Composition and properties of the cell wall of Methanospirillum hungatii

1980 ◽  
Vol 26 (2) ◽  
pp. 115-120 ◽  
Author(s):  
G. D. Sprott ◽  
R. C. McKellar

Dithiothreitol reacted, at pH 9.0, with the isolated cell walls of Methanospirillum hungatii, to release about 23% of the cell wall dry weight as a high molecular weight fraction (> 0.5 million daltons). Untreated walls consisted of 70% amino acids, 11% lipid, and 6.6% carbohydrate. Sugars were identified as rhamnose, ribose, glucose, galactose, and mannose. The wall material that was released contained only 47% amino acids and was enriched in lipid, glucose, and phosphate. These results support data from electron micrographs, showing the localized release of cell wall material by the disulfide bond-breaking reagent at alkaline pH. In amino acid composition the untreated walls did not differ greatly from the material released by dithiothreitol, but differed considerably from the walls of another strain of M. hungatii. The ratios of the amino acids found in the cell wall proteins of several archaebacteria and of Bacillus cereus spore coats were similar.

Plants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2308
Author(s):  
Bojana Živanović ◽  
Sonja Milić Komić ◽  
Nenad Nikolić ◽  
Dragosav Mutavdžić ◽  
Tatjana Srećković ◽  
...  

Two tomato genotypes with constitutively different ABA level, flacca mutant and wild type of Ailsa Craig cv. (WT), were subjected to three repeated drought cycles, with the aim to reveal the role of the abscisic acid (ABA) threshold in developing drought tolerance. Differential responses to drought of two genotypes were obtained: more pronounced stomatal closure, ABA biosynthesis and proline accumulation in WT compared to the mutant were compensated by dry weight accumulation accompanied by transient redox disbalance in flacca. Fourier-transform infrared (FTIR) spectra analysis of isolated cell wall material and morphological parameter measurements on tomato leaves indicated changes in dry weight accumulation and carbon re-allocation to cell wall constituents in flacca, but not in WT. A higher proportion of cellulose, pectin and lignin in isolated cell walls from flacca leaves further increased with repeated drought cycles. Different ABA-dependent stomatal closure between drought cycles implies that acquisition of stomatal sensitivity may be a part of stress memory mechanism developed under given conditions. The regulatory role of ABA in the cell wall restructuring and growth regulation under low leaf potential was discussed with emphasis on the beneficial effects of drought priming in developing differential defense strategies against drought.


1969 ◽  
Vol 129 (1) ◽  
pp. 37-49 ◽  
Author(s):  
S. H. Ohanian ◽  
J. H. Schwab ◽  
W. J. Cromartie

Mice injected intraperitoneally with isolated cell wall fragments of Group A streptococci develop a carditis similar to that previously observed in mice injected with crude extracts of this organism. Neither the soluble cytoplasmic components of Group A streptococcal cells nor the nonfragmented cell walls produced carditis in this experimental model. Fluorescein and 125I-labeled antibodies specific for Group A streptococcal cell wall antigens were used to demonstrate that, for 5 wk after injection, cell wall material is localized around the sites of active lesions in the heart. In addition, the cell wall antigen accumulates in the liver, spleen, mediastinal lymph nodes, and the adjacent loose connective tissue, where it persists for at least 10 wk.


2018 ◽  
Vol 15 (8) ◽  
pp. 513
Author(s):  
Ewen Silvester ◽  
Annaleise R. Klein ◽  
Kerry L. Whitworth ◽  
Ljiljana Puskar ◽  
Mark J. Tobin

Environmental contextSphagnum moss is a widespread species in peatlands globally and responsible for a large fraction of carbon storage in these systems. We used synchrotron infrared microspectroscopy to characterise the acid-base properties of Sphagnum moss and the conditions under which calcium uptake can occur (essential for plant tissue integrity). The work allows a chemical model for Sphagnum distribution in the landscape to be proposed. AbstractSphagnum is one the major moss types responsible for the deposition of organic soils in peatland systems. The cell walls of this moss have a high proportion of carboxylated polysaccharides (polygalacturonic acids), which act as ion exchangers and are likely to be important for the structural integrity of the cell walls. We used synchrotron light source infrared microspectroscopy to characterise the acid-base and calcium complexation properties of the cell walls of Sphagnum cristatum stems, using freshly sectioned tissue confined in a flowing liquid cell with both normal water and D2O media. The Fourier transform infrared spectra of acid and base forms are consistent with those expected for protonated and deprotonated aliphatic carboxylic acids (such as uronic acids). Spectral deconvolution shows that the dominant aliphatic carboxylic groups in this material behave as a monoprotic acid (pKa=4.97–6.04). The cell wall material shows a high affinity for calcium, with a binding constant (K) in the range 103.9–104.7 (1:1 complex). The chemical complexation model developed here allows for the prediction of the chemical environment (e.g. pH, ionic content) under which Ca2+ uptake can occur, and provides an improved understanding for the observed distribution of Sphagnum in the landscape.


1957 ◽  
Vol 106 (3) ◽  
pp. 365-384 ◽  
Author(s):  
Richard M. Krause

The host ranges of bacteriophages for group A, types 1, 6, 12, and 25 and group C streptococci have been determined. The findings indicate that the susceptibility to these phages is primarily a group-specific phenomenon, although it is modified by several factors such as the hyaluronic acid capsule, lysogeny, and possibly the presence of surface proteins. Phage antibody studies indicate that while the group A phages are antigenically related, they are distinct from the group C phage. This is in agreement with the observation that group A phages are not specific for their homologous streptococcal types. The purified group C carbohydrate inactivates group C phage but not the group A phages, thus suggesting that the carbohydrate, a component of the cell wall, may serve as the phage receptor site. It has not been possible to inactivate the group A phages with group A carbohydrate. Phage lysis of groups A and C streptococci is accompanied by fragmentation of the cell wall since the C carbohydrate has been identified serologically and chemically in the supernate of centrifuged lysates. The immediate lysis of groups A and C hemolytic streptococci and their isolated cell walls by an accesory heat-labile lytic factor in fresh group C lysates is also described.


