Separation and Localization of Cell Wall Layers of a Gram-Negative Bacterium

Forsberg, Cecil W.; Costerton, J. W.; MacLeod, Robert A.

doi:10.1128/jb.104.3.1338-1353.1970

Cited by 92 publications

(84 citation statements)

References 33 publications

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“…This strain was originally isolated from a marine clam and has been classified as a Pseudomonas sp. type IV (Forsberg et al, 1970). It was grown at 25°C in a liquid medium containing 0.8% nutrient broth (bioMerieux 51101), 0.5% yeast extract (Difco 012701) in a salt solution consisting of 0.22 M NaC1, 0.026 M MgCl,, and 0.1 mM FeS04(NH,),S04~6H,0.…”

Section: Bacterial Strains and Mediamentioning

confidence: 99%

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Role of envelopes of gram‐negative bacteria in cadmium binding and toxicity

Bauda¹,

Block²

1990

Environ. Toxicol. Water Qual.

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Whole cells, mureinoplasts, and protoplasts of gram-negative bacteria were used in cadmium biosorption and toxicity determinations. It was shown that whole cells of Pseudomom fluorescens bind less metal than other bacterial forms, suggesting the outer membrane acts as a barrier toward metals. Such a role was confirmed by toxicity measurements showing a lower toxic effect of cadmium in the presence of the outer membrane. Chemically modified bacteria, with carboxyl groups masked, were used to identify the cadmium binding sites. Results indicate that care is necessary in interpretation since the acid pH used in the blockage reaction was shown to interfere with the cadmium binding. Moreover, the blockage reagents have been shown to modify the cadmium toxicity.

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Section: Bacterial Strains and Mediamentioning

confidence: 99%

“…haloplanktis and P . fluorescens were prepared as described by Forsberg et al (1970). Stationary phase bacteria were harvested by centrifugation at 16,300 x g for 20 min at 4°C.…”

Section: Mureinoplast and Protoplast Preparationmentioning

confidence: 99%

Role of envelopes of gram‐negative bacteria in cadmium binding and toxicity

Bauda¹,

Block²

1990

Environ. Toxicol. Water Qual.

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“…Stained sections of marine pseudomonad B-16 (ATCC 19855) reveal that the cell envelope of this organism has a structure typical of other gram-negative bacteria (9). Since inorganic ions are required to maintain the cell envelope intact (2), control of the salt composition of the medium used to suspend the cells has led to a method for the separation of the various layers of the cell envelope of this organism (9). These studies have revealed that, in addition to the inner and outer membranous structures and the periplasmic space observed in stained thin sections, there is a layer which lies on the surface of the cell outside of the outer membrane structure.…”

Section: Thompson and Macleodmentioning

confidence: 99%

“…There is also a peptidoglycan layer closely apposed to the surface of the cytoplasmic membrane which is ordinarily not detectable in stained thin sections of cells of this organism (11), although such a layer is readily detectable in some other species of gram-negative bacteria (12). Thus, four cell wall layers lying outside of the cytoplasmic membrane of this organism have been detected (9). Since the methods used permit the separation of these layers from the cell and from each other, advantage has been taken of this fact to determine the location of alkaline phosphatase in the cell wall of this organism MATERIALS AND METHODS Organism, medium, growth, and harvesting of cells.…”

Section: Thompson and Macleodmentioning

confidence: 99%

“…Cells, after being washed three times in 0.5 M NaCl and suspended in 0.5 M sucrose for 30 min, were harvested by centrifugation. The mureinoplasts formed (cells with the outer three layers of the cell wall removed [9]) were suspended to a concentration equivalent to 6 mg (dry weight) of cells per ml in a protoplasting medium containing 150 ug of lysozyme per ml of complete salts solution made 0.01 M with respect to tris(hydroxymethyl)aminomethane buffer, pH 7.5.…”

Section: Thompson and Macleodmentioning

confidence: 99%

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Biochemical Localization of Alkaline Phosphatase in the Cell Wall of a Marine Pseudomonad

