scholarly journals Sporulation in Bacillus subtilis. Morphological changes

1968 ◽  
Vol 109 (5) ◽  
pp. 819-824 ◽  
Author(s):  
D. Kay ◽  
S. C. Warren
Keyword(s):  
Bacillus Subtilis ◽  
Heat Resistance ◽  
Early Stage ◽  
Morphological Changes ◽  
Dipicolinic Acid ◽  
Close Contact ◽  
Spore Coat ◽  
Serial Sections ◽  
Filament Formation ◽  
Thin Sections

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 an inner and an outer layer, each of which consisted of three or four electron-dense laminae. 7. Serial sections through cells at an early stage of sporulation showed that the membranes of each spore septum were always continuous with the membranes of a mesosome, which was itself in close contact with the bacterial or spore nucleoid. 8. These changes were correlated with biochemical events occurring during sporulation.

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 A dynamic, ring-forming MucB / RseB-like protein influences spore shape in Bacillus subtilis

PLoS Genetics ◽  
2020 ◽  
Vol 16 (12) ◽  
pp. e1009246
Author(s):  
Johana Luhur ◽  
Helena Chan ◽  
Benson Kachappilly ◽  
Ahmed Mohamed ◽  
Cécile Morlot ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Fluorescence Microscopy ◽  
Mother Cell ◽  
Morphological Changes ◽  
Cell Envelope ◽  
Genetic Relationships ◽  
Protein Domain ◽  
Phenotypic Characterization ◽  
Spore Coat ◽  
3D Fluorescence Microscopy

How organisms develop into specific shapes is a central question in biology. The maintenance of bacterial shape is connected to the assembly and remodelling of the cell envelope. In endospore-forming bacteria, the pre-spore compartment (the forespore) undergoes morphological changes that result in a spore of defined shape, with a complex, multi-layered cell envelope. However, the mechanisms that govern spore shape remain poorly understood. Here, using a combination of fluorescence microscopy, quantitative image analysis, molecular genetics and transmission electron microscopy, we show that SsdC (formerly YdcC), a poorly-characterized new member of the MucB / RseB family of proteins that bind lipopolysaccharide in diderm bacteria, influences spore shape in the monoderm Bacillus subtilis. Sporulating cells lacking SsdC fail to adopt the typical oblong shape of wild-type forespores and are instead rounder. 2D and 3D-fluorescence microscopy suggest that SsdC forms a discontinuous, dynamic ring-like structure in the peripheral membrane of the mother cell, near the mother cell proximal pole of the forespore. A synthetic sporulation screen identified genetic relationships between ssdC and genes involved in the assembly of the spore coat. Phenotypic characterization of these mutants revealed that spore shape, and SsdC localization, depend on the coat basement layer proteins SpoVM and SpoIVA, the encasement protein SpoVID and the inner coat protein SafA. Importantly, we found that the ΔssdC mutant produces spores with an abnormal-looking cortex, and abolishing cortex synthesis in the mutant largely suppresses its shape defects. Thus, SsdC appears to play a role in the proper assembly of the spore cortex, through connections to the spore coat. Collectively, our data suggest functional diversification of the MucB / RseB protein domain between diderm and monoderm bacteria and identify SsdC as an important factor in spore shape development.

scholarly journals Commitment to sporulation in Bacillus subtilis and its relationship to development of actinomycin resistance

1969 ◽  
Vol 113 (1) ◽  
pp. 29-37 ◽  
Author(s):  
Janet M. Sterlini ◽  
J. Mandelstam
Keyword(s):  
Alkaline Phosphatase ◽  
Bacillus Subtilis ◽  
Heat Resistance ◽  
Messenger Rna ◽  
Actinomycin D ◽  
Dipicolinic Acid ◽  
Vegetative State ◽  
Single Point

1. Experiments to determine the point of commitment to sporulation were carried out by restoring nutrients at different times to suspensions of sporulating Bacillus subtilis. 2. No single point of commitment to the process as a whole was found. Instead, the cells became committed in turn to the following successive events connected with sporulation: formation of alkaline phosphatase, development of refractility, synthesis of dipicolinic acid and development of heat-resistance. 3. Each point of commitment was followed within about 30min. by a period in which the event concerned ceased to be inhibited by actinomycin D. 4. The implication of these results is that each point of commitment is probably due to the formation of a species of long-lived messenger RNA and that, in any case, sporulation is regulated at the level of both transcription and translation. 5. It is also shown that sporulation and growth are perhaps not mutually exclusive functions and that histidase, an enzyme typical of the vegetative state, can be induced in sporulating suspensions.

