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.

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.

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.

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.

Role of ribosidase in germination of Bacillus cereus T spores induced.

1985 ◽  
Vol 40 (3) ◽  
pp. 581-587 ◽  
Author(s):  
Hirofumi SHIBATA ◽  
Noriaki OHNISHI ◽  
Keiko TAKEDA ◽  
Isamu TANI
Keyword(s):  
Bacillus Cereus

scholarly journals Investigating the Feasibility of Mefenamic Acid Nanosuspension for Pediatric Delivery: Preparation, Characterization, and Role of Excipients

Processes ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 574
Author(s):  
Nikhat Perween ◽  
Sultan Alshehri ◽  
T. S. Easwari ◽  
Vivek Verma ◽  
Md. Faiyazuddin ◽  
...  
Keyword(s):  
Particle Size ◽  
Mefenamic Acid ◽  
Hydroxypropyl Methylcellulose ◽  
Sodium Dodecyl ◽  
Aqueous Solubility ◽  
Oral Route ◽  
Precipitation Method ◽  
Antisolvent Precipitation

Molecules with poor aqueous solubility are difficult to formulate using conventional approaches and are associated with many formulation delivery issues. To overcome these obstacles, nanosuspension technology can be one of the promising approaches. Hence, in this study, the feasibility of mefenamic acid (MA) oral nanosuspension was investigated for pediatric delivery by studying the role of excipients and optimizing the techniques. Nanosuspensions of MA were prepared by adopting an antisolvent precipitation method, followed by ultrasonication with varying concentrations of polymers, surfactants, and microfluidics. The prepared nanosuspensions were evaluated for particle size, morphology, and rheological measures. Hydroxypropyl methylcellulose (HPMC) with varying concentrations and different stabilizers including Tween® 80 and sodium dodecyl sulfate (SLS) were used to restrain the particle size growth of the developed nanosuspension. The optimized nanosuspension formula was stable for more than 3 weeks and showed a reduced particle size of 510 nm with a polydispersity index of 0.329. It was observed that the type and ratio of polymer stabilizers were responsive on the particle contour and dimension and stability. We have developed a biologically compatible oral nanoformulation for a first-in-class drug beautifully designed for pediatric delivery that will be progressed toward further in vivo enabling studies. Finally, the nanosuspension could be considered a promising carrier for pediatric delivery of MA through the oral route with enhanced biological impact.

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.

scholarly journals Studies on the Role of the are a Gene in the Regulation of Nitrogen Catabolism in Aspergillus nidulans

1975 ◽  
Vol 28 (3) ◽  
pp. 301 ◽  
Author(s):  
MJ Hynes
Keyword(s):  
Nitrogen Source ◽  
Aspergillus Nidulans ◽  
Carbon Sources ◽  
Nitrogen Sources ◽  
Selection Methods ◽  
Growth Responses ◽  
Dominance Relationships ◽  
Regulatory Circuits ◽  
Specific Activities

Mutants of Apergillus nidulanswith lesions in a gene, areA (formerly called amdT), have been isolated by a variety of different selection methods. The areA mutants show a range of pleiotropic growth responses to a number of compounds as sole nitrogen sources, but are normal in utilization of carbon sources. The levels of two amidase enzymes as well as urease have been investigated in the mutants and have been shown to be affected by this gene. Most of the areA mutants have much lower amidase-specific activities when grown in ammonium-containing medium, compared with mycelium incubated in medium la9king a nitrogen source. Some of the areA. mutants do not show derepression of urease upon relief of ammonium repression. The dominance relationships of areA alleles have been investigated in� heterozygous diploids, and these studies lend support to the proposal that areA codes for a positively acting regulatory product. One of the new areA alleles is partially dominant to areA + and areA102. This may be a result of negative complementation or indicate that areA has an additional negative reiuIatory function. Investigation.of various amdR; areA double mutants has led to the conclusion that amdR and areA participate in independent regulatory circuits in the control of acetamide utilizatiol1. Studies on an amdRc; areA.double mutant indicate that areA is involved in derepression of acetamidase upon relief of ammo.nium repression.

scholarly journals Potentiating Effect of Mandelate and Lactate on Chemically Induced Germination in Members of Bacillus cereus Sensu Lato

