Variation of the Spore Population of a Natural Source Strain of Bacillus cereus in the Presence of Inosine

2004 ◽  
Vol 67 (5) ◽  
pp. 934-938 ◽  
Author(s):  
J. COLLADO ◽  
A. FERNÁNDEZ ◽  
M. RODRIGO ◽  
A. MARTÍNEZ
Keyword(s):  
Heat Resistance ◽  
Bacillus Cereus ◽  
Wild Strain ◽  
Natural Source ◽  
Spore Concentration ◽  
Factors Affecting ◽  
Germination Process ◽  
Germination Temperature ◽  
Spore Population ◽  
Spore Culture

The heat resistance of a wild strain of Bacillus cereus spores isolated from liquid egg was characterized, and the effect of the nutritional germinant inosine on the spore population was then studied, considering different factors such as germination temperature, inosine concentration, and age of spore culture. The heat resistance clearly indicates that these spores can survive mild heat treatments such as those used for cooked refrigerated food of extended durability or liquid egg, posing safety problems for these foods with temperature abuse. The germination study indicates that temperature, spore age, and the interaction between the two were the factors affecting the level of spores remaining after the germination process. No significant differences were found for the three inosine concentrations used in the study (1, 5, and 10 mM). The highest reduction in the spore concentration was reached at 30° C after 120 min, although the reduction in the spore counts at germination temperatures of 4 and 8° C was also considerable.

Death rates of bacterial spores: nonlinear survivor curves

1975 ◽  
Vol 21 (10) ◽  
pp. 1464-1467 ◽  
Author(s):  
Youn W. Han
Keyword(s):  
Heat Resistance ◽  
Bacillus Cereus ◽  
Saline Solution ◽  
Physiological Saline ◽  
Bacterial Spores ◽  
Death Rates ◽  
Physiological Saline Solution ◽  
Spore Population

Nonlinear survivor curves were obtained when spores of Bacillus cereus were heated in physiological saline solution. Curvilinear survivor curves did not appear to be caused by experimental artifacts but by the heterogeneity of spore population with regard to heat resistance.

Role of spore coats in the germinative response of Bacillus cereus to adenosine and its analogues

1992 ◽  
Vol 38 (1) ◽  
pp. 38-44 ◽  
Author(s):  
Sonia Senesi ◽  
Giulia Freer ◽  
Giovanna Batoni ◽  
Simona Barnini ◽  
Anna Capaccioli ◽  
...  
Keyword(s):  
Heat Resistance ◽  
Bacillus Cereus ◽  
Dipicolinic Acid ◽  
Germination Rate ◽  
Sodium Dodecyl ◽  
Rapid Evolution ◽  
Key Words Adenosine ◽  
Germination Process ◽  
Specific Activities

Spores of the strain NCIB 8122 of Bacillus cereus have been depleted of coats by treatment with 0.1% sodium dodecyl sulfate – 200 mM 2-mercaptoethanol – 0.5 M NaCl (pH 9.6). The coat-depleted spores did not show any decrease in viability, heat resistance, refractility, dipicolinic acid content, or specific activities of several protoplastic enzymes. The germinative response of the coat-depleted spores to adenosine and several analogues thereof was found qualitatively similar to that obtained with intact spores. However, germination kinetics appeared to be affected by coat removal, since germination rate measured as loss of refractility was eight times slower even at inducer concentrations 10-fold higher than those required to promote optimal germination response of intact spores. Loss of heat resistance, on the other hand, was hardly affected by coat removal. These results suggest that, even though spore coats are not essential for the triggering reaction, they are required for a rapid evolution of the later events in the germination process. Key words: adenosine analogues, germination-triggering reaction, spore coats, coat-depleted spores, Bacillus cereus.

scholarly journals Factors Contributing to Heat Resistance of Clostridium perfringens Endospores