Ultrastructural aspects of spore germination and outgrowth in Clostridium sporogenes

1969 ◽  
Vol 15 (9) ◽  
pp. 1061-1065 ◽  
Author(s):  
Judith F. M. Hoeniger ◽  
C. L. Headley
Keyword(s):  
Cell Wall ◽  
Early Stage ◽  
Nuclear Material ◽  
Spore Coat ◽  
Clostridium Sporogenes ◽  
Thin Sections ◽  
Young Cell ◽  
The Core ◽  
Resting Spore ◽  
Peripheral Areas

The process by which dormant spores of Clostridium sporogenes are transformed into vegetative cells has been studied in thin sections with the electron microscope. The resting spore appears very similar to that of other Bacillaceae for it possesses a rather featureless core which is surrounded by a core membrane, cortex, and spore coat(s); beyond lies a sac-like exosporium. At an early stage in germination the core becomes differentiated into peripheral areas of nuclear material and a ribosome-packed cytoplasm; a germ cell wall develops beyond the core membrane. The later stages of germination coincide with the beginning of outgrowth: the cortex disintegrates into a sponge-like mass of fibrils, and the young cell grows while still retained within the unbroken spore coats. The young cell now has a fibrillar nucleoplasm, a ribosome-rich cytoplasm, an occasional mesosome, a plasma membrane, and a relatively thick cell wall. Subsequently, the cortex vanishes completely, and the new vegetative cell elongates and finally emerges terminally through the spore coats and the exosporium. The exosporium of C. sporogenes consists of two layers: a thick inner one which is laminated, and a thin outer one possessing a fringe of hair-like projections.

scholarly journals Localization of the Cortex Lytic Enzyme CwlJ in Spores of Bacillus subtilis

2002 ◽  
Vol 184 (4) ◽  
pp. 1219-1224 ◽  
Author(s):  
Irina Bagyan ◽  
Peter Setlow
Keyword(s):  
Bacillus Subtilis ◽  
Spore Germination ◽  
Dipicolinic Acid ◽  
High Salt ◽  
Lytic Enzyme ◽  
Spore Coat ◽  
Coat Proteins ◽  
His Tag ◽  
Spore Coat Proteins ◽  
Triton X

ABSTRACT The enzyme CwlJ is involved in the depolymerization of cortex peptidoglycan during germination of spores of Bacillus subtilis. CwlJ with a C-terminal His tag was functional and was extracted from spores by procedures that remove spore coat proteins. However, this CwlJ was not extracted from disrupted spores by dilute buffer, high salt concentrations, Triton X-100, Ca2+-dipicolinic acid, dithiothreitol, or peptidoglycan digestion, disappeared during spore germination, and was not present in cotE spores in which the spore coat is aberrant. These findings indicate the following: (i) the reason decoated and cotE spores germinate poorly with dipicolinic acid is the absence of CwlJ from these spores; and (ii) CwlJ is located in the spore coat, presumably tightly associated with one or more other coat proteins.

scholarly journals gerT, a Newly Discovered Germination Gene under the Control of the Sporulation Transcription Factor σK in Bacillus subtilis

2007 ◽  
Vol 189 (21) ◽  
pp. 7681-7689 ◽  
Author(s):  
Caitlin C. Ferguson ◽  
Amy H. Camp ◽  
Richard Losick
Keyword(s):  
Transcription Factor ◽  
Bacillus Subtilis ◽  
Gene Product ◽  
Early Stage ◽  
Dna Binding Protein ◽  
Positive Control ◽  
Negative Control ◽  
Spore Coat ◽  
Morphogenetic Protein ◽  
Two Stages

