SOME CHARACTERISTICS OF SPORES OF BACILLUS CEREUS PRODUCED BY A REPLACEMENT TECHNIQUE

1963 ◽  
Vol 9 (2) ◽  
pp. 251-258 ◽  
Author(s):  
Elisabeth Ann Pelcher ◽  
H. P. Fleming ◽  
Z. John Ordal
Keyword(s):  
Heat Resistance ◽  
Bacillus Cereus ◽  
Dipicolinic Acid ◽  
Fresh Medium ◽  
Distilled Water ◽  
Normal Complement ◽  
Strontium Barium ◽  
Replacement Technique ◽  
Low Levels ◽  
The Relationship

A replacement technique, whereby spores of Bacillus cereus were produced by transferring vegetative cells into non-nutritive solutions, was employed for the investigation of the relationship between calcium, dipicolinic acid (DPA), and heat resistance in spores. Replacement solutions of distilled water, fresh medium, calcium, strontium, barium, nickel, and other metals were employed. Spores produced in distilled water were heat sensitive and contained low levels of calcium and DPA. Heat-resistant spores with a normal complement of calcium and DPA were formed only in fresh medium or in solutions containing suitable levels of calcium. Calcium and DPA were present in the spores in nearly equimolar quantities. Of the other metals tested, only strontium stimulated DPA synthesis above the level of the spores produced in water. Spores of intermediary heat resistance but low DPA content were formed in solutions of barium and nickel.

Mutants of Bacillus cereus strain T that produce thermoresistant spores lacking dipicolinate and have low levels of calcium

1972 ◽  
Vol 18 (7) ◽  
pp. 1139-1143 ◽  
Author(s):  
R. S. Hanson ◽  
M. V. Curry ◽  
J. V. Garner ◽  
H. Orin Halvorson
Keyword(s):  
Bacillus Cereus ◽  
Liquid Medium ◽  
Dipicolinic Acid ◽  
Distilled Water ◽  
Bacterial Endospores ◽  
Low Levels

Mutants of Bacillus cereus strain T that produce thermoresistant spores which lack dipicolinic acid and have low levels of calcium and manganese have been isolated. The thermoresistant dipicolinate-less spores lose thermoresistance upon storage in distilled water and do not germinate in any liquid medium tested. All spores germinated and produced colonies on G medium agar. It is suggested that calcium and dipicolinic acid are not required for the acquisition of thermoresistance in bacterial endospores but that they are essential to the maintenance of the thermorésistant state and are required for normal germination.

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.

STUDIES OF ASPOROGENIC MUTANTS OF BACILLUS CEREUS: PRELIMINARY INVESTIGATIONS WITH CALCIUM AND ZINC

1962 ◽  
Vol 8 (6) ◽  
pp. 823-833 ◽  
Author(s):  
J. J. Cooney ◽  
D. G. Lundgren
Keyword(s):  
Heat Resistance ◽  
Bacillus Cereus ◽  
Trichloroacetic Acid ◽  
Minimal Medium ◽  
Soluble Fraction ◽  
Dipicolinic Acid ◽  
Insoluble Fraction ◽  
Temperature Sensitive ◽  
Vegetative Cells ◽  
Culture Cycle

The physiology of spore formation was studied in Bacillus cereus and a temperature-sensitive asporogenic mutant. The parent organism sporulates when cultured in a minimal medium at either 28 °C or 37 °C while the mutant sporulates only at 28 °C. The blocking of sporulation at 37 °C has been referred to as "abortive" sporulation. Uptake of calcium and zinc was followed during growth and sporulation or "abortive" sporulation. Calcium and dipicolinic acid (DPA) levels in sporogenic cultures increased as the medium calcium was increased. The asporogenic mutant took up less calcium and synthesized little DPA. Heat resistance of spores increased as the calcium and DPA increased. Over 99% of Ca45or Zn65were released from labelled spores when autoclaved to release DPA. Chemical fractionations were made of cells labelled with Zn65and Ca45and harvested at different times during the culture cycle. Smaller percentages of calcium than of zinc were located in the cold trichloroacetic acid soluble fraction. The alcohol-soluble, ether-insoluble fraction of spores contained a greater percentage of calcium than was found in vegetative cells. Cells which had undergone "abortive" sporulation contained the same percentage of calcium in this fraction as homologous vegetative cells.

