Castaing, J.-P., Lee, S., Anantharaman, V., Ravilious, G. E., Aravind, L. and Ramamurthi, K. S. (2014), An autoinhibitory conformation of the Bacillus subtilis spore coat protein SpoIVA prevents its premature ATP-independent aggregation. FEMS Microbiology Letters, 358: 145-153. doi: 10.1111/1574-6968.12452 ...
Bacteria are one of the premier biological forces that, in combination with chemical and physical forces, drive metal availability in the environment. Bacterial spores, when found in the environment, are often considered to be dormant and metabolically inactive, in a resting state waiting for favorable conditions for them to germinate. However, this is a highly oversimplified view of spores in the environment. The surface of bacterial spores represents a potential site for chemical reactions to occur. Additionally, proteins in the outer layers (spore coats or exosporium) may also have more specific catalytic activity. As a consequence, bacterial spores can play a role in geochemical processes and may indeed find uses in various biotechnological applications. The aim of this review is to introduce the role of bacteria and bacterial spores in biogeochemical cycles and their potential use as toxic metal bioremediation agents.
InterPro provides functional analysis of proteins by classifying them into families and predicting domains and important sites. We combine protein signatures from a number of member databases into a single searchable resource, capitalising on their individual strengths to produce a powerful integrated database and diagnostic tool.
Components of the bacterial spore germination apparatus are crucial for survival and for initiation of infection by some pathogens. While some components of the germination apparatus are well conserved in spore-forming species, such as the spoVA operon, each species may possess a different and possibly unique germinant recognition mechanism. The significance of several individual proteins in the germination process has been characterized. However, the mechanisms of how these proteins perform their functions and the network connecting these proteins in the complete germination process are still a mystery. In this study, we characterized a Bacillus subtilis superdormant spore population and investigated the abundance of 11 germination-related proteins. The relative quantities of these proteins in dormant, germinating and superdormant spores suggested that variation in the levels of proteins, other than germinant receptor proteins may result in superdormancy. Specifically, variation in the ...
Bacillus subtilis, as a model spore-forming Gram-positive bacterium, has been extensively used for spore germination research. Within this field, nutrient-dependent germination with specific germinant receptors (GerA, responding to L-alanine or L-valine; GerB and GerK, acting together to start spore germination process in response to AGFK) has been the most studied. There are three different variants of the GerAA subunit (299T/302S, 299A/302P, 299A/302S) of the GerA germination receptor present in B. subtilis subs. subtilis laboratory strains. According to our research, the 299A/302P one, unlike the others, interferes with the spores ability to germinate in L-alanine as assessed by the measurement of DPA release upon stimulation with the germinant. Multiple genetic manipulations described in this work followed by spore germination tests, together with secondary structure predictions led us to the following conclusions. First, position 302 of GerAA protein is crucial in terms of GerA germination
casSAR Dugability of P52969 | Su-2 | Small, acid-soluble spore protein 2 - Also known as SAS2_SPOUR, Su-2. SASP are bound to spore DNA. They are double-stranded DNA-binding proteins that cause DNA to change to an a-like conformation. They protect the DNA backbone from chemical and enzymatic cleavage and are thus involved in dormant spores high resistance to UV light.
Methods for enhancing destruction and killing of bacterial spores via phagocytosis, where phagocytosis of bacterial spores is enhanced by using a glycoconjugate. In one embodiment, the method includes the steps of modifying a surface of a bacterial spore to increase adherence to a phagocyte; and ingesting the adherence-increased spore with the phagocyte, thereby destructing and killing the spore by blocking spore-induced phagocyte cell death, while increasing phagocyte activation level and production of antimicrobial and cytocidal agents such as NO and inflammatory cytokines. The adherence of spore to a phagocyte is increased after the surface thereof is coated with a glycoconjugate to form a glycoconjugate-coated spores. The glycoconjugate-coated spores also increase ingestion of the spores by phagocytes and facilitate phagosome-lysosome fusion, which in turn results in destruction and killing of bacterial spores via phagocytosis. The method enhances
The Bacillus subtilis spore coat is composed of at least 15 polypeptides plus an insoluble protein fraction arranged in three morphological layers. The insoluble fraction accounts for about 30% of the coat protein and is resistant to solubilization by a variety of reagents, implying extensive cross-linking. A dodecapeptide was purified from this fraction by formic acid hydrolysis and reverse-phase high-performance liquid chromatography. This peptide was sequenced, and a gene designated cotX was cloned by reverse genetics. The cotX gene encoding the dodecapeptide at its amino end was clustered with four other genes designated cotV, cotW, cotY, and cotZ. These genes were mapped to 107 degrees between thiB and metA on the B. subtilis chromosome. The deduced amino acid sequences of the cotY and cotZ genes are very similar. Both proteins are cysteine rich, and CotY antigen was present in spore coat extracts as disulfide cross-linked multimers. There was little CotX antigen in the spore coat soluble ...
