Ultrastructural, physiological, and cytochemical characterization of cores in group D streptococci

Coleman, Sylvia E.; Bleiweis, Arnold S.

doi:10.1128/jb.129.1.445-456.1977

Cited by 9 publications

(3 citation statements)

References 25 publications

(12 reference statements)

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“…A tubule seen in group D streptococcal L-forms which extended beyond the cell is probably cell wall material (23). Cores, which are tubules postulated to be of membranous origin, were also seen in group D streptococci (22).…”

Section: Figmentioning

confidence: 96%

Do prokaryotes contain microtubules?

Bermudes¹,

Hinkle²,

Margulis³

1994

Microbiological Reviews

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Proteus mirabilis Vibrio mannus Vibrio psychroerythrus Chondromyces crocatus Myxococcus xanthus Anabaena sp. strains B-380 and B-381 Anabaena sp. strain B-378 Anabaena sp. strain 1448 Anabaena aequalis Anabaena catenula Anabaena cylindrica B-629, B381, and Wolk Anabaena minutissima Anabaena variabilis Calothrix sp. strain UTEX B1827 Calothrix sp. strain Cambridge 1410/6 Calothrix anomala Calothrix brevissima Calothrix javanica Calothrix marchica Calothrix membranacea Calothrix parientina Calothrix pulvinata Calothrix scopulonium Fremyella diplosiphon Gloeotrichia sp. strain UTEX

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Section: Figmentioning

confidence: 96%

Do prokaryotes contain microtubules?

Bermudes¹,

Hinkle²,

Margulis³

1994

Microbiological Reviews

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“…Material with a membranous appearance is shedding from the cell surface (arrowheads). 3. A single cell initiating septum formation (S) which incorporates an outer matrix layer (M).…”

Section: Resultsmentioning

confidence: 99%

Life Cycles in the Methanogenic Archaebacterium Methanosarcina mazei

Robinson

1986

Appl Environ Microbiol

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Methanosarcina mazei S6 and LYC were used to study the structure and differentiation of the aggregating methanogens. Cultures harvested under various conditions are described at the ultrastructural level. Cells of strain S6 are enclosed by a layer 12 nm thick in contact with the plasma membrane. In sarcinal colonies, cells are held in close association by a fibrous matrix up to 60 nm thick. Colony maturation was examined in strain S6 over a period of 1 year. Changes occurred in the shape and staining of individual cells. Also, various inclusion bodies were observed that either persist throughout colony maturation or are only found at certain growth stages. Two types of cores that are composed of double membranes in M. mazei S6 are described. One has a 90-nm diameter and contains electron-dense granules similar to those found in the cytoplasm. The other core type does not contain granules, is more numerous, and is found in older cultures. Two life cycles are described for M. mazei based on electron microscope examinations. A complex life cycle involving the release of single cells is described with two variations for strains S6 and LYC. When released cells of strain S6 are placed in fresh medium they can repeat the cycle. In addition, a limited cycle is described for both strains of M. mazei. This limited cycle contains the only sarcinal morphotypes observed in M. barkeri. When M. mazei S6 remains in the limited cycle and does not disaggregate in stationary phase, several types of possible resting forms are found.

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“…Only few reports have shown the presence of microtubular structures (4, 6, 8), and membrane structures (7,9) in the L-forms.Cores are large, hollow, straight rod-shaped structures found in the cytoplasm of bacteria that were first observed by Abrams et al (1) in 1964. Thereafter, these structures in bacteria have been found almost exclusively in group D streptococci (5,11,12). In the L-forms or protoplasts, cores or core-like structures have been demonstrated in group D streptococcal protoplasts by Abrams et al (1) and Cohen et al (3), and in L-forms of Pseudomonas aeruginosa by Hubert et al (10).…”

mentioning

confidence: 97%

Core‐like and Microtubular Structures in a Stable L‐form of Escherichia coli

Eda

Kanda

Mori

et al. 1979

Microbiology and Immunology

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Although there have been a number of ultrastructural studies on the L-forms induced from various bacterial species, little is known about the presence of intracellular membranous structures in these organisms (2, 4). According to the reports concerning ultrastructures of the L-forms, the L-forms consist of various sizes of cells, and the L-form cells lack a cell wall and have nuclear materials and dispersed ribosomes in the cytoplasm. In general, it is said that intracellular membranous structures seem to be difficult to find in the L-forms and, if they are found, they are observed most frequently in the L-forms induced from gram-positive cocci (4). Only few reports have shown the presence of microtubular structures (4,6,8), and membrane structures (7, 9) in the L-forms.Cores are large, hollow, straight rod-shaped structures found in the cytoplasm of bacteria that were first observed by Abrams et al (1) in 1964. Thereafter, these structures in bacteria have been found almost exclusively in group D streptococci (5,11,12). In the L-forms or protoplasts, cores or core-like structures have been demonstrated in group D streptococcal protoplasts by Abrams et al (1) and Cohen et al (3), and in L-forms of Pseudomonas aeruginosa by Hubert et al (10). There have been no reports concerning cores in L-forms of Escherichia coli.We have already reported on intracellular membrane structures observed in the L-forms induced from Staphylococcus aureus (8), Escherichia coli (7), and Proteus mirabilis (9), and in this paper we demonstrate core-like and microtubular structures found in a stable L-form of Escherichia coli by electron microscopy.An L-form of Escherichia coli strain EcL (7) used was subcultured and maintained in L-form broth composed of 3.7% brain heart infusion broth (Difco), 0.5% yeast extract (Difco), 4% NaCl, and 10% horse serum (Bio Test) for several years. The L-form is stable in the absence of antibiotics and has been maintained for several years without any evidence of reversion during routine laboratory manipulations. This strain reached maximum growth at 24 hr in the L-form broth.The L-form, which was cultured at 37 C for 24 hr in the L-form broth, was harvested by centrifugation at 10,000 g for 30 min (Sorvall RC-2B) at 4 C. Sediments were prefixed for 2 hr at 4 C with chilled 2% glutaraldehyde in 0.1 M cacodylate buffer (pH 7.2) and were then harvested by centrifugation. The fixed cells were washed four times with the same buffer in the cold, followed by postfixation with 1% osmium tetroxide in 0.1 M cacodylate buffer (pH 7.4) for 2 hr at 4 C. After dehydration in a graded acetone series, specimens were embedded in Epon 812 . Ultrathin sections were obtained with a Reichert OM U2 ultramicrotome and stained with 2% uranyl acetate and Reynolds lead citrate. Preparations were examined and photographed with a Hitachi HU-12 AS electron microscope at 75 kV acceleration.The E. coli L-form strain EcL consisted of a number of large and small cells measuring 250 nm to 3 pm in size. Each of the cells was spherical i...

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Ultrastructural, physiological, and cytochemical characterization of cores in group D streptococci

Cited by 9 publications

References 25 publications

Do prokaryotes contain microtubules?

Do prokaryotes contain microtubules?

Life Cycles in the Methanogenic Archaebacterium Methanosarcina mazei

Core‐like and Microtubular Structures in a Stable L‐form of Escherichia coli

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