The role of multivalent cations in the organization and structure of bacterial cell walls

SUMMARYQuantitative absorption of antisera was used to study the effect of calcium on the antigenic surface of Rhizobium trifolii. Antisera to Ca-deficient and Ca-adequate rhizobia (whole or broken) revealed two parts in the absorption curve : range I in which there was ready removal of most of the agglutinating antibody with a very small absorbing dose; range 2 in which the remaining agglutinating antibody resisted absorption. When Ca-adequate bacteria were used for absorption, range I consisted of about 87% of the total titre. The corresponding figure with Ca-deficient bacteria was 95 %. These values have been attributed to three types of antibody; avid I (readily absorbed by either kind of bacterium), avid 2

Section: The Efect Of Heat and Mereaptoethanol (Me) On Antiseramentioning

confidence: 74%

Modification of the Antigenic Surface of Rhizobium trifolii by a Deficiency of Calcium

Vincent

Humphrey

1968

“…Descending paper chromatography was done on Whatman no. I paper, usually using the solvent systems I, 11, I11 and IVY detecting spots with alkaline AgN03, aniline hydrogen phthalate and periodate-SchWs reagents (Baddiley, Buchanan, Handschumacher & Prescott, 1956 (Edward & Waldron, 1952) were used. When necessary sugars were eluted from chromatograms and their identities confirmed by further tests.…”

Section: )-mentioning

confidence: 99%

“…A correlation has been found between bactericidal activity and chelate stability constants for polyaminocarboxylic acids related to EDTA, which indicated that chelation was involved in the toxic action of these compounds (Gray & Wilkinson, 19654. The structural importance of multivalent metal cations in the wall of P. aeruginosa has been confirmed (Eagon & Carson, 1965;Asbell & Eagon, 1966a, b). Treatmh of the bacteria with EDTA caused these cations to become soluble (Eagon & Carson, 1965) and also of the lipopolysaccharide component of the cell wall (Gray & Wilkinson, 1965 b).…”

Section: Introductionmentioning

confidence: 99%

Studies on the Cell Walls of Pseudomonas Species Resistant to Ethylenediaminetetra-acetic Acid

Wilkinson

1968

S U M M A R YCell walls were prepared from various species of the genus Pseudomonas which are resistant to ethylenediaminetetra-acetic acid (EDTA). The cell walls were analysed and comparisons made with the walls of EDTA-sensitive pseudomonads. The walls had none of the structural features which appeared to characterize EDTA-sensitive pseudomonads. Lipopolysaccharide was not extracted from the walls of resistant organisms by EDTA at pH 9-2. The wall of P . iodinum contained almost no lipid or protein but consisted mainly of glycosaminopeptide and material which resembled a teichoic acid. It is proposed that this organism be removed from the genus Pseudomonas. The walls of P. diminuta, P. maltophilia, P. pavonacea and P. rubescens had compositions broadly characteristic of Gram-negative bacteria. The four species are not obviously related. Glycolipids were present in the walls of P. diminuta, P. maltophilia and P. rubescens. An ornithine-containing lipid was isolated from P. rubescens and partly characterized. A small amount of this lipid was also present in P. maltophilia. The wall of P. maltophilia was distinctive in its wide range of monosaccharide components, including an unidentified neutral sugar of high mobility on paper chromatograms. INTRODUCTIONEthylenediaminetetra-acetic acid (EDTA) has a toxic effect on Pseudomonas aeruginosa (MacGregor & Elliker, 1958; Gray & Wilkinson, 1965a;Eagon & Carson, 1965;Wilkinson, 1967), apparently the result of a lytic action by it on the cell wall of the organism (Gray & Wilkinson, 1965a, b ;Eagon & Carson, 1965). A correlation has been found between bactericidal activity and chelate stability constants for polyaminocarboxylic acids related to EDTA, which indicated that chelation was involved in the toxic action of these compounds (Gray & Wilkinson, 19654. The structural importance of multivalent metal cations in the wall of P. aeruginosa has been confirmed (Eagon & Carson, 1965;Asbell & Eagon, 1966a, b). Treatmh of the bacteria with EDTA caused these cations to become soluble (Eagon & Carson, 1965) and also of the lipopolysaccharide component of the cell wall (Gray & Wilkinson, 1965 b). Although EDTA has been found to extract lipopolysaccharide from Escherichia coli, the bacteria remained viable under the conditions used (Leive, 1965). Except when used in conjunction with organic cations (Wolin, 1966;Goldschmidt & Wyss, 1967;Voss, 1967), EDTA does not seem to be highly toxic for Gram-negative bacteria other than pseudomonads (Gray & Wilkinson, 1965 a;Wilkinson, 1967). This hypersensitivity to EDTA might prove to be a useful characteristic in the taxonomy of the pseudomonads (Shively & Hartsell, 1964;Wilkinson, 1967 S . G. W I L K I N S O NIn a survey of various pseudomonads (Wilkinson, 1967), only strains of the following species were found to be resistant to EDTA: Pseudomonas diminuta, P. geniculata, P. iodinum, P. maltophilia, P. pavonacea, P. rubescens. The inclusion of these organisms in the genus Pseudomonas has been considered doubtful by other workers who used di...

“…However, as the same preparation technique was used throughout, these observed differences must reflect some change in the wall structure or composition. Mg2+ deficiency in Gram-negative bacteria, induced either by growth in a Mg2+-free medium or by addition of EDTA, is known to cause permeability changes (Brock, 1962) and weakened bacterial cell walls (Asbell & Eagon, 1966). The more wavy wall during Mg2+ starvation might then result from shrinkage during the dehydration process when the wall is not stabilized to the same extent as in the presence of Mg2+ ions.…”

Section: A B O V a L L I U Smentioning

confidence: 99%

Morphological and Chemical Characteristics of a Cytophaga sp. Grown under Conditions of Magnesium Excess and Magnesium Limitation

Bovallius¹

1979

Cytophaga sp. NCMB 13 14 produces, especially under Mg2+-limited growth conditions, a factor that liberates a cholinesterase from plaice muscle. Just after the onset of Mg2+ limitation in a batch culture, there is a period of rapid production of the factor. Changes also occur in the morphology, ATP content and gross chemical composition of the bacteria.The protein and carbohydrate contents are raised by 60 % and 100 %, respectively, while the RNA and ATP contents are reduced to 70% and 40% of the original values. Increased amounts of carbohydrate found outside the cells after Mg2+ limitation at least partly correlated with extracellular slime observed in electron micrographs.