Bakterid moodustavad endospoore enda sees. Spoorid on ümbritsetud õhukese kihiga ehk eksiiniga. Eksiini all paikneb paks valguline spoorimantel ehk eksospoorium, mis on läbitungimatu mitmetele suurtele toksilistele molekulidele. See kest on peamiselt üles ehitatud valgujääkidest. Lisaks paiknevad seal ka ensüümid, mis on bakteri arengu käigus tekkinud. Spoori kesta all asub korteks (koor, koorik), mis koosneb peptidoglükaanist. Korteks tagab resistentsuse ekstreemsetes kliimatingimustes. Neljanda kihina paikneb korteksi all tuuma sein, mis ümbritseb endospoori tuuma ehk protoblasti. Tuuma sein sisaldab kromosomaalset DNA-d, mida ümbritsevad kromatiinisarnased valgud ehk SASP-d (inglise: small acid-soluble spore proteins). Lisaks sisaldab tuuma sein ribosoome ja teisi ensüüme, kuid nad ei ole metaboolselt aktiivsed.[5] Kaltsium-dipikolinaat moodustab kuni 15% endospooride kuivmassist. Dipikoliinhape ja kaltsium kaitsevad spoori kuuma eest ning viimane neist ka oksüdeerivate ...
Endospore Stain The endospore stain is a differential stain used to visualize bacterial endospores. Endospores are formed by a few genera of bacteria, such as Bacillus . By forming spores, bacteria can survive in hostile conditions. Spores are resistant to heat, dessication, chemicals, and radiation. Bacteria can form endospores in approximately 6 to 8 hours after being exposed to adverse conditions. The normally-growing cell that forms the endospore is called a vegetative cell. Spores are metabolically inactive and dehydrated. They can remain viable for thousands of years. When spores are exposed to favorable conditions, they can germinate into a vegetative cell within 90 minutes. Endospores can form within different areas of the vegetative cell. They can be central, subterminal, or terminal. Central endospores are located within the middle of the vegetative cell. Terminal endospores are located at the end of the vegetative cell. Subterminal endospores are located between the middle and the end ...
Rapid isolation and identification of spores from various environmental samples is necessitated because anthrax spores can be used as biological weapons. The hydrophobic nature of spores may allow for their rapid concentration and partial purification from contaminating materials. In this study, spores from four taxonomic groups of Bacillaceae were isolated, purified and characterized for hydrophobicity by hexadecane partitioning, surface morphology by scanning electron microscopy, and steady-state fluorescence by spectroscopy. The morphology of spores was similar within taxonomic groups and dissimilar between groups. Spore hydrophobicity ranged from 0.3% to 65% and all spores had fluorescence emission peaks at 335 nm and 450 nm. The excitation maxima for the peak at 450 nm were shifted to higher wavelengths for the least hydrophobic spores. Regression analysis demonstrated a correlation between the taxonomic identity, as established by fatty acid analyses, and hydrophobicity. Hydrophobicity can
Early in the process of spore formation in Bacillus subtilis a septum is formed that partitions the sporangium into daughter cells called the forespore and the mother cell. The daughter cells each have their own chromosome but follow dissimilar programs of gene expression. Differential gene expression in the forespore is now shown to be established by the compartmentalized activity of the transcription factor sigma F. The sigma F factor is produced prior to septation, but is active only in the forespore compartment of the post-septation sporangium. The sigma F factor is controlled by the products of sporulation operons spoIIA and spoIIE, which may be responsible for confining its activity to one of the daughter cells. ...
