Involvement of the spore coat in germination of Bacillus cereus T spores.
Bacillus cereus T spores were prepared on fortified nutrient agar, and the spore coat and outer membrane were extracted by 0.5% sodium dodecyl sulfate-100 mM dithiothreitol in 0.1 M sodium chloride (SDS-DTT) at pH 10.5 (coat-defective spores). Coat-defective spores in L-alanine plus adenosine germinated slowly and to a lesser extent than spores not treated with SDS-DTT, as determined by decrease in absorbance and release of dipicolinic acid and Ca2+. Spores germinated in calcium dipicolinate only after treatment with SDS-DTT. Biphasic and triphasic germination kinetics were observed with normal and coat-defective spores, respectively, in an environment with temperature increasing from 20 to 65 degrees C at a rate of 1 degree C/min. Therefore, the physical and biochemical processes involved in germination are modified by coat removal. The data suggest that a portion of the germination apparatus located interior to the coat may be protected by the coat and outer membrane or that the coat and outer membrane otherwise enhance germination in L-alanine plus adenosine. When coat-defective spores were heat activated with the dialyzed (12,000-Mr cutoff) components extracted from the spores, germination of the SDS-DTT-treated spores was enhanced; thus, one or more components located in the spore coat or outer membrane with a molecular weight greater than 12,000 were essential for fast germination.
D000473:Alkanes / Q000378:metabolism; D001409:Bacillus cereus / Q000502:physiology* / Q000648:ultrastructure; D002118:Calcium / Q000378:metabolism; D002462:Cell Membrane / Q000502:physiology / Q000648:ultrastructure; D003470:Culture Media; D006358:Hot Temperature; D007700:Kinetics; D008854:Microscopy, Electron; D010848:Picolinic Acids / Q000378:metabolism; D013171:Spores, Bacterial / Q000502:physiology / Q000648:ultrastructure
D000473:Alkanes; D003470:Culture Media; D010848:Picolinic Acids; C007932:n-hexadecane; D002118:Calcium; C004860:dipicolinic acid