1959 ◽  
Vol 12 (4) ◽  
pp. 395 ◽  
Author(s):  
J Dainty ◽  
AB Hope

Measurements of ion exchange were made between isolated cell walls of Ohara australis and an external solution. Comparison between intact cells and cell walls showed that nearly all the easily exchangeable cations are located in the cell wall. The wall is hown to consist of "water free space" (W.F.S.) and "Donnan free space" (D.F.S.); the concentration of in diffusible anions in the D.F.S. is about O� 6 equivjl. This finding is contrary to past suggestions that the D.F.S. is in the cytoplasm of plant cells.


1968 ◽  
Vol 14 (7) ◽  
pp. 809-811 ◽  
Author(s):  
Chiu-Sheng Wang ◽  
Marvin N. Schwalb ◽  
Philip G. Miles

Mechanically isolated cell walls of normal homokaryons and the morphological mutants thin and puff were fractionated and hydrolyzed by chemical procedures. The yields of fractionated materials and the glucose/hexosamine ratios of acid hydrolysates were determined. Results of statistical analyses of the values obtained from these determinations indicated that single-gene mutations causing the thin and puff mutant forms of this fungus produce specific differences in the composition of cell walls.


1992 ◽  
Vol 70 (5) ◽  
pp. 933-941 ◽  
Author(s):  
E. Garnier-Sillam ◽  
I. Grech ◽  
Y. Czaninski ◽  
M.-T. Tollier ◽  
B. Monties

Free cell-wall residues were prepared by extracting wood samples of spruce (Populus euramericana cv. Fidzi Pauley) and poplar (Picea sitchensis). These species were chosen for their lignin types: guaiacyl in spruce and guaiacyl–syringyl in poplar. The parietal residues obtained were used as the sole food for the xylophagous termite Reticulitermes lucifugus var. santonensis and were compared before and after ingestion and transit in the digestive tracts. Differences due to the mechanical action of the gizzard were found in association with chemical changes. Polysaccharides were unmasked after digestion and could clearly be observed after reaction with periodic acid – thiocarbohydrazide – silver proteinate. A fibrillary meshwork was also observed inside the lignified cell walls. Biodegradation of cell wall material was particularly clear in poplar where granules formed an electron-dense plasma when uranyl acetate – lead citrate or periodic acid – thiocarbohydrazide – silver proteinate was used as a contrast medium. A selective biodegradation of syringyl monomers in poplar parietal residues was indicated by thioacidolysis but requires confirmation. Breakdown of lignified cell walls begins with a biodegradation of the lignin network associated with or followed by the digestion of polysaccharides. Syringyl-rich lignin fractions seemed to break down faster. Whether the enzymic pathway leading to ligninolysis originates from the termite digestive cells or from the endosymbionts present in their digestive tract lumen remains to be defined. Key words: Isoptera, Reticulitermes lucifugus var. santonensis, wood, lignin, spruce, poplar.


1969 ◽  
Vol 15 (4) ◽  
pp. 327-334
Author(s):  
M. P. Hatton

Preferential cell wall synthesis in Micrococcus lysodeikticus, as determined by an increase in the dry weight of the cell wall, took place in a medium containing DL-glutamic acid, DL-alanine, L-lysine, glycine, magnesium ions, glucose and phosphate buffer, pH 7.0. Cell wall synthesis could not be completely dissociated from protein synthesis in the 'cell wall' medium. The cell wall synthesized in the defined medium accounted for 40–56% of the total dry weight increase of the cells. Chloramphenicol had no effect on cell wall synthesis. Incorporation of uracil and guanine in the medium did not result in any increase in the amount of cell wall synthesized. DL-Glutamic acid alone, or a mixture of the three amino acids DL-alanine, L-lysine, and glycine, were capable of replacing the four amino acids present in the complete medium, but under these conditions the total dry weight of cell wall synthesized was only 75% of that produced in the complete medium. There was no reduction in cell wall synthesis when L-glutamic acid replaced DL-glutamic acid, L-alanine replaced DL-alanine, or sucrose replaced glucose in the cell wall medium. Deprivation of magnesium ions produced the greatest decrease in wall synthesis; this was the most important single factor involved in cell wall synthesis which was studied in the present investigation. There was no observable change in the chemical composition of the cell wall synthesized in the 'wall' medium when compared to that synthesized by cells grown in a complex medium.


1996 ◽  
Vol 74 (12) ◽  
pp. 1974-1981 ◽  
Author(s):  
C. Batisse ◽  
P. J. Coulomb ◽  
C. Coulomb ◽  
M. Buret

The changes in texture of fruits during ripening are linked to cell wall degradation involving synthesis and degradation of polymers. An increase in pectin solubility leads to cell sliding and an elastic aspect of tissues. The biochemical cell wall process differs between soft and crisp fruits originating from a same cultivar but cultivated under different agroclimatic conditions. Although the proportions of cell wall material are similar, the composition and structure of the two cell walls are very different at maturity. A solubilization of the middle lamella and a restructuration of the primary cell walls arising from the cells separation is observed in crisp fruits. In contrast, the middle lamella of the soft fruits is better preserved and the primary cell walls are thin and show degradation bags delimited by residual membrane formations. In addition, the macroendocytosis process by endosome individualization is more important in soft fruits. In conclusion, the fruit texture depends on the extent of the links between cell wall polymers. Keywords: cherry, cell wall, texture, ultrastructural study.


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