Genes encoding proteins in a common regulatory network are frequently located close to one another on the chromosome to facilitate co-regulation or couple gene expression to growth rate. Contrasting with these observations, here, we demonstrate a functional role for the arrangement of Bacillus subtilis sporulation network genes on opposite sides of the chromosome. We show that the arrangement of two sporulation network genes, one located close to the origin and the other close to the terminus, leads to a transient gene dosage imbalance during chromosome replication. This imbalance is detected by the sporulation network to produce cell-cycle coordinated pulses of the sporulation master regulator Spo0A∼P. This pulsed response allows cells to decide between sporulation and continued vegetative growth during each cell cycle spent in starvation. The simplicity of this coordination mechanism suggests that it may be widely applicable in a variety of gene regulatory and stress-response settings ...
We are particularly interested in understanding the molecular mechanisms of spore germination, which dormant spores undergo when stimulated to return to the vegetative state. We are also interested in the composition and assembly of the spore coat and exosporium, and aim to define the structures and functions of the various proteins that form this primary protective barrier.. We use a range of approaches to gain insight to spore biology at the molecular level, including genetic, biochemical, crystallographic and advanced imaging techniques.. Overall, our objective is to consider fundamental insights to spore structure and physiology in the context of public health, food safety, counter-terrorism and environmental decontamination, and to determine how such information might then be applied to improve current capabilities in these sectors.. Enquiries concerning post-graduate research opportunities, industrial collaborations, or general information concerning the groups activities, should be ...
Spore-forming bacteria are common contaminants of food, and represent a major source of food poisoning and food spoilage (1, 2). Bacterial cells in their vegetative or sporulated forms can be found in the environment and therefore can be natural contaminants of raw materials. The sporeformers display many physiological and enzymatic capacities. The spores are metabolically inactive, but they are commonly resistant to physical and chemical treatments applied in the food industry. In contrast, vegetative cells are more sensitive to stress, are physiologically active, and can produce degradative enzymes or toxins, form biofilms, and differentiate into resistant spores.. The aim for industrials is to limit or even avoid the presence of sporeformers in their final products and on food lines. To do so, curative means can be used, such as cleaning and whitening processes on raw materials or physical treatments, in order to reduce the load of sporeformers. Preventive means are also used in order to ...
Receptor-based detection of pathogens often suffers from non-specific interactions, and as most detection techniques cannot distinguish between affinities of interactions, false positive responses remain a plaguing reality. Here, we report an anharmonic acoustic based method of detection that addresses the inherent weakness of current ligand dependant assays. Spores of Bacillus subtilis (Bacillus anthracis simulant) were immobilized on a thickness-shear mode AT-cut quartz crystal functionalized with anti-spore antibody and the sensor was driven by a pure sinusoidal oscillation at increasing amplitude. Biomolecular interaction forces between the coupled spores and the accelerating surface caused a nonlinear modulation of the acoustic response of the crystal. In particular, the deviation in the third harmonic of the transduced electrical response versus oscillation amplitude of the sensor (signal) was found to be significant. Signals from the specifically-bound spores were clearly distinguishable ...
Bacterial spore formers have been the focus of intense study for almost half a century. The most heavily studied of these is Bacillus subtilis, an internationally recognized model organism, whose physiology, biochemistry and genetics have been studied for many years. Under nutrient rich conditions, B. subtilis grows and multiplies by a process of cell expansion followed by division at mid-cell to generate identical daughter cells; however, B. subtilis also has the ability to form spores, dormant cells which are resistant to many of the chemical and physical challenges that normally kill bacteria. Although many of the basic aspects of this process are now well understood, bacterial sporulation still remains a highly attractive model for studying various cell processes at a molecular level. There are several reasons for this interest. First, some of the more complex sporulation steps are not fully understood or are only described using controversial models. Second, the extensive attention lavished on
process of spore formation for sale - 57 - process of spore formation wholesalers & process of spore formation manufacturers from China manufacturers.
Recent experiments suggest that in the bacterium, B. subtilis, the cue for the localization of small sporulation protein, SpoVM, that plays a central role in spore coat formation, is curvature of the bacterial plasma membrane. This curvature-dependent localization is puzzling given the orders of magnitude difference in lengthscale of an individual protein and radius of curvature of the membrane. Here we develop a minimal model to study the relationship between curvature-dependent membrane absorption of SpoVM and clustering of membrane-associated SpoVM and compare our results with experiments. To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2012.MAR.B41.9. ...
