The Problem of “Dormancy” in Bacterial Spores

Foster, J. W.; Wynne, E. Staten

doi:10.1128/jb.55.5.623-625.1948

Cited by 17 publications

(9 citation statements)

References 6 publications

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“…It is possible that a peroxide effect may be involved in the phenomenon of dormancy shown by bacterial spores. Foster and Wynne (1948b) reported that oleic, linoleic, and linolenic acids inhibited germination in a manner similar to the dormancy phenomenon. Halvorson (1950) postulated that this might be due to the presence of peroxides rather than the unsaturated fatty acids themselves.…”

Section: Resultsmentioning

confidence: 92%

The Effect of Oxidative Rancidity in Unsaturated Fatty Acids on the Germination of Bacterial Spores

Roth

Halvorson

1952

J Bacteriol

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It has been reported that some lots of commercial media contain substances that inhibit germination of anaerobic spores which can be overcome by adding starch (Foster and Wynne, 1948a). Foster and Wynne ascribed this activity to the unsaturated C18 fatty acids. Halvorson (1950) suggested that this effect may be due to the formation of peroxides from the fatty acids. This investigation was undertaken to test the latter hypothesis. MATERIALS AND METHODS Organisms used. The routine test organism was a putrefactive anaerobe, strain P.A. 3679. Later tests were also run on Clostridium botulinum, strain 7948, Clostridium pasteurianum, strain 7040, Bacillus subtilis, strain of Upjohn Company, and Bacilus stearothermophilus, strain NCA 1518. Preparation of spore suspensions. Anaerobic spores were collected after inoculating Blake bottles containing Yesair's pork infusion agar (Wynne and Foster, 1948) with a suspension of cells containing both spores and vegetative cells. The inoculum for each bottle consisted of 1.5 ml of a 72 hour egg-meat culture (Difco). The bottles were incubated for one week at 37 C in a desiccator which had been evacuated and the air replaced with natural gas. Cells were harvested by washing off the agar surface with sterile distilled water.

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Section: Resultsmentioning

confidence: 92%

The Effect of Oxidative Rancidity in Unsaturated Fatty Acids on the Germination of Bacterial Spores

Roth

Halvorson

1952

J Bacteriol

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“…Superdormant spores havc been observed in heated products many times (see Hersom & Hulland, 1963), but it is important to realize that they probably exist in all spore populations whether or not they have been heat damaged. Foster & Wynne (1948) stated that the characteristic feature of classical dormancy is a slow increase in colony count or in 'positive tubes' (ix. in most probable number techniques).…”

Section: Discussionmentioning

confidence: 99%

Limitations of the Initiation of Germination of Bacterial Spores as a Spore Control Procedure

Gould

And

Wrighton

1968

Journal of Applied Bacteriology

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Germination of spores of Bacillus cougulans, B. cereus and mixed soil spores in nonnutritive buffer, in rich laboratory media and in foods was accelerated, and the final amount of germination was increased, when germinants were added (e.g. L-alanine, L-or-aminobutyric acid, inosine, combinations of L-alanine with ribosides like guanosine and adenosine). Further potentiation of the rate and amount of L-alanine-initiated germination was caused by adding the inhibitor of alanine racemase, o-carbamyl-D-serine. The germination rate always decreased markedly after about the first 10or 100-fold fall in level of surviving ungerminated spores, in keeping with the concept that populations of bacterial spores are heterogeneous as regards germinability of the individual spores. Although the presence of the germinants and potentiators of germination lowered the levels of spores remaining ungerminated after incubation in various media and foods, a superdormant fraction of the spore populations always remained. The limitations imposed by superdormancy on the use of initiation of germination as a step in spore destruction processes are highlighted, and some difficulties in the study of superdormant spores are discussed.

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“…Burke (1923) thought dormancy was an inherent property of C. botulinum spores. Foster and Wynne (1948) concluded that both dormancy and submaximal counts are due to inhibitory or antigermination substances present in "normal media." The data presented here show that delayed germination and low counts in pork infusion medium are overcome by the addition of HCO-to the medium.…”

Section: Discussionmentioning

confidence: 99%

A Rapid Plate Method of Counting Spores of Clostridium Botulinum

Andersen

1951

J Bacteriol

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Making accurate counts of the spores of Clostridium botulinum has been a formidable problem in food bacteriology. A literature survey revealed no standard or widely accepted method. In general, long incubation times have been employed in an effort to count these spores, many of which may remain dormant for weeks or even years. The present paper describes a fast plate method for counting spores of C. botulinum. The method is based on the development of an adequate medium which includes HCO_ and the use of a new plating technique which produces anaerobiosis and permits the plate to be counted or examined at any time. METHOD Medium (VII). Pork infusion, 800 ml; pea infusion, 200 ml; peptone, 5 g; tryptone, 1.6 g; K2HPO4, 1.25 g; soluble starch, 1 g; Na thioglycolate, 0.5 g; N NaOH to pH 7.2; agar, 16 g. The materials are autoclaved 5 minutes at 121 C and clarified while hot by adding 25 g of "celite"2 and filtering through Whatman no. 42 filter paper with suction. The medium is tubed in 9 and 14 ml quantities and can be stored in a closed container in a freezer. As needed the tubes are autoclaved at 15 pounds for 12 minutes. The pork infusion is made as follows: fresh, lean pork is ground, stirred into hot distilled water (1 lb per L), and steamed 1 hour. The meat is filtered out on 4 layers of cheesecloth, and the solidified fat is removed after cooling. The pea infusion is made as follows: fresh or good-quality frozen peas are blended with distilled water (1:1) and steamed 1 hour. The solids are removed by centrifugation and filtration with celite. If not used immediately the pork or pea infusions can be stored at 0 F in enameled cans. The complete medium also contains NaHCO3 which gives best results if added to the dish at the time of pouring. A freshly prepared solution of 5 g of NaHCO3 per 100 ml is sterilized by pressure Seitz filtration and, if not used immediately, is kept in sterile screw-cap tubes in a refrigerator. Plating. The anaerobic petri dish used in this wvork is set up as shown in figure 1. To the petri dish (no. 3162, Corning Glass Works2) 0.4 ml of the NaHCO3 solution, 14 ml of the medium, and the inoculum are added and mixed. After

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The Problem of “Dormancy” in Bacterial Spores

Cited by 17 publications

References 6 publications

The Effect of Oxidative Rancidity in Unsaturated Fatty Acids on the Germination of Bacterial Spores

The Effect of Oxidative Rancidity in Unsaturated Fatty Acids on the Germination of Bacterial Spores

Limitations of the Initiation of Germination of Bacterial Spores as a Spore Control Procedure

A Rapid Plate Method of Counting Spores of Clostridium Botulinum

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