Sporulation in <i>Bacillus subtilis</i>. Morphological changes

Kay, D.; Warren, S. C.

doi:10.1042/bj1090819

Cited by 76 publications

(49 citation statements)

References 17 publications

(16 reference statements)

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“…Smaller intracellular offspring (Ͻ1 m in cross-sectional diameter) contained an electron-dense core, however most large offspring possessed cores with a mottled, lighter appearance. The electron-dense granular appearance of a spore core can be indicative of an immature or germinated spore, while mature endospore cores often have a poor affinity for stains and are more electron lucent (27,51). The nature of the white granular structures within the core is difficult to determine.…”

Section: Discussionmentioning

confidence: 99%

Nocturnal Production of Endospores in Natural Populations ofEpulopiscium-Like Surgeonfish Symbionts

et al. 2005

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Prior studies have described a morphologically diverse group of intestinal microorganisms associated with surgeonfish. Despite their diversity of form, 16S rRNA gene surveys and fluorescent in situ hybridizations indicate that these bacteria are low-G؉C gram-positive bacteria related to Epulopiscium spp. Many of these bacteria exhibit an unusual mode of reproduction, developing multiple offspring intracellularly. Previous reports have suggested that some Epulopiscium-like symbionts produce dormant or phase-bright intracellular offspring. Close relatives of Epulopiscium, such as Metabacterium polyspora and Clostridium lentocellum, are endospore-forming bacteria, which raises the possibility that the phase-bright offspring are endospores. Structural evidence and the presence of dipicolinic acid demonstrate that phase-bright offspring of Epulopiscium-like bacteria are true endospores. In addition, endospores are formed as part of the normal daily life cycle of these bacteria. In the populations studied, mature endospores were seen only at night and the majority of cells in a given population produced one or two endospores per mother cell. Phylogenetic analyses confirmed the close relationship between the endospore-forming surgeonfish symbionts characterized here and previously described Epulopiscium spp. The broad distribution of endospore formation among the Epulopiscium phylogenetic group raises the possibility that sporulation is a characteristic of the group. We speculate that spore formation in Epulopiscium-like symbionts may be important for dispersal and may also enhance survival in the changing conditions of the fish intestinal tract.

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Section: Discussionmentioning

confidence: 99%

Nocturnal Production of Endospores in Natural Populations ofEpulopiscium-Like Surgeonfish Symbionts

et al. 2005

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“…The sequential nature of the cytological changes which occur during sporulation of bacilli has been demonstrated in Bacillus cereus (Young & Fitz-James 1959a, b ;Fitz-James, 1965) and in Bacillus subtilis (Schaeffer, Ionesco, Ryter & Balassa, 1965: Szulmajster, 1964Ryter, 1965;Kay & Warren, 1968). In the latter organisms Schaeffer et al (1965) described eight stages of development (Fig.…”

Section: Introductionmentioning

confidence: 99%

Sporulation in Bacillus subtilis. Establishment of a Time Scale for the Morphological Events

Dawes

Kay

Mandelstam

1969

Journal of General Microbiology

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S U M M A R YChemostat cultures of Bacillus subtilis can be obtained in which a large proportion of the cells are initiated to sporulation. In a steady-state culture the fraction of cells which exhibit any particular stage of spore development is a function of the time taken for a cell to reach that stage after having been initiated to spore formation, and oft he time required for the cell to pass through that stage. Equations describing this relationship have been derived. From these equations and from values for the fractions of cells exhibiting the morphological stages of spore development seen in electron micrographs, a time scale for the morphological events occurring during sporulation has been constructed.By observing the effect of a sudden decrease in flow rate of a continuous flow system initially at steady state it was possible to time the occurrence of specific events, biochemical or physical, which were connected with the formation of spores. By this means, refractility was shown to be associated with stage V.

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“…Formation of heat-resistant spores from vegetative cells of B. subtilis takes about 7 h at 37°C. The morphological changes during sporulation were initially characterized by electron microscopy (145,251). The basic sequence of changes is similar for all species of Bacillus and Clostridium that have been studied (79) and is illustrated in Fig.…”

Section: Morphpological Stages Of Sporulationmentioning

confidence: 99%

Compartmentalization of Gene Expression duringBacillus subtilisSpore Formation

Hilbert

Piggot

2004

Microbiol Mol Biol Rev

318

432

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Gene expression in members of the family Bacillaceae becomes compartmentalized after the distinctive, asymmetrically located sporulation division. It involves complete compartmentalization of the activities of sporulation-specific sigma factors, σF in the prespore and then σE in the mother cell, and then later, following engulfment, σG in the prespore and then σK in the mother cell. The coupling of the activation of σF to septation and σG to engulfment is clear; the mechanisms are not. The σ factors provide the bare framework of compartment-specific gene expression. Within each σ regulon are several temporal classes of genes, and for key regulators, timing is critical. There are also complex intercompartmental regulatory signals. The determinants for σF regulation are assembled before septation, but activation follows septation. Reversal of the anti-σF activity of SpoIIAB is critical. Only the origin-proximal 30% of a chromosome is present in the prespore when first formed; it takes ≈15 min for the rest to be transferred. This transient genetic asymmetry is important for prespore-specific σF activation. Activation of σE requires σF activity and occurs by cleavage of a prosequence. It must occur rapidly to prevent the formation of a second septum. σG is formed only in the prespore. SpoIIAB can block σG activity, but SpoIIAB control does not explain why σG is activated only after engulfment. There is mother cell-specific excision of an insertion element in sigK and σE-directed transcription of sigK, which encodes pro-σK. Activation requires removal of the prosequence following a σG-directed signal from the prespore

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Sporulation in Bacillus subtilis. Morphological changes

Cited by 76 publications

References 17 publications

Nocturnal Production of Endospores in Natural Populations ofEpulopiscium-Like Surgeonfish Symbionts

Nocturnal Production of Endospores in Natural Populations ofEpulopiscium-Like Surgeonfish Symbionts

Sporulation in Bacillus subtilis. Establishment of a Time Scale for the Morphological Events

Compartmentalization of Gene Expression duringBacillus subtilisSpore Formation

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