: Institute of Dentistry, P.O. Box 41, University of Helsinki, FIN-00014, Helsinki, Finland. anja.kotiranta@helsinki.fi
authors.forename: A K
authors.initials: AK
authors.lastname: Kotiranta
authors.forename: H
authors.initials: H
authors.lastname: Ito
authors.forename: M P
authors.initials: MP
authors.lastname: Haapasalo
authors.forename: K
authors.initials: K
authors.lastname: Lounatmaa
mesh_terms: D001409:Bacillus cereus / Q000737:chemistry / Q000528:radiation effects*; D001426:Bacterial Proteins / Q000032:analysis / Q000528:radiation effects*; D005720:Gamma Rays; D008970:Molecular Weight; D011836:Radiation Tolerance
chemical_list: D001426:Bacterial Proteins