1991 Fiscal Year Final Research Report Summary
Mechanism of heat resistance of bacterial spores
| Project/Area Number |
02670185
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
細菌学
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| Research Institution | Nagoya City University |
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Principal Investigator |
TOCHIKUBO Kunio Nagoya City University Medical School, Professor, 医学部, 教授 (30079991)
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| Co-Investigator(Kenkyū-buntansha) |
ICHIKAWA Yuko (藤田 祐子) Nagoya City University Medical School, Research Associate, 医学部, 助手 (80173441)
YASUDA Yoko Nagoya City University Medical School, Assistant Professor, 医学部, 講師 (70080009)
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| Project Period (FY) |
1990 – 1991
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| Keywords | Bacillus subtilis / Bacterial spore / Heat resistance / Hydrostatic pressure / Germination / Dipicolinic acid / Glucose dehydrogenase |
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| Research Abstract |
The following experiments were carried out for the purpose of clarification of the heat resistance of bacterial spores.
1. Death of bacterial spores by hydrostatic pressure at various temperatures.
The dormant spores of Bacillus subtilis treated at 4ﾟC for 1 h with hydrostatic pressures between 1, 000 and 5, 000 kg/cm^2 remained alive without being affected very much. On the other hand, a great majority of dormant spores treated at 37ﾟC and 60ﾟC under the same conditions of hydrostatic pressure were killed and the phenomena observed resembled those of physiological germination by L-alanine.
2. Purification of inactive glucose dehydrogenase from dormant spores.
Glucose dehydrogenase is considered to play an important role in energy production immediately after germination and we have estimated that the enzyme is present in dormant spores as an inactive form consisting of two subunits with M. W. of 30K and becomes an active form having four subunits during germination. Therefore, purification of the inactive form of the enzyme from B. subtilis spores has been tried using the antibodies raised against the 192-207 peptide and the active fore of the enzyme from Bacillus megaterium. The latter antibody appeared to be available. The binding of dipicolinic acid (DPA) to the purified inactive enzyme would be examined in connection with heat resistance of spores.
3. Detection and purification of DPA-binding macromoleculer substances in dormant spores.
Although DPA is contained abundantly in bacterial spores, its role remains unclear. Therefore, we have been trying to detect some DPA-binding macromolecular substances in dormant spores of B. subtilis using the antibody against DPA. Two substances with H. W. of 440K and 230K were detected and their purification is in progress. The role of DPA in heat resistance would be examined.
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