A microbiological study on treated waste from a microwave unit can be done for various test organisms like Bacillus subtilis, Pseudomonas aeruginosa, Staphlococcus aureus, E Coli, Candida albicans, Mycobacterium tuberculosis, Geo Bacillus Sterothermophilis to name a few.. • The bacterial spores are most resistant to heat and their inactivation indicates that the system is capable of inactivating virtually all types of micro organisms.. • Self contained Biological Indicator ampoules, with a spore population of 105, for bacillus subtilis or Geo Bacilus Stero thermophilis are readily available in the market.. • These SCBI ampoules for Geo Bacilus Stero thermophilis can be placed in the Maser Bin , amidst waste to be treated. Once treated, suspension from these ampoules are incubated at 370 C for 48-72 hours and observed for growth, if any.. • No growth after incubation, indicates that the organisms are inactivated and hence the required disinfection achieved successfully. ...
During the process of sporulation, a/α diploids degrade about 50% of their vegetative proteins. This degradation is not sporulation specific, for asporogenous diploids of a/a mating type degrade their vegetative proteins in a fashion similar to that of their a/α counterparts. Diploids lacking carboxypeptidase Y activity, prc1/prc1, show about 80% of wild-type levels of protein degradation, but are unimpaired in the production of normal asci. Diploids lacking proteinase B activity, prb1/prb1, show about 50% of wild-type levels of protein degradation. The effect on degradation of the proteinase B deficiency is epistatic to the degradation deficit attributable to the carboxypeptidase Y deficiency. The prb1 homozygotes undergo meiosis and produce spores, but the asci and, possibly, the spores are abnormal. Diploids homozygous for the pleiotropic pep4-3 mutation show only 30% of the wild-type levels of degradation when exposed to a sporulation regimen, and do not undergo meiosis or sporulation. ...
osw mutant spores are sensitive to digestion by β-glucanases.AN120 (wild type) and the indicated osw mutant strains were sporulated and the survival of the spo
A longstanding challenge in developmental biology is to understand how organisms construct large structures that ultimately help define how that organism looks. We are approaching this problem by examining the morphogenesis of a simple organism, a bacterial spore, and are trying to understand how it achieves its characteristic morphology. Spores are dormant cell types that are encased in a thick protein shell, termed the "coat". Spores are highly resistant to environmental insults, and this resistance is due, in part, to the protective properties of the coat. Assembly of the basement layer of the coat depends on a tiny protein, called SpoVM, which anchors the coat onto the surface of the developing spore. We have discovered that SpoVM localizes properly by preferentially embedding in convex, or positively curved, membranes, such as those found on the surface of the spore. SpoVM then recruits a novel cytoskeletal protein, called SpoIVA, which polymerizes by hydrolyzing ATP to form a stable ...
Members of this protein family represent a subset of those belonging to Pfam family PF00188 (SCP-like extracellular protein). Based on currently cuttoffs for this model, all member proteins are found in Bacteria capable of endospore formation. Members include a named but uncharacterized protein, YkwD of Bacillus subtilis. Only the C-terminal region is well-conserved and is included in the seed alignment for this model. Three members of this family have an N-terminal domain homologous to the spore coat assembly protein SafA ...
I am about to inoculate a few jars but they were kinda warm from being in my car today and i was wondering if it would be ok to proceed. What temperature is the highest the spore can be placed in
For serious infections caused by Bacillus and Clostridia species the contagion is often the spore not the vegetative bacillus and represents an intervention poi...
The life cycle of a fungus includes a fruiting structure that produces spores, the spores themselves and the germination of spores into a new fungus. The exact mechanism differs between sexual and...
The terms mold and mildew actually refer to the same thing. Both refer to a colony of fungus that grows in damp, dark areas. Mildew is usually used when referring to a slimy, flat colony, but this has more to do with amount of moisture in the area than the type of mold. For this reason, a mold air purifier is the same as a mildew air purifier - in both cases, removal of spores from the air is the key element. Molds produce spores as a way to spread. These tiny seeds cannot be seen by the naked eye, except when there are so many they will appear as a smoky cloud. The spores range in size from 1 to 100 microns in size. They are single cells expelled by the colony, usually when conditions for growth change. A colony will grow (often invisibly) until it begins to deplete the available resources Read more [...] ...
The Genus Clostridium Consists Of Over 295 Species Of Gram- Positive, Rod-shaped Bacteria. These Are Mostly Anaerobes And Present Ubiquitously In The Environment Due To Their Ability To Form Heat, Radiation And Chemical Resistant Spores. In This Book, The Authors Present Current Research In The Stud... Lees verder ...