2017 ◽  
Vol 83 (24) ◽  
Author(s):  
Alistair H. Bishop
Keyword(s):  
Bacillus Cereus ◽  
Large Scale ◽  
Germination Rate ◽  
Dependent Manner ◽  
Clostridium Sporogenes ◽  
Specific Chemical ◽  
Content Type ◽  
Ph Range ◽  
Significant Discovery ◽  
The Impact

ABSTRACT Endospores of the genus Bacillus can be triggered to germinate by a limited number of chemicals. Mandelate had powerful additive effects on the levels and rates of germination produced in non-heat-shocked spores of Bacillus anthracis strain Sterne, Bacillus cereus, and Bacillus thuringiensis when combined with l-alanine and inosine. Mandelate had no germinant effect on its own but was active with these germinants in a dose-dependent manner at concentrations higher than 0.5 mM. The maximum rate and extent of germination were produced in B. anthracis by 100 mM l-alanine with 10 mM inosine; this was equaled by just 25% of these germinants when supplemented with 10 mM mandelate. Half the maximal germination rate was produced by 40% of the optimum germinant concentrations or 15% of them when supplemented with 0.8 mM mandelate. Germination rates in B. thuringiensis were highest around neutrality, but the potentiating effect of mandelate was maintained over a wider pH range than was germination with l-alanine and inosine alone. For all species, lactate also promoted germination in the presence of l-alanine and inosine; this was further increased by mandelate. Ammonium ions also enhanced l-alanine- and inosine-induced germination but only when mandelate was present. In spite of the structural similarities, mandelate did not compete with phenylalanine as a germinant. Mandelate appeared to bind to spores while enhancing germination. There was no effect when mandelate was used in conjunction with nonnutrient germinants. No effect was produced with spores of Bacillus subtilis, Clostridium sporogenes, or C. difficile. IMPORTANCE The number of chemicals that can induce germination in the species related to Bacillus cereus has been defined for many years, and they conform to specific chemical types. Although not a germinant itself, mandelate has a structure that is different from these germination-active compounds, and its addition to this list represents a significant discovery in the fundamental biology of spore germination. This novel activity may also have important applied relevance given the impact of spores of B. cereus in foodborne disease and B. anthracis as a threat agent. The destruction of spores of B. anthracis, for example, particularly over large outdoor areas, poses significant scientific and logistical problems. The addition of mandelate and lactate to the established mixtures of l-alanine and inosine would decrease the amount of the established germinants required and increase the speed and level of germination achieved. The large-scale application of “germinate to decontaminate” strategy may thus become more practicable.

scholarly journals Role of SpoVA Proteins in Release of Dipicolinic Acid during Germination of Bacillus subtilis Spores Triggered by Dodecylamine or Lysozyme

2006 ◽  
Vol 189 (5) ◽  
pp. 1565-1572 ◽  
Author(s):  
Venkata Ramana Vepachedu ◽  
Peter Setlow
Keyword(s):  
Bacillus Subtilis ◽  
Small Molecules ◽  
Spore Germination ◽  
Dipicolinic Acid ◽  
Temperature Sensitive ◽  
Wild Type ◽  
Ph Optimum ◽  
Inner Membrane ◽  
Temperature Sensitive Mutants

ABSTRACT The release of dipicolinic acid (DPA) during the germination of Bacillus subtilis spores by the cationic surfactant dodecylamine exhibited a pH optimum of ∼9 and a temperature optimum of 60°C. DPA release during dodecylamine germination of B. subtilis spores with fourfold-elevated levels of the SpoVA proteins that have been suggested to be involved in the release of DPA during nutrient germination was about fourfold faster than DPA release during dodecylamine germination of wild-type spores and was inhibited by HgCl2. Spores carrying temperature-sensitive mutants in the spoVA operon were also temperature sensitive in DPA release during dodecylamine germination as well as in lysozyme germination of decoated spores. In addition to DPA, dodecylamine triggered the release of amounts of Ca2+ almost equivalent to those of DPA, and at least one other abundant spore small molecule, glutamic acid, was released in parallel with Ca2+ and DPA. These data indicate that (i) dodecylamine triggers spore germination by opening a channel in the inner membrane for Ca2+-DPA and other small molecules, (ii) this channel is composed at least in part of proteins, and (iii) SpoVA proteins are involved in the release of Ca2+-DPA and other small molecules during spore germination, perhaps by being a part of a channel in the spore's inner membrane.

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