CALCIUM REVERSAL OF THE HEAT SUSCEPTIBILITY AND DIPICOLINATE DEFICIENCY OF SPORES FORMED "ENDOTROPHICALLY" IN WATER

1960 ◽  
Vol 6 (2) ◽  
pp. 213-224 ◽  
Author(s):  
Samuel H. Black ◽  
Tadayo Hashimoto ◽  
Philipp Gerhardt
Keyword(s):  
Gamma Radiation ◽  
Bacillus Cereus ◽  
Calcium Ions ◽  
Dipicolinic Acid ◽  
Distilled Water ◽  
Vegetative Cells ◽  
Low Concentration

Spores of Bacillus cereus strain terminalis formed "endotrophically" by transferring granular vegetative cells to distilled water were found to be relatively susceptible to heat and deficient in dipicolinic acid. Calcium ions alone, added in low concentration shortly after the cells were placed in water, could completely relieve these abnormalities. Although the water-formed spores were sensitive to heat, they were as fully resistant as normal spores to gamma radiation or phenol.

What Does Human Development Index Rating Mean in Terms of Individualism/Collectivism?

2003 ◽  
Vol 8 (2) ◽  
pp. 97-100 ◽  
Author(s):  
Maria José Sotelo ◽  
Luis Gimeno
Keyword(s):  
Human Development ◽  
Human Development Index ◽  
Principal Component ◽  
General Idea ◽  
Development Index ◽  
Low Levels ◽  
The Relationship

The authors explore an alternative way of analyzing the relationship between human development and individualism. The method is based on the first principal component of Hofstede's individualism index in the Human Development Index rating domain. Results suggest that the general idea that greater wealth brings more individualism is only true for countries with high levels of development, while for middle or low levels of development the inverse is true.

The Effect of Copper Ions on Clot Lysis Time in the Fibrinolytic Assay of Streptokinase

1965 ◽  
Vol 13 (02) ◽  
pp. 477-483
Author(s):  
Alwin B. Bogert
Keyword(s):  
Copper Ions ◽  
Borate Buffer ◽  
Fibrinolytic System ◽  
Clot Lysis ◽  
Distilled Water ◽  
Naturally Occurring ◽  
Lysis Time ◽  
Low Levels ◽  
Effect Of Copper ◽  
Clot Lysis Time

SummaryExperiments were conducted to determine why different lots of Borate Buffer reagent affect the clot lysis times obtained in the fibrinolytic assay of Streptokinase. Minerals naturally occurring in distilled water were screened individually to determine their influence on lysis. Copper was found to have a very pronounced effect in this regard on the fibrinolytic system in that low levels reduce the lysis time and high levels increase it.

Ups and downs on the roller coaster of task conflict: the role of group cognitive complexity, collective emotional intelligence and team creativity

2020 ◽  
Vol 18 (1) ◽  
pp. 23-37
Author(s):  
Andreea Gheorghe ◽  
Oana Fodor ◽  
Anișoara Pavelea
Keyword(s):  
Emotional Intelligence ◽  
Cognitive Complexity ◽  
Empirical Support ◽  
Task Conflict ◽  
Team Creativity ◽  
Mediating Role ◽  
Low Levels ◽  
Explanatory Mechanism ◽  
The Relationship

This study explores the association between task conflict and team creativity and the role of group cognitive complexity (GCC) as a potential explanatory mechanism in a sample of 159 students organized in 49 groups. Moreover, we analyzed the moderating effect of collective emotional intelligence (CEI)in the relationship between task conflict and GCC.As hypothesized, we found that task conflict has a nonlinear relationship with GCC, but contrary to our expectations, it follows a U-shaped association, not an inversed U-shape. In addition,the moderating role of CEI was significant only at low levels. Contrary to our expectation, the mediating role of GCC did not receive empirical support. Theoretical and practical contributions are discussed.