Ion-control gene spo0M (6.5-fold); pksA (6.7-fold), which codes for a transcriptional regulator of polyketide synthase; and yceD (3.7-fold), which is similar to
MichaelXYs links at least indicate that the bacterial load in the air is relatively small. (And after all, why wouldnt it - most bacteria dont produce spores specifically meant for airborne spreading as far as I know) I thought fungal spores, on the other hand, wouldve been much more common in the air, but at least quick googling* gave me values ranging from 50 to 500 CFU/m3, which is quite close to the amount of bacteria ...
The Developmental Research Program has been one of the most valuable and productive of the SPORE components. The development of innovative translational researc...
From GenBANK (gi:14194729): Exonuclease VII bidirectionally degrades single-stranded DNA into large acid-insoluble oligonucleotides, which are then degraded further into small acid-soluble oligonucleotides. Its catalytic activity is exonucleolytic cleavage in either 5-to 3-or 3-to 5-direction to yield 5-phosphomononucleotides. The complex is a heterooligomer composed of large and small subunits (by similarity ...
Kerstin Voelz investigates how fungal pathogens circumvent and hijack innate immune responses to establish disease using a zebrafish larval model. In particular she aims to decode how fungi initiate spore germination, why the immune system sometimes fails to inhibit this process and how this can be prevented ...
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Zinc release is the first quantitatively significant event detected during the triggering of Bacillus megaterium KM spore germination. Of the total spore Zn2+ pool 25% is released from non-heat-activated spores within 4 min of triggering germination. During this period only 10% of the spore population becomes irreversibly committed to germinate. The investigation of a putative role for Zn2+ in the germination trigger mechanism has established a relationship between the rate and extent of Zn2+ release and the stimulation of spore germination by heat activation. Furthermore, a correlation can be demonstrated between the extent of zinc release from spore populations and the time required to obtain 50% commitment of these populations to germinate over a wide temperature range. These findings have been used to expand a recently published model for the triggering of bacterial spore germination. ...
There is still great interest in controlling bacterial endospores. The use of chemical disinfectants and, notably, oxidizing agents to sterilize medical devices is increasing. With this in mind, hydrogen peroxide (H2O2) and peracetic acid (PAA) have been used in combination, but until now there has been no explanation for the observed increase in sporicidal activity. This study provides information on the mechanism of synergistic interaction of PAA and H2O2 against bacterial spores. We performed investigations of the efficacies of different combinations, including pretreatments with the two oxidizers, against wild-type spores and a range of spore mutants deficient in the spore coat or small acid-soluble spore proteins. The concentrations of the two biocides were also measured in the reaction vessels, enabling the assessment of any shift from H2O2 to PAA formation. This study confirmed the synergistic activity of the combination of H2O2 and PAA. However, we observed that the sporicidal activity ...
TY - JOUR. T1 - Inactivation of chemical and heat-resistant spores of Bacillus and Geobacillus by nitrogen cold atmospheric plasma and comparison to thermal and chemical based methods. AU - van Bokhorst-van de Veen, H.. AU - Xie, H.. AU - Esveld, D.C.. AU - Abee, T.. AU - Mastwijk, H.C.. AU - Nierop Groot, M.N.. PY - 2015. Y1 - 2015. N2 - Bacterial spores are resistant to severe conditions and form a challenge to eradicate from food or food packaging material. Cold atmospheric plasma (CAP) treatment is receiving more attention as potential sterilization method at relatively mild conditions but the exact mechanism of inactivation is still not fully understood. In this study, the biocidal effect by nitrogen CAP was determined for chemical (hypochlorite and hydrogen peroxide), physical (UV) and heat-resistant spores. The three different sporeformers used are Bacillus cereus a food-borne pathogen, and Bacillus atrophaeus and Geobacillus stearothermophilus that are used as biological indicators for ...
Heat shock of dormant spores of Bacillus stearothermophilus ATCC 7953 at 100 or 80 degrees C for short times, the so-called activation or breaking of dormancy, was investigated by separating the resulting spores by buoyant density centrifugation into a band at 1.240 g/ml that was distinct from another band at 1.340 g/ml, the same density as the original spores. The proportion of spores at 1.240 g/ml became larger when the original dormant spores were heated for a longer period of time, but integument-stripped dormant spores were quickly and completely converted to spores with a band at 1.240 g/ml. The spores with bands at both 1.240 and 1.340 g/ml were germinable faster than the original dormant spores and thus were considered to be activated. The spores with a band at 1.240 g/ml, which were considered to be fully activated, were apparently permeabilized, with a resulting complete depletion of dipicolinic acid, partial depletion of minerals, susceptibility to lysozyme action, permeation of the ...
