Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “cell wall composition”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 109 records · Page 6Linked to original sources

Effects of calcium and kinetin on growth and cell wall composition of pea epicotyls.

Kinetin and CaCl(2), in the presence of indoleacetic acid, promoted lateral expansion of epicotyls of decapitated and derooted Alaska pea seedlings (Pisum sativum L.) and inhibited their elongation. This growth response was correlated with the development of cell walls unusually rich in pectic uronic acids. Epicotyls in calcium-auxin solutions continued to enlarge and to add new wall material long after tissues in auxin only had stopped. Longitudinal enlargement, associated with the development of walls poor in pectic uronic acids, was favored by KCl, MgCl(2), and ethylenediaminetetraacetate. The last of these agents promoted the loss of (45)Ca from the epicotyls. Seedings grown in vermiculite moistened with CaCl(2), KCl, or MgCl(2) solutions did not differ in appearance or in the composition of their walls. They responded similarly to experimental treatment except that the decapitated epicotyls of the MgCl(2)-grown plants suffered an absolute loss of pectic uronate when incubated in that salt.

Journal Article↗

Cell wall composition and structure of Yarrowia lipolytica transposon mutants affected in calcofluor sensitivity.

A collection of transposon-mutagenized strains of Yarrowia lipolytica was screened for wall defects by determination of their sensitivity to calcofluor white. A number of strains were hypersensitive, whereas others were resistant. Different non-allelic mutants displayed increased sensitivity to autolysis and lytic enzymes, independently of whether they were sensitive or resistant to calcofluor white. A thorough analysis of their cell walls revealed minor quantitative alterations, and no significant changes in chitin content. Electrophoretic analysis of wall-bound and excreted proteins proved to be a sensitive method that revealed defects in the cell wall structure of the mutants. Important alterations in the patterns of the wall proteins extracted by SDS or by enzymatic treatments were noticed for the mutants, as compared to the parental strain. Mutants released to the growth medium a larger number of protein species than the parental strain, suggesting impairment in wall assembly of certain polypeptides. Patterns of wall-bound and excreted proteins, as well as alterations in wall chemical composition were not diagnostic of calcofluor white sensitivity or resistance, but were specific for each mutant. Our data show that an increase in either sensitivity or resistance of Y. lipolytica to certain levels of calcofluor is equally indicative of alterations in cell wall structure, independent of chitin levels.

Benzenesulfonates↗

Abnormal physiological properties and altered cell wall composition in Streptococcus pneumoniae grown in the presence of clavulanic acid.

Subinhibitory concentrations of clavulanate caused premature induction of stationary-phase autolysis, sensitization to lysozyme, and reductions in the MICs of deoxycholate and penicillin for Streptococcus pneumoniae. In the range of clavulanate concentrations producing these effects, this beta-lactam compound was selectively bound to PBP 3. Cell walls isolated from pneumococci grown in the presence of clavulanate showed increased sensitivity to the hydrolytic action of purified pneumococcal autolysin in vitro. High-performance liquid chromatography analysis of the peptidoglycan isolated from the clavulanate-grown cells showed major qualitative and quantitative changes in stem peptide composition, the most striking feature of which was the accumulation of peptide species carrying intact D-alanyl-D-alanine residues at the carboxy termini. The altered biological and biochemical properties of the clavulanate-grown pneumococci appear to be the consequences of suppressed D,D-carboxypeptidase activity.

Amino Acid Sequence↗

Effects of supercritical carbon dioxide (SC-CO(2)) oil extraction on the cell wall composition of almond fruits.

Extraction of oil from almond fruits using supercritical carbon dioxide (SC-CO(2)) was carried out at 50 degrees C and 330 bar on three sets of almonds: raw almond seeds, raw almond kernels, and toasted almond seeds. Three different oil extraction percentages were applied on each set ranging from approximately 15 to 16%, from approximately 27 to 33%, and from approximately 49 to 64%. Although no major changes were detected in the fatty acid composition between fresh and partially defatted samples, carbohydrate analysis of partially defatted materials revealed important changes in cell wall polysaccharides from almond tissues. Thus, at low extraction percentages (up to approximately 33%), pectic polysaccharides and hemicellulosic xyloglucans were the main type of polymers affected, suggesting the modification of the cell wall matrix, although without breakage of the walls. Then, as supercritical fluid extraction (SCFE) continues and higher extraction rates are achieved (up to approximately 64%), a major disruption of the cell wall occurred as indicated by the losses of all major types of cell wall polysaccharides, including cellulose. These results suggest that, under the conditions used for oil extraction using SC-CO(2), fatty acid chains are able to exit the cells through nonbroken walls; the modification of the pectin-hemicellulose network might have increased the porosity of the wall. However, as high pressure is being applied, there is a progressive breakage of the cell walls allowing the free transfer of the fatty acid chains from inside the cells. These findings might contribute to providing the basis for the optimization of SCFE procedures based on plant food sources.

Carbohydrates↗

Comparative studies on the cell wall composition of some anaerobic coryneforms of varying lympho-reticular stimulatory activity.

Anaerobic diphtheroids possessing lympho-reticular stimulatory properties may differ considerably in their peptidoglycan composition. Spleen weight-increasing activity of strains directly parallels their antitumour properties. P. granulosum strains, inactive in assays for lympho-reticular stimulation, appear to have a higher cell wall alanine content than most of the P. acnes and P. avidum strains tested. Two P. acnes strains, however, had equivalently high alanine ratios and were stimulatory. The presence of galactose does not appear to be required for activity since P. acnes II strains which lack this sugar can be fully stimulatory. The existence of the species P. lymphophilum (Torrey) is further supported by the finding of two more serologically identical strains which do not cross react serologically with the other species in the group. These organisms are fully stimulatory but have lysine rather than DAP as their cell wall diamino acid.

Animals↗