title: Maturation of released spores is necessary for acquisition of full spore heat resistance during Bacillus subtilis sporulation.
abstract: The first ∼10% of spores released from sporangia (early spores) during Bacillus subtilis sporulation were isolated, and their properties were compared to those of the total spores produced from the same culture. The early spores had significantly lower resistance to wet heat and hypochlorite than the total spores but identical resistance to dry heat and UV radiation. Early and total spores also had the same levels of core water, dipicolinic acid, and Ca and germinated similarly with several nutrient germinants. The wet heat resistance of the early spores could be increased to that of total spores if early spores were incubated in conditioned sporulation medium for ∼24 h at 37°C (maturation), and some hypochlorite resistance was also restored. The maturation of early spores took place in pH 8 buffer with Ca(2+) but was blocked by EDTA; maturation was also seen with early spores of strains lacking the CotE protein or the coat-associated transglutaminase, both of which are needed for normal coat structure. Nonetheless, it appears to be most likely that it is changes in coat structure that are responsible for the increased resistance to wet heat and hypochlorite upon early spore maturation.
authors.affiliation: Department of Molecular, Microbial and Structural Biology, University of Connecticut Health Center, Farmington, CT 06030-3305, USA.
authors.forename: Jose-Luis
authors.initials: JL
authors.lastname: Sanchez-Salas
authors.forename: Barbara
authors.initials: B
authors.lastname: Setlow
authors.forename: Pengfei
authors.initials: P
authors.lastname: Zhang
authors.forename: Yong-Qing
authors.initials: YQ
authors.lastname: Li
authors.forename: Peter
authors.initials: P
authors.lastname: Setlow
mesh_terms: D001412:Bacillus subtilis / Q000737:chemistry / Q000187:drug effects / Q000502:physiology* / Q000528:radiation effects; D002118:Calcium / Q000032:analysis; D006358:Hot Temperature; D006997:Hypochlorous Acid / Q000633:toxicity; D050296:Microbial Viability / Q000528:radiation effects*; D010848:Picolinic Acids / Q000032:analysis; D013171:Spores, Bacterial / Q000737:chemistry / Q000187:drug effects / Q000502:physiology* / Q000528:radiation effects; D013312:Stress, Physiological; D014466:Ultraviolet Rays; D014867:Water / Q000032:analysis
chemical_list: D010848:Picolinic Acids; D014867:Water; D006997:Hypochlorous Acid; D002118:Calcium; C004860:dipicolinic acid