Killing of spores of Bacillus subtilis by peroxynitrite appears to be caused by membrane damage

• Published in: Microbiology (Society for General Microbiology) Vol. 148; no. 1; pp. 307 - 314
• Main Authors: Genest, Peter C, Setlow, Barbara, Melly, Elizabeth, Setlow, Peter
• Format: Journal Article
• Language: English
• Published: Reading Soc General Microbiol 01.01.2002; Society for General Microbiology
• Subjects: Action of physical and chemical agents on bacteria; Bacillus subtilis; Bacillus subtilis - drug effects; Bacillus subtilis - genetics; Bacillus subtilis - physiology; Bacteriology; Biological and medical sciences; Cell Membrane - drug effects; dipicolinic acid; Drug Resistance, Bacterial; Fundamental and applied biological sciences. Psychology; Microbiology; peroxynitrite; Peroxynitrous Acid - metabolism; Peroxynitrous Acid - pharmacology; Picolinic Acids - metabolism; Spores, Bacterial - drug effects; Spores, Bacterial - genetics; Spores, Bacterial - physiology; Bacillales; Bacillus subtilis; Mortality; Bacteria; Bacillaceae; Spores; Internal membrane
• ISSN: 1350-0872; 1465-2080
• DOI: 10.1099/00221287-148-1-307

Department of Biochemistry, University of Connecticut Health Center, Farmington, CT 06032, USA 1 Author for correspondence: Peter Setlow. Tel: +1 860 679 2607. Fax: +1 860 679 340. e-mail: setlow{at}sun.uchc.edu During an infection of a higher eukaryote, dormant spores of a Bacillus species have been previously shown to be present in cells that can generate the toxic agent peroxynitrite (PON). Dormant spores of Bacillus subtilis were much more resistant to killing by PON than were growing cells, and spore-coat alteration or removal greatly decreased PON resistance. Spores were not killed by PON through DNA damage and lost no dipicolinic acid (DPA) during PON treatment. However, PON-killed spores lost DPA during subsequent heat treatments that caused much less DPA release from untreated spores. Although dead, the PON-killed spores germinated and initiated metabolism but never went through outgrowth; the great majority of germinated PON-killed spores also took up propidium iodide, indicating that they had suffered significant membrane damage and were dead. Together these data suggest that spore killing by PON is through some type of damage to the spore’s inner membrane. Keywords: spore resistance, spore killing, membrane damage Abbreviations: DPA, dipicolinic acid; PON, peroxynitrite; SASP, small acid-soluble protein