EFFECT OF SALT CONCENTRATION ON THE MORPHOLOGY AND CHEMICAL COMPOSITION OF MICROCOCCUS HALODENITRIFICANS

1959 ◽  
Vol 5 (1) ◽  
pp. 25-35 ◽  
Author(s):  
I. Takahashi ◽  
N. E. Gibbons
Keyword(s):  
Growth Medium ◽  
Salt Concentration ◽  
Osmotic Shock ◽  
Salt Content ◽  
Diaminopimelic Acid ◽  
Wall Material ◽  
Cell Wall Material ◽  
Quantitative Estimates ◽  
Nitrogen Ratio ◽  
In Cells

Cells of Micrococcus halodenitrificans grown in media containing more than 0.7 M sodium chloride appeared normal microscopically, but in 0.6 M salt many cells were swollen and in 0.55 M salt most cells were swollen or ruptured. The swollen cells were sensitive to osmotic shock. Calcium or magnesium prevented the cells from swelling and extended the lower limit of growth from 0.55 to 0.3 M salt. Walls of normal cells contained 6 carbohydrates and 16 amino acids. Qualitative chromatographic analyses indicated that cells grown in 0.55 M salt contained less tyrosine, diaminopimelic acid, and an unknown ninhydrin-positive, cytoplasmic component than cells grown in 1.0 M salt. Quantitative estimates indicated that diaminopimelic acid/nitrogen ratio in cells decreased gradually from 0.25 to 0.16 as the salt content of the growth medium decreased from 1.0 to 0.55 M, but that it decreased to 0.003 in cells grown in 0.3 M salt plus calcium. The results suggest that less cell wall material is produced as the salt concentration in the growth medium is decreased and that calcium has a protective effect on the weakened cells or protoplasts.

The digestion of bacterial mucopeptide constituents in the sheep: 1. The metabolism of 2, 6-diaminopimelic acid

1971 ◽  
Vol 77 (1) ◽  
pp. 91-98 ◽  
Author(s):  
V. C. Mason ◽  
F. White
Keyword(s):  
Terminal Ileum ◽  
Amino Nitrogen ◽  
Diaminopimelic Acid ◽  
Wall Material ◽  
Cell Wall Material ◽  
Jugular Veins ◽  
Adult Sheep ◽  
Series Of Experiments ◽  
Extensive Degradation ◽  
Hind Gut

Summary1. In a series of experiments with cannulated lambs the amounts of 2, 6-diaminopimelic acid (DAPA) and a-amino nitrogen passing daily through the abomasum, terminal ileum and rectum were measured. While there was a very significant net absorption of α-amino nitrogen between the abomasum and terminal ileum, there was no net absorption of DAPA between these points. Indeed, there was a tendency for more DAPA to leave the terminal ileum than entered the abomasum, though this was only significant at the 10% level. In all cases significantly less DAPA passed out of the rectum than passed through the terminal ileum, indicating extensive degradation of this amino acid in the hind-gut, probably as a result of microbial activity.2. In adult sheep given control rations no DAPA could be detected in the blood, even when 643 ml plasma were analysed. These sheep usually excreted less than 5 mg DAPA daily in the urine.3. When synthetic DAPA was introduced into the peritoneum, blood, abomasum, rumen or caecum of cannulated adult sheep in physiological amounts, approximately 80, 83, 53, 5 and 0 % of the administered dose was recovered in the urine. Furthermore, when introduced into the abomasum, DAPA could be measured in plasma from the anterior mesenteric and jugular veins.4. It was concluded that in the normal sheep the DAPA-containing fraction of the bacterial cell-wall material synthesized in the rumen is not digested in the small intestine. In the caecum and colon, however, this fraction is extensively degraded by hindgut bacteria.

scholarly journals Viral lysis of bacteria: an important source of dissolved amino acids and cell wall compounds

2006 ◽  
Vol 86 (3) ◽  
pp. 605-612 ◽  
Author(s):  
Mathias Middelboe ◽  
Niels O.G. Jørgensen
Keyword(s):  
Amino Acids ◽  
Cell Wall ◽  
Organic Matter ◽  
Organic Carbon ◽  
Bacterial Cell ◽  
Bacterial Cell Wall ◽  
Diaminopimelic Acid ◽  
Wall Material ◽  
Cell Wall Material ◽  
Viral Lysis

Viral infection of bacteria causes release of dissolved organic matter (DOM), which is available for bacterial uptake. In aquatic environments, this virus-mediated transformation of living cells into dissolved and colloidal organic matter may be a quantitatively important process in the pelagic recycling of carbon and nutrients, but little is known about the amount, composition, or bioavailability of viral lysates. By using a model system of a marine bacterium (Cellulophaga sp.) and a virus specific to this bacterium, the present study provides a first quantification of the input of dissolved free and combined amino acids (DFAA and DCAA) and bacterial cell wall compounds following viral lysis. The DCAA constituted 51–86% of the total virus-mediated organic carbon release of 1087–1825 μg C l−1 (estimated biomass of the lysed bacteria), whereas DFAA and glucosamine each accounted for 2–3% of total lysate-C. The viral particles themselves constituted 4–6% of the released organic carbon, and altogether, the applied analyses thus identified 53–92% of the released lysates. Approximately 12% of the