The Heat Resistance of Bacterial Spores

Williams, O. B.

doi:10.1093/infdis/44.6.421

Cited by 73 publications

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“…Alderton et al (1964) have shown that spores devoid of exchangeable calcium (H-form), would give a concave upward survival curve when heated in a medium rich in calcium, and that, in such conditions, they could regain the heat resistance of the native spores. Other authors (Williams 1929;Busta 1967;Han 1975) have referred to a modification of resistance of spores during the treatment. According to Prokop & Humphrey (1970), this modification 'could be thought of as mutation occurring during the process'.…”

Section: B Interpretation Of the Tailing Phenomenon (I) Tailing Is Amentioning

confidence: 99%

A REVIEW Tailing of Survival Curves of Bacterial Spores

Cerf

1977

Journal of Applied Bacteriology

493

279

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Section: B Interpretation Of the Tailing Phenomenon (I) Tailing Is Amentioning

confidence: 99%

A REVIEW Tailing of Survival Curves of Bacterial Spores

Cerf

1977

Journal of Applied Bacteriology

493

279

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“…The tubes were immersed in the oil bath for the specified time, and then the basket and tubes were removed from the oil bath and cooled in ice water. The tubes were freed of oil, flamed, and opened by means of a device similar to that described by Williams (6). The tubes were subcultured in dextrose broth (pH 6.5).…”

mentioning

confidence: 99%

EFFECT OF ALLYLISOTHIOCYANATE AND RELATED SUBSTANCES ON THE THERMAL RESISTANCE OF ASPERGILLUS NIGER, SACCHAROMYCES ELLIPSOIDEUS, AND BACILLUS THERMO ACIDURANS^a

Eosker

Esselen

Fellers

1951

Journal of Food Science

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I n a previous report we reviewed the use of mustard seed and allylisothiocyanate (mustard oil) as preservatives for fruit juices ( 3 ) , and preliminary data on the preservation of fresh cider and grape juice by these substances was reported, It was indicated that allylisothiocyanate in concentrations of approximately 20 p. p. m., exerted a favorable preservative action on fresh cider.The present investigation was carried out to ascertain the effect of allylisothiocyanate, oil of garlic, and oil of onion on the thermal resistance of Aspe+gillus niger, Xaccharomyces ellipsoideus, and Bacillus themnoacidurans. These organisms were examples of spoilage microorganisms that might be encountered in acid foods. EXPERIMENTAL PROCEDURE MicroorganismsThe representative test organisms selected were Aspergillus niger and Saccharomycea ellipsoideus, taken from stock cultures in this laboratory, and Bacillus thermoaciclurans, strain number 8038 (Bacillus coagulam) from the American Type Culture Collection. SubstratesCitric acid-dibasic sodium phosphate buffer solutions for pH 4.0 and 7.0 were prepared according t o McIlvaine ( 4 ) . Freshly pressed apple juice was filtered and held in the frozen state in glass containers prior to use. The juice employed had a pH value of 3.9 and a soluble solids content of 13.8%. Pasteurized Concord. grape juice was prepared in the laboratory. It had a pH value of 3.8 and a soluble solids content of 16.5%. A given lot of washed, trimmed tomatoes cut into quarters, were placed in a steamjacketed kettle and heated t o boiling. Then the hot pulp was passed through a cyclone finisher and the juice was then filled at 87.7"C.(190°F.) into No. 10 (603 x 700) unlined cans which were processed in boiling water. Preparation of Spore and Yeast Cell SuspensionsThe Aspergillus niger spore crops were grown on slants of dextrose agar (Difco) and apple juice agar (prepared by adding 2% ag&r to apple juice) for 12 days at room temperature [21a to 24"C.(70° to 75"F.)]. The spores were washed from the agar slants with sterile physiological saline and collected in a sterile flask. The spore 811s-pension was then filtered through a sterile cheese cloth cotton filter pad and the filtrate placed in 50-ml. centrifuge tubes and centrifuged for 15 minutes a t 3,000 r.p.m. to concentrate the spores. The spores were washed from the centrifuge tube with 5 ml. of saline and placed in a sterile flask containing glass beads. The spore concentration was Contribution No. 808, Massachusetts Agricultural Experiment Station. Present address,

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“…The effect of storage conditions on the retention of the original heat resistance of spores (not the change to the heat-labile state as studied by Bullock & Tallentire (1952)) is not clear. Drying and then storage in the dry state or in liquid media have been reported either to increase or to decrease the heat resistance of the spores (Magoon, 1926;Williams, 1929). Magoon (1926) stored thin layers of sporulated cultures of Bacillus mycoides for up to 180 days at 0, 0.50 and 1.00 a, at 10, 20 and 30".…”

Section: Introductionmentioning

confidence: 99%

The Effect of Water Activity, Solutes and Temperature on the Viability and Heat Resistance of Freeze-dried Bacterial Spores

Marshall

Murrell

Scott

1963

Journal of General Microbiology

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SUMMARYFreeze-dried spores of Bacillus megaterium, B. stearotkmphilus, Clostridium bifermentaw and C . botulinum type E suffered little or no loss in viability after storage a t 25" at water activity (a,) values between 0-2 and 0.8. When stored over P,O, (0.00 a,) the spores of all four species showed a marked loss in viability. The above results were similar for spores whether stored in air or in vacuum. With spores stored over distilled water (1.00 a,) the Bacillus spores underwent a large loss of viability in vacuum, but not in air; for spores of the clostridia the reverse was true. The addition of DL-glyceraldehyde, diacetyl or ribose (0.05 M) to the spore suspensions before drying caused increased death during storage at 0.50 aw and to a lesser extent a t 0.20 a,. Death was greater at 30' than at 10". The addition of sucrose, glutamate or semi-carbazide did not decrease the viability. When the dried spores were resuspended in dilute phosphate buffer after storage for 2-6 years their resistance to heating was greatest after storage at a, values of 04, 0.6 and 0.8.

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The Heat Resistance of Bacterial Spores

Cited by 73 publications

References 0 publications

A REVIEW Tailing of Survival Curves of Bacterial Spores

A REVIEW Tailing of Survival Curves of Bacterial Spores

EFFECT OF ALLYLISOTHIOCYANATE AND RELATED SUBSTANCES ON THE THERMAL RESISTANCE OF ASPERGILLUS NIGER, SACCHAROMYCES ELLIPSOIDEUS, AND BACILLUS THERMO ACIDURANS^a

The Effect of Water Activity, Solutes and Temperature on the Viability and Heat Resistance of Freeze-dried Bacterial Spores

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The Heat Resistance of Bacterial Spores

Cited by 73 publications

References 0 publications

A REVIEW Tailing of Survival Curves of Bacterial Spores

A REVIEW Tailing of Survival Curves of Bacterial Spores

EFFECT OF ALLYLISOTHIOCYANATE AND RELATED SUBSTANCES ON THE THERMAL RESISTANCE OF ASPERGILLUS NIGER, SACCHAROMYCES ELLIPSOIDEUS, AND BACILLUS THERMO ACIDURANSa

The Effect of Water Activity, Solutes and Temperature on the Viability and Heat Resistance of Freeze-dried Bacterial Spores

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About

EFFECT OF ALLYLISOTHIOCYANATE AND RELATED SUBSTANCES ON THE THERMAL RESISTANCE OF ASPERGILLUS NIGER, SACCHAROMYCES ELLIPSOIDEUS, AND BACILLUS THERMO ACIDURANS^a