Single-spore elemental analyses indicate that dipicolinic acid-deficient Bacillus subtilis spores fail to accumulate calcium.
Dipicolinic acid (pyridine-2,6-carboxylic acid; DPA) is a major component of bacterial spores and has been shown to be an important determinant of spore resistance. In the core of dormant Bacillus subtilis spores, DPA is associated with divalent calcium in a 1:1 chelate (Ca-DPA). Spores excrete Ca-DPA during germination, but it is unknown whether Ca and DPA are imported separately or together into the developing spore. Elemental analysis by scanning electron microscopy-energy-dispersive X-ray spectroscopy (SEM-EDS) of wild-type spores and mutant spores lacking the ability to synthesize DPA showed that DPA-less spores also lacked calcium, suggesting that the two compounds may be co-imported.
Hintze
Paul E
PE
NASA Corrosion Technology Laboratory, Kennedy Space Center, Gainesville, FL 32899, USA.
Nicholson
Wayne L
WL
D001412:Bacillus subtilis / Q000737:chemistry* / Q000378:metabolism / Q000648:ultrastructure; D002118:Calcium / Q000032:analysis* / Q000378:metabolism; D008855:Microscopy, Electron, Scanning; D010848:Picolinic Acids / Q000032:analysis* / Q000378:metabolism; D013052:Spectrometry, X-Ray Emission; D013171:Spores, Bacterial / Q000737:chemistry / Q000648:ultrastructure; D013696:Temperature
D010848:Picolinic Acids; D002118:Calcium; C004860:dipicolinic acid