ABSTRACT We report the identification of a gene, herein designated gerT (formerly yozR), that is involved in germination by spores of Bacillus subtilis. The gerT gene is induced late in sporulation under the positive control of the transcription factor σK and under the negative control of the DNA-binding protein GerE. The gerT gene product (GerT) is a component of the spore coat, and its incorporation into the coat takes place in two stages. GerT initially assembles into foci, which then spread around the developing spore in a process that is dependent on the morphogenetic protein CotE. Mutant spores lacking GerT respond poorly to multiple germinants and are impaired at an early stage of germination.

Three-dimensional analysis of morphogenesis induced by mating pheromone alpha factor in Saccharomyces cerevisiae

1989 ◽  
Vol 94 (2) ◽  
pp. 207-216
Author(s):  
M. Baba ◽  
N. Baba ◽  
Y. Ohsumi ◽  
K. Kanaya ◽  
M. Osumi
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Dimensional Analysis ◽  
Early Stage ◽  
Morphological Changes ◽  
Three Dimensional ◽  
Membrane Vesicles ◽  
Fixation Method ◽  
Thin Sections ◽  
Alpha Factor ◽  
Intracellular Organelles

Ultrastructural analyses of cytoplasmic changes in Saccharomyces cerevisiae X2180-1A (MATa) that had been treated with alpha factor were performed by using the freeze-substitution fixation method. After alpha factor treatment, cells exhibited a pointed projection, which is a unique pattern of oriented cell surface growth. The relationship between projection formation and intracellular organelles was examined using serial thin sections and computer-aided three-dimensional reconstructions. Using these analyses membrane vesicles and other organelles were detected, and studies on their dynamic structural reorganization became feasible. Production of membrane vesicles (average 65 nm in diameter) was induced upon exposure of the cells to alpha factor before projection emergence. The total number of membrane vesicles increased at the early stage and decreased at the late stage of projection formation. Three-dimensional analysis indicated that the vesicles were at first dispersed throughout the cell, then accumulated at the site where the projection formed. Morphological changes and multiplication of the Golgi body were seen during the process of projection formation. Other intracellular organelles (nucleus, vacuole, rough endoplasmic reticulum and mitochondria) were also rearranged, showing a polar organization of the cytoplasm during projection formation.

scholarly journals THE COMPOSITION AND STRUCTURE OF BACTERIAL SPORES

1963 ◽  
Vol 16 (3) ◽  
pp. 579-592 ◽  
Author(s):  
A. D. Warth ◽  
D. F. Ohye ◽  
W. G. Murrell
Keyword(s):  
Electron Microscopy ◽  
Cell Wall ◽  
Heat Resistance ◽  
Dipicolinic Acid ◽  
Diaminopimelic Acid ◽  
Bacterial Spores ◽  
Bacillus Species ◽  
Thin Sections ◽  
Composition And Structure ◽  
Soluble Fractions

The composition of the insoluble "integuments" and soluble "contents" fractions of spores of four Bacillus species of widely differing heat resistance were compared. Electron microscopy of thin sections was also used to determine and compare the morphological structures in the integument preparations. The soluble fractions of the thermophiles, B. coagulans and B. stearothermophilus, had a higher content of hexose and dipicolinic acid. The hexose content of both fractions of the four species was related to heat resistance. Integument fractions consisted chiefly of protein together with variable amounts of the mucopeptide constituents, α, ϵ-diaminopimelic acid (DAP) and hexosamine. In the thermophiles the DAP and hexosamine were found chiefly in the insoluble integuments fractions, while in B. cereus and B. subtilis most of this material was soluble. Integument preparations, containing mainly protein with little mucopeptide, consisted chiefly of outer and inner spore coats, while preparations having more mucopeptide contained also residual cortical material and a cortical membrane (possibly the germ cell wall). The results suggest that spore integuments consist of mainly proteinaceous outer and inner coats together with variable amounts of residual cortex and cortical membrane which contain the mucopeptide material.

