title: ACTIVATION OF BACTERIAL ENDOSPORES.
abstract: A. Keynan (Israel Institute of Biological Research, Ness Ziona, Israel), Z. Evenchik, H. O. Halvorson, and J. W. Hastings. Studies on the activation of bacterial endospores. J. Bacteriol. 88:313-318. 1964.-Heat activation of bacterial endospores was imitated by suspending spores in reducing agents (mercaptoethanol or thioglycolate) or in a pH less than 4.5. Urea (6 m) had no effect on spores. In addition to the well-known activation at 65 C for 45 min, spores were also activated by exposure to 34 C for 48 hr. The activation by heat and by reducing agents was reversible; the reverse reaction was temperature-dependent. No reversion occurred at -20 C, whereas at 28 C the spores reversed to their original dormant state within 72 hr. It is suggested that the heat-activation phenomenon could be explained by assuming that heat or reducing agents change the tertiary structure of a protein responsible for the maintenance of the dormant state by reducing the disulfide linkages which stabilize the protein in a specific configuration. The partial denaturation of this protein is reversible by reoxidation of the reduced disulfide bonds.
mesh_terms: D000136:Acid-Base Equilibrium; D001409:Bacillus cereus; D001426:Bacterial Proteins; D003080:Cold Temperature; D006358:Hot Temperature; D007557:Israel; D010084:Oxidation-Reduction; D012106:Research; D013170:Spores; D013171:Spores, Bacterial
chemical_list: D001426:Bacterial Proteins
keywords: ACID-BASE EQUILIBRIUM; BACILLUS CEREUS; BACTERIAL PROTEINS; COLD; EXPERIMENTAL LAB STUDY; HEAT; OXIDATION-REDUCTION; SPORES