Thompson

MacLeod

1974

J Bacteriol

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The various layers of the cell envelope of marine pseudomonad B-16 (ATCC 19855) have been separated from the cells and assayed directly for alkaline phosphatase activity under conditions established previously to be optimum for maintenance of the activity of the enzyme. Under conditions known to lead to the release of the contents of the periplasmic space from the cells, over 90% of the alkaline phosphatase was released into the medium. Neither the loosely bound outer layer nor the outer double-track layer (cell wall membrane) showed significant activity. A small amount of the alkaline phosphatase activity of the cells remained associated with the mureinoplasts when the outer layers of the cell wall were removed. Upon treatment of the mureinoplasts with lysozyme, some alkaline phosphatase was released into the medium and some remained with the protoplasts formed. Cells washed and suspended in 0.5 M NaCl were lysed by treatment with 2% toluene, and 95% of the alkaline phosphatase in the cells was released into the medium. Cells washed and suspended in complete salts solution (0.3 M NaCl, 0.05 M MgSO,, and 0.01 M KCl) or 0.05 M MgSO4 appeared intact after treatment with toluene but lost 50 and 10%, respectively, of their alkaline phosphatase. The results suggest that the presence of Mg2" in the cell wall is necessary to prevent disruption of the cells by toluene and may also be required to prevent the release of alkaline phosphatase by toluene when disruption of the cells by toluene does not take place.There are a group of degradative enzymes in gram-negative bacteria which lie external to the cytoplasmic membrane of the cell (13). The biochemical evidence for this conclusion though indirect is convincing. The activity of the enzymes can be measured by using intact cells even though the substrate is unable to penetrate the cytoplasmic membrane (1). The enzymes can be released from the cells by osmotic shock (22), spheroplast formation (17), or a wash with 0.2 M MgCl2 (3), procedures which do not solubilize enzymes in the cytoplasm. The exact location of the enzymes in the bacterial envelope is less clear. There are, however, several reasons for believing that a barrier exists between the enzymes and the outside surface of the cell. The activity of the enzymes for most substrates is lower when associated with the cells than after release into the suspending medium (1). Many enzymes which are wall associated in gram negative bacteria are excreted into the medium by gram-positive bacteria. Alkaline phosphatase, one of the wallassociated enzymes is lost into the medium by a mutant strain of Escherichia coli with defective cell walls (18). Stained thin sections of gramnegative bacteria reveal two membranous structures, an inner membrane which is the cytoplasmic membrane and an outer membrane, referred to as the cell wall membrane. Since these membranes are separated by an electron transparent region called the periplasmic space, it has been concluded that the wall-associated enzymes are probably located in the periplasm...

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Pseudoalteromonas

Bowman¹,

McMeekin²

2015

Bergey's Manual of Systematics of Archaea and Bacteria

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Pseu.do.al.te.ro.mo' nas . Gr. adj. pseudes false; M.L. n. Alteromonas the genus Alteromonas ; M.L. n. Pseudoalteromonas false Alteromonas . Proteobacteria / Gammaproteobacteria / Alteromonadales / Alteromonadaceae / Pseudoalteromonas Straight rods , approximately 1 × 2–3 µm, occurring singly or in pairs. Do not form spores or cysts. Do not accumulate poly‐β‐hydroxybutyrate. Nonbioluminescent. Gram negative. Motile by means of a single polar flagellum , either unsheathed or sheathed. Colonies are nonpigmented or pigmented. Chemoheterotrophic. Aerobic, possessing a strictly respiratory type of metabolism with oxygen as the terminal electron acceptor. No growth occurs anaerobically. A constitutive arginine dihydrolase system is usually absent. One species ( P. denitrificans ) is able to denitrify. Utilize a range of carbon substrates, including carbohydrates, alcohols, organic acids, and amino acids. Form gelatinase and lipase. Ammonia serves as a nitrogen source. Amino acids may be required by some strains for growth. Requires Na + ions for growth . Mostly psychrotolerant, with growth occurring between 0 and 40°C. Several species produce autotoxic antibiotic compounds. Isolated from seawater, sediment, sea ice, surfaces of stones, marine algae, marine invertebrates, and salted foods. The major quinone is ubiquinone‐8 (Q‐8). Major fatty acids are C 16:0 , C 16:1 ω7c , C 17:1 ω8c , and C 18:1 ω7c . Member of the order Alteromonadales , family Alteromonadaceae , in the Gammaproteobacteria . The mol % G + C of the DNA is : 38–48 ( T m ). Type species : Pseudoalteromonas haloplanktis (Zobell and Upham 1944) Gauthier, Gauthier and Christen 1995a, 759 ( Alteromonas haloplanktis (Zobell and Upham 1944) Reichelt and Baumann 1973a, 438; “ Vibrio haloplanktis ” Zobell and Upham 1944, 261.)

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Separation and Localization of Cell Wall Layers of a Gram-Negative Bacterium

Cited by 92 publications

References 33 publications

Role of envelopes of gram‐negative bacteria in cadmium binding and toxicity

Role of envelopes of gram‐negative bacteria in cadmium binding and toxicity

Biochemical Localization of Alkaline Phosphatase in the Cell Wall of a Marine Pseudomonad

Pseudoalteromonas

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