2008 ◽  
Vol 74 (11) ◽  
pp. 3328-3335 ◽  
Author(s):  
Benjamin Orsburn ◽  
Stephen B. Melville ◽  
David L. Popham
Keyword(s):  
Cell Wall ◽  
Heat Resistance ◽  
Clostridium Perfringens ◽  
Food Poisoning ◽  
High Heat ◽  
Relative Importance ◽  
High Heat Resistance ◽  
Factors Affecting ◽  
Cooking Process ◽  
Determining Factors

ABSTRACT The endospores formed by strains of type A Clostridium perfringens that produce the C. perfringens enterotoxin (CPE) are known to be more resistant to heat and cold than strains that do not produce this toxin. The high heat resistance of these spores allows them to survive the cooking process, leading to a large number of food-poisoning cases each year. The relative importance of factors contributing to the establishment of heat resistance in this species is currently unknown. The present study examines the spores formed by both CPE+ and CPE− strains for factors known to affect heat resistance in other species. We have found that the concentrations of DPA and metal ions, the size of the spore core, and the protoplast-to-sporoplast ratio are determining factors affecting heat resistance in these strains. While the overall thickness of the spore peptidoglycan was found to be consistent in all strains, the relative amounts of cortex and germ cell wall peptidoglycan also appear to play a role in the heat resistance of these strains.

scholarly journals Sprouted Grains: A Comprehensive Review

Nutrients ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 421 ◽  
Author(s):  
Paolo Benincasa ◽  
Beatrice Falcinelli ◽  
Stanley Lutts ◽  
Fabio Stagnari ◽  
Angelica Galieni
Keyword(s):  
Scientific Literature ◽  
In Vivo Studies ◽  
Human Diet ◽  
Factors Affecting ◽  
Germination Process ◽  
Parallel Increase ◽  
Main Factors ◽  
Physiological And Biochemical ◽  
Phytochemical Contents

In the last decade, there has been an increase in the use of sprouted grains in human diet and a parallel increase in the scientific literature dealing with their nutritional traits and phytochemical contents. This review examines the physiological and biochemical changes during the germination process, and the effects on final sprout composition in terms of macro- and micro-nutrients and bioactive compounds. The main factors affecting sprout composition are taken into consideration: genotype, environmental conditions experimented by the mother plant, germination conditions. In particular, the review deepens the recent knowledge on the possible elicitation factors useful for increasing the phytochemical contents. Microbiological risks and post-harvest technologies are also evaluated, and a brief summary is given of some important in vivo studies matching with the use of grain sprouts in the diet. All the species belonging to Poaceae (Gramineae) family as well as pseudocereals species are included.

scholarly journals The survival and growth ofBacillus cereusin boiled and fried rice in relation to outbreaks of food poisoning

1974 ◽  
Vol 73 (3) ◽  
pp. 433-444 ◽  
Author(s):  
R. J. Gilbert ◽  
M. F. Stringer ◽  
T. C. Peace
Keyword(s):  
Heat Resistance ◽  
Bacillus Cereus ◽  
Storage Time ◽  
Aqueous Suspension ◽  
Food Poisoning ◽  
Optimum Temperature ◽  
Cooked Rice ◽  
Survival And Growth ◽  
And Storage

SummaryA number of outbreaks of food poisoning attributed toBacillus cereushave been reported recently and all have been associated with cooked rice usually from Chinese restaurants and ‘take-away’ shops.Tests were made to assess the heat resistance ofB. cereusspores in aqueous suspension, the growth of the organism in boiled rice stored at temperatures in the range 4–55° C., and the effect of cooking and storage on the growth of the organism in boiled and fried rice. The spores ofB. cereussurvived cooking and were capable of germination and outgrowth. The optimum temperature for growth in boiled rice was between 30° and 37° C. and growth also occurred during storage at 15° and 43° C.To prevent further outbreaks it is suggested that rice should be boiled in smaller quantities on several occasions during the day, thereby reducing the storage time before frying. After boiling the rice should either be kept hot (> 63° C.) or cooled quickly and transferred to a refrigerator within 2 hr. of cooking. Boiled or fried rice must not be stored under warm conditions especially in the range 15–50° C.

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