Spores of foodborne pathogens such as Clostridium botulinum, Clostridium perfringens and Bacillus cereus are widely distributed in nature. Presence of those spores in food products, particularly C. botulinum spores in vacuum packed, ready-to-eat low-acid products, is a great safety concern. The research here described is a first effort towards understanding the role of the spore coat proteins in the inactivation of bacterial spore using high pressure processing. This study proposes a coat protein solubilization methodology using non-ionic detergents minimizing protein damage and compatible with spectroscopy methods. The methodology developed here was compared with approaches proposed in the literature with respect to protein yield, protein fractions identified, amino acid composition and suitability with spectroscopy techniques for the further analysis of coat proteins. Bacillus subtilis ATCC 6633 spore coat proteins were solubilized (n=3) using octyl-β-D-glucopyranoside (OGP) at room ...
Effective killing of Bacillus anthracis spores is of paramount importance to antibioterrorism, food safety, environmental protection, and the medical device industry. Thus, a deeper understanding of the mechanisms of spore resistance and inactivation is highly desired for developing new strategies or improving the known methods for spore destruction. Previous studies have shown that spore inactivation mechanisms differ considerably depending upon the killing agents, such as heat (wet heat, dry heat), UV, ionizing radiation, and chemicals. It is believed that wet heat kills spores by inactivating critical enzymes, while dry heat kills spores by damaging their DNA. Many studies have focused on the biochemical aspects of spore inactivation by dry heat; few have investigated structural damages and changes in spore mechanical properties. In this study, we have inactivated Bacillus anthracis spores with rapid dry heating and performed nanoscale topographical and mechanical analysis of inactivated spores using
The ability of Clostridium perfringens to form spores plays a key role during the transmission of this Gram-positive bacterium to cause disease. Of particular note, the spores produced by food poisoning strains are often exceptionally resistant to food environment stresses such as heat, cold, and preservatives, which likely facilitates their survival in temperature-abused foods. The exceptional resistance properties of spores made by most type A food poisoning strains and some type C foodborne disease strains involve their production of a variant small acid-soluble protein-4 that binds more tightly to spore DNA than to the small acid-soluble protein-4 made by most other C. perfringens strains. Sporulation and germination by C. perfringens and Bacillus spp. share both similarities and differences. Finally, sporulation is essential for production of C. perfringens enterotoxin, which is responsible for the symptoms of C. perfringens type A food poisoning, the second most common bacterial foodborne disease
A newly published research study by scientists at the UK Institute of Food Research (IFR) has identified part of the mechanism by which the resistant endospores of the dangerous foodborne pathogen Clostridium botulinum (the cause of botulism) are able to germinate.. It is known that spore germination is initiated when certain small molecules (germinants) are recognised by a specific germinant receptors (GR) located in the inner membrane of the spore. The IFR researchers were able to identify two active GRs in the spores of Cl. botulinum, which respond to amino acid germinants and act in synergy, but are unable to function alone. Other GRs form a complex that seems to play a role in controlling the speed of germination.. The authors of the study say that understanding the germination mechanism of Cl. botulinum spores is essential if new control measures to prevent germination and subsequent toxin production by vegetative cells in food are to be developed. They suggest that it may be possible to ...