scholarly journals Morphogenetic Proteins SpoVID and SafA Form a Complex during Assembly of the Bacillus subtilis Spore Coat

2000 ◽  
Vol 182 (7) ◽  
pp. 1828-1833 ◽  
Author(s):  
Amanda J. Ozin ◽  
Adriano O. Henriques ◽  
Hong Yi ◽  
Charles P. Moran
Keyword(s):  
Bacillus Subtilis ◽  
Modular Design ◽  
Early Stage ◽  
Multilayered Structure ◽  
Terminal Region ◽  
Immunogold Electron Microscopy ◽  
Spore Coat ◽  
Coat Proteins ◽  
Bacillus Subtilis Spore ◽  
Cell Extracts

ABSTRACT During endospore formation in Bacillus subtilis, over two dozen polypeptides are assembled into a multilayered structure known as the spore coat, which protects the cortex peptidoglycan (PG) and permits efficient germination. In the initial stages of coat assembly a protein known as CotE forms a ring around the forespore. A second morphogenetic protein, SpoVID, is required for maintenance of the CotE ring during the later stages, when most of proteins are assembled into the coat. Here, we report on a protein that appears to associate with SpoVID during the early stage of coat assembly. This protein, which we call SafA for SpoVID-associated factor A, is encoded by a locus previously known as yrbA. We confirmed the results of a previous study that showed safA mutant spores have defective coats which are missing several proteins. We have extended these studies with the finding that SafA and SpoVID were coimmunoprecipitated by anti-SafA or anti-SpoVID antiserum from whole-cell extracts 3 and 4 h after the onset of sporulation. Therefore, SafA may associate with SpoVID during the early stage of coat assembly. We used immunogold electron microscopy to localize SafA and found it in the cortex, near the interface with the coat in mature spores. SafA appears to have a modular design. The C-terminal region of SafA is similar to those of several inner spore coat proteins. The N-terminal region contains a sequence that is conserved among proteins that associate with the cell wall. This motif in the N-terminal region may target SafA to the PG-containing regions of the developing spore.

scholarly journals Identification of a New Gene Essential for Germinationof Bacillus subtilis Spores withCa2+-Dipicolinate

2003 ◽  
Vol 185 (7) ◽  
pp. 2315-2329 ◽  
Author(s):  
Katerina Ragkousi ◽  
Patrick Eichenberger ◽  
Christiaan van Ooij ◽  
Peter Setlow
Keyword(s):  
Bacillus Subtilis ◽  
Spore Germination ◽  
Function Analysis ◽  
Dipicolinic Acid ◽  
Functional Characterization ◽  
Lytic Enzyme ◽  
Spore Coat ◽  
Gene Encoding ◽  
Reading Frame ◽  
Genes Encoding

ABSTRACT Bacillus subtilis spores can germinate with a 1:1 chelate of Ca2+ and dipicolinic acid (DPA), a compound present at high levels in the spore core. Using a genetic screen to identify genes encoding proteins that are specifically involved in spore germination by Ca2+-DPA, three mutations were identified. One was in the gene encoding the cortex lytic enzyme, CwlJ, that was previously shown to be essential for spore germination by Ca2+-DPA. The other two were mapped to an open reading frame, ywdL, encoding a protein of unknown function. Analysis of ywdL expression showed that the gene is expressed during sporulation in the mother cell compartment of the sporulating cell and that its transcription is σE dependent. Functional characterization of YwdL demonstrated that it is a new spore coat protein that is essential for the presence of CwlJ in the spore coat. Assembly of YwdL itself into the spore coat is dependent on the coat morphogenetic proteins CotE and SpoIVA. However, other than lacking CwlJ, ywdL spores have no obvious defect in their spore coat. Because of the role for YwdL in a part of the spore germination process, we propose renaming ywdL as a spore germination gene, gerQ.

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