Studies on Dipicolinic Acid in the Spores of Bacillus Cereus Var. Terminalis

Harrell, William K.; Mantini, Emil L.

doi:10.1139/m57-082

Cited by 11 publications

(6 citation statements)

References 3 publications

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“…In contrast to other reports (8,12), in our strain of B. cereus T no loss of DPA from spores during activation in water was found. On the other hand, during low-pH activation, DPA was excreted and a continuous decrease in the DPA content of the spores could be noticed (Table 1).…”

Section: Resultscontrasting

confidence: 99%

Low- p H Activation of Bacillus cereus Spores

1970

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Heat activation of bacterial spores at low pH was investigated in detail. Unlike activation of spores in distilled water at a neutral pH, activation at low pH involves two superimposed processes: enhanced activation and death. Low-pH-activated spores failed to germinate in D-alanine, in contrast to spores activated at neutral pH, owing to the abolition of alanine-racemase activity. Morphological and permeability changes such as release and partial disruption of spores were dipicolinic acidobserved during low-pH activation. The kinetics pattern of low-pH activation, as well as the change in properties of the spores thereafter, suggest that the mechanism of low-pH activation differs from that of other kinds of heat-activation.

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Section: Resultscontrasting

confidence: 99%

Low- p H Activation of Bacillus cereus Spores

1970

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“…Activation of endospores is accompanied by an increase in the rate of endogenous metabolism, acquisition of the ability to oxidize glucose, excretion of dipicolinic acid (8), and an increase in the activity of intracellular proteases (4). Spores of S. viridochromogenes exhibit an increase in their endogenous metabolism rate and excrete small amounts of cell carbon after they have been activated (C. Hirsch, Ph.D thesis).…”

Section: Methodsmentioning

confidence: 99%

Heat activation of Streptomyces viridochromogenes spores

Hirsch¹,

Ensign²

1976

J Bacteriol

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The lag period preceding germination of Streptomyces viridochromogenes spores during incubation in a defined germination medium was completely eliminated by a gentle heat shock. The rate of germination was not affected. The optimum pH for activation extended from 6.0 to 9.6. The time of heating required for maximum activation was 1 min at 60 C, 2 to 5 min at 55 C, 20 min at 50 C, and 40 to 50 min at 45 C. Activated spores had the same temperature and pH optima and nutritional requirements for germination as unactivated spores. Activated spores deactivated during incubation for 8 h at 25 C and were activated again by a second heat shock. Spores that had been aged for 4 weeks or longer did not germinate in the defined germination medium unless they were first heat activated. CaCl2 2H2O and 0.01% MgSO,-7H,O (TX salts) is shown in Fig. 1, curve A. A slow, essentially linear decrease in OD was observed. This OD change was accompanied neither by loss of 24

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“…Since dipicolinic acid (pyridine-Z,6-dicarboxylic acid) is present in significant amounts in bacterial endospores (4,9) and is secreted during germination that Ca++ antagonizes to a large extent the inhibition by dipicolinic acid. Calcium itself has only a slight inhibitory effect on L-alanine induced germination (see belofi) and does not eliminate auto-inhibition, showing that the latter effect is not due to dipicolinic acid.…”

Section: Resultsmentioning

confidence: 99%

“…Since dipicolinic acid (pyridine-Z,6-dicarboxylic acid) is present in significant amounts in bacterial endospores (4,9) and is secreted during germination (4, 7) the effect of this compound on the inductive capacity of L-alanine was next examined. In the presence of 50 pM L-alanine and 10 pM glucose, 83% of the spore population (1 mg./tube) were germinated in 60 minutes, at which time'the rate of germination had leveled off.…”

Section: Resultsmentioning

confidence: 99%

FURTHER STUDIES ON BACTERIAL ENDOSPORE GERMINATION RELATIVE TO AUTO‐INHIBITION^a

Stedman

Kravitz

Harding

et al. 1957

Journal of Food Science

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The induction of bacterial endospore germination in simple aqueous solution by a variety of metabolic substances, alone and in various combinations, is well known. Systems of this type have been used extensively to investigate biochemical changes during the transition from spore to vegetative cell ; details of current knowledge of this subject have been recently reviewed by Stedman (9). Since the publication of this review, a previously undescribed phenomenon termed "auto-inhibition" has been shown in this laboratory to occur during germination of the spores of Bacillzrs globigii (10).In brief, it was reported that spores initially germinating in L-alanine and glucose solutions secrete an inhibitory substance which interferes with the germination of the remaining spores in the population. The present communication describes further studies on the induced germination of B. globigii and the influence of auto-inhibition on the germination pattern. EXPERIMENTAL Bacillus globigii, Fort Detrick strain, was used throughout the work. The organism was grown on "G" agar ( 1 ) fortified with 1% casein hydrolysate (dry weight basis) for 4-5 days, at which time microscopic observation showed that sporulation was complete.The spores were harvested, washed using the procedure of Stewart and Halvorson (11) and stored as concentrates in the freezer (-25" C.) . Spore suspensions stored for more than 2 weeks were discarded to avoid "aging" effects (2).In the germination induction experiments, concentrates were thawed, diluted in 0.067 M phosphate buffer (pH 7.0) to a concentration of 1 mg. dry weighuml., and heatshocked a t 65" C. for 15 minutes. Each tube contained glucose and L-alanine as inducers, 1 mg. spores, phosphate buffer and other substances (see Results) in a total volume of 5.0 ml., as described in a previous report (10). In a few instances, 0.05 M acetate buffer was substituted for the phosphate buffer; both buffers give essentially the same patterns of germination with alanine and glucose, although acetate is slightly slower than phosphate. .Percentage germination was determined by the turbidirnetric method of Hachisuka et al.(3) and occasionally confirmed by standard procedures involving uptake of methylene blue and loss of heat resistance (9).I n some instances kinetic analyses were performed by measuring the percentage germination in the presence and absence of specific exogenous inhibitors using the above germination induction method and by evaluating the data using the double reciprocal plot * of Lineweaver and Burk (5). In all cases, the maximum rate of germination occurred in the 1&20 minute interval after addition of inducers and inhibitors. Arbitrarily, the a The views expressed herein are those of the authors and are not necessarily similar to the views of the U. S. Department of the Navy. b* ' Present address :

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Studies on Dipicolinic Acid in the Spores of Bacillus Cereus Var. Terminalis

Cited by 11 publications

References 3 publications

Low- p H Activation of Bacillus cereus Spores

Low- p H Activation of Bacillus cereus Spores

Heat activation of Streptomyces viridochromogenes spores

FURTHER STUDIES ON BACTERIAL ENDOSPORE GERMINATION RELATIVE TO AUTO‐INHIBITION^a

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Studies on Dipicolinic Acid in the Spores of Bacillus Cereus Var. Terminalis

Cited by 11 publications

References 3 publications

Low- p H Activation of Bacillus cereus Spores

Low- p H Activation of Bacillus cereus Spores

Heat activation of Streptomyces viridochromogenes spores

FURTHER STUDIES ON BACTERIAL ENDOSPORE GERMINATION RELATIVE TO AUTO‐INHIBITIONa

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FURTHER STUDIES ON BACTERIAL ENDOSPORE GERMINATION RELATIVE TO AUTO‐INHIBITION^a