Author summary The anaerobic, spore-forming bacterium Clostridium difficile (C. difficile) is a prominent pathogen in hospitals worldwide and the leading cause of nosocomial diarrhea. Numerous risk factors are associated with C. difficile infections (CDIs) including: antibiotics, advanced age, vitamin D deficiency, and proton pump inhibitors. Antibiotic use disrupts the intestinal microbiota allowing for C. difficile to colonize, however, why these other risk factors increase CDI incidence is unclear. Notably, deficient intestinal calcium absorption (i.e., increased calcium levels) is associated with these risk factors. In this work, we investigate the role of calcium in C. difficile spore germination. C. difficile spores are the infectious particles and they must become metabolically active (germinate) to cause disease. Here, we show that calcium is required for C. difficile germination, specifically activating the key step of cortex hydrolysis, and that this calcium can be derived from either within
Inactivation kinetics for Bacillus subtilis endospores for (△) pure argon, () argon + 0.135% vol. oxygen, () argon + 0.135% vol. oxygen + 0.2% vol. nitrogen i
Author Summary Positive auto-regulation of a transcriptional activator during cell differentiation or development often allows the rapid and robust deployment of cell- and stage-specific genes and the routing of the differentiating cell down a specific path. Positive auto-regulation however, raises the potential for inappropriate activity of the transcription factor. Here we unravel the role of a previously characterized anti-sigma factor, CsfB, in a negative feedback loop that prevents ectopic expression of the sporulation-specific sigma factor σG of Bacillus subtilis. σG is activated in the forespore, one of the two chambers of the developing cell, at an intermediate stage in spore development. Once active, a positive feedback loop allows the rapid accumulation of σG. Synthesis of both σG and CsfB is under the control of the early forespore regulator σF, and CsfB may help prevent the premature activity of σG in the forespore. However, CsfB is also produced under σG control in non-sporulating
1. When Bacillus subtilis was grown in a medium in which sporulation occurred well-defined morphological changes were seen in thin sections of the cells. 2. Over a period of 7·5hr. beginning 2hr. after the initiation of sporulation the following major stages were observed: axial nuclear-filament formation, spore-septum formation, release of the fore-spore within the cell, development of the cortex around the fore-spore, the laying down of the spore coat and the completion of the corrugated spore coat before release of the spore from the mother cell. 3. The appearance of refractile bodies and 2,6-dipicolinic acid and the development of heat-resistance began between 5 and 6·5hr. after initiation of sporulation. 4. The appearance of 2,6-dipicolinic acid and the onset of refractility appeared to coincide with a diminution of electron density in the spore core and cortex. 5. Heat-resistance was associated with the terminal stage, the completion of the spore coat. 6. The spore coat was composed of ...
Bacillus anthracis forms one endospore per cell. Its spores form when its non reproductive cells are in need of specific nutrients . The spores are oval in shape and sporulation occurs within 48 hours. Bacillus anthracis requires oxygen to sporulate. Spores can tolerate heat, cold, dehydration, radiation and even antibacterials (8). The formation of spore commences when cells septate asymmetrically to create a forespore and a mother cell. After septation, the mother cell swallows the forespore and covers it with different layers. The spore is made up of several layers. These layers are the coat, the exosporium and the cortex (Figure 3). The innermost layer is the core. It contains proteins which holds the chromosome. Half of the spore is composed of the spore coat. The flexibility of the spore coat enable the spore to hold the core during germination. It protects the spore from harmful chemicals and aids germination. The cortex containing peptidoglycan protects the spore from radiation, heat and ...
Spores of Bacillus subtilis are being used as probiotics and competitive exclusion agents for animal consumption. Commercial production media often include relatively expensive components of animal origin that are a potential source for the presence of adventious agents, therefore undesirable for use in production scale. In this study a new animal-free component, chemically defined medium, was tested for B. subtilis spore production. Medium composition was optimized with respect to vitamin composition, carbon, nitrogen and calcium concentrations. A fed-batch bioprocess was developed, being the effect on sporulation of the carbon to nitrogen ratio at the end of the exponential growth phase studied. The developed strategy consisted of an initial and a final batch phase and an intermediate fed-batch phase with the addition of a feeding solution containing glucose and calcium and the addition of a feeding solution of ammonium sulphate, using an exponential and a constant feeding profile,
Bacillus anthracis forms one endospore per cell. Its spores form when its non reproductive cells are deficient of certain nutrients . The spores are oval in shape and sporulation occurs within 48 hours. Bacillus anthracis requires oxygen to sporulate. Spores can tolerate heat, cold, dehydration, radiation and even antibacterials [8]. The formation of spore commences when cells septate asymmetrically to create a forespore and a mother cell. After septation, the mother cell swallows the forespore and covers it with different layers. The spore is made up of several layers. These layers are the coat, the exosporium and the cortex. Figure 3 reveals these layers through a transmission electron micrograph. The innermost layer is the core. It contains proteins which holds the chromosome. Half of the spore is composed of the spore coat. The flexibility of the spore coat enables the spore to hold the core especially during germination. It protects the spore from harmful chemicals and aids germination. The ...