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Collapse of Cortex Expansion during Germination of Bacillus megaterium Spores
Author(s) -
Nakatani Yoshihiro,
Tanida Ikuko,
Koshikawa Tomihiko,
Imagawa Masayoshi,
Nishihara Tsutomu,
Kondo Masaomi
Publication year - 1985
Publication title -
microbiology and immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.664
H-Index - 70
eISSN - 1348-0421
pISSN - 0385-5600
DOI - 10.1111/j.1348-0421.1985.tb00873.x
Subject(s) - dipicolinic acid , bacillus megaterium , germination , spore , incubation , biology , divalent , calcium , biochemistry , cortex (anatomy) , hydrolysis , spore germination , microbiology and biotechnology , bacteria , botany , chemistry , genetics , organic chemistry , neuroscience
When spores of Bacillus megaterium ATCC 12872 were incubated with CdCl 2 , they germinated without decomposition of the cortex. Moreover, the volume ratio of cortex to protoplast‐plus‐cortex, C/(P + C), of the CdCl 2 ‐germinated spores was reduced. Incubation of isolated cortex with the divalent compounds Cd 2+ , Ca 2+ , and Mg 2+ reduced the gel volume to about 1/5 but incubation with a nonionic compounds, glucose, did not. The spores with reduced C/(P+C) were observed in the early period of glucose‐induced germination. The time required for a 50% change in cortex morphology to occur was 2.5 min, which corresponds well with the time for 50% loss of heat resistance. This time was shorter than that necessary for release of peptidoglycan fragments and hydrolysis of cortex glycan chains. These data indicate that cortex hydrolysis is not related to the initiation of germination. 50% of the dipicolinic acid, calcium and magnesium were released at 3.4, 4.0, and 2.4 min, respectively. These results suggest that collapse of cortex expansion by the interaction of cortex with dipicolinic acid and cations released from the core, or exogenous ionic germinants is an important step in the initiation of germination.