Illicit Economies and Political Violence in Central Asia

2020 ◽  
Author(s):  
Lawrence P. Markowitz ◽  
Mariya Y. Omelicheva
Keyword(s):  
Central Asia ◽  
Political Violence ◽  
Drug Trade ◽  
Weak States ◽  
Collaborative Relationships ◽  
Organized Violence ◽  
Muslim Majority ◽  
Low Levels ◽  
The Relationship ◽  
Terrorist Violence

This chapter examines low levels of terrorist violence in Muslim-majority societies. Studies of terrorism have tended to view the relationship between religion and violence through the narrow lens of security, thereby overpredicting the extent of terrorist violence across societies. After reviewing the various explanations for terrorist violence, and applying them to Central Asia, this chapter explores the conditions under which a state’s involvement in illicit economies—specifically its collusion in the drug trade—can dampen levels of terrorist violence. Combining quantitative analysis (including GIS-enabled tools) with a series of in-depth expert interviews conducted in Central Asia, it emphasizes the complex political economy of security that defines infrastructurally weak states, where political and security apparatuses are often immersed in informal and illicit economies. This approach helps uncover the complex links between religion and organized violence, where state apparatuses are often drawn into collaborative relationships with nonstate actors.

scholarly journals Molecular Physiological Characterization of a High Heat Resistant Spore Forming Bacillus subtilis Food Isolate

2021 ◽  
Vol 9 (3) ◽  
pp. 667
Author(s):  
Zhiwei Tu ◽  
Peter Setlow ◽  
Stanley Brul ◽  
Gertjan Kramer
Keyword(s):  
Bacillus Subtilis ◽  
Heat Resistance ◽  
Dipicolinic Acid ◽  
Laboratory Strain ◽  
High Heat ◽  
High Heat Resistance ◽  
Vegetative Cells ◽  
Heat Resistant ◽  
Food Isolate ◽  
Wet Heat

Bacterial endospores (spores) are among the most resistant living forms on earth. Spores of Bacillus subtilis A163 show extremely high resistance to wet heat compared to spores of laboratory strains. In this study, we found that spores of B. subtilis A163 were indeed very wet heat resistant and released dipicolinic acid (DPA) very slowly during heat treatment. We also determined the proteome of vegetative cells and spores of B. subtilis A163 and the differences in these proteomes from those of the laboratory strain PY79, spores of which are much less heat resistant. This proteomic characterization identified 2011 proteins in spores and 1901 proteins in vegetative cells of B. subtilis A163. Surprisingly, spore morphogenic protein SpoVM had no homologs in B. subtilis A163. Comparing protein expression between these two strains uncovered 108 proteins that were differentially present in spores and 93 proteins differentially present in cells. In addition, five of the seven proteins on an operon in strain A163, which is thought to be primarily responsible for this strain’s spores high heat resistance, were also identified. These findings reveal proteomic differences of the two strains exhibiting different resistance to heat and form a basis for further mechanistic analysis of the high heat resistance of B. subtilis A163 spores.

Entrepreneurs and Burnout. How Hardy Pesonality works in this process

2021 ◽  
pp. 003329412199697
Author(s):  
Laura Quiun ◽  
Marta Herrero ◽  
Maria del Carmen Yeo Ayala ◽  
Bernardo Moreno-Jiménez
Keyword(s):  
Emotional Exhaustion ◽  
Descriptive Analysis ◽  
Working Hours ◽  
Burnout Syndrome ◽  
Hierarchical Regression ◽  
Occupational Factors ◽  
Low Levels ◽  
And Performance ◽  
The Impact ◽  
The Relationship

Background Considering the importance of entrepreneurship and the impact of burnout on workers’ health, this study aims to explore the presence of burnout in entrepreneurs and the interaction of hardy personality (HP) in this process. Method The sample included 255 Spanish entrepreneurs. Occupational factors, working hours, labour immersion, HP, burnout syndrome (i.e. Emotional exhaustion, Depersonalization and Lack of accomplishment) and burnout consequences were assessed. Results Descriptive analysis showed that entrepreneurs had low levels of occupational factors, burnout syndrome and consequences. Hierarchical regression exploratory results indicated that working hours, labour immersion, and Emotional exhaustion were the most relevant predictors of the consequences. Besides, mediation models with PROCESS macro (v.3.0) highlighted the indirect effect of occupational factors and showed that emotional exhaustion was the only component of burnout that mediated in between the predictors and the consequences. As well, HP moderated the relationship between occupational factors and emotional exhaustion. Conclusions Occupational factors are the main predictor of burnout in entrepreneurs and HP could prevent their effect on Emotional exhaustion. The results suggest the importance of training to promote HP for better health and performance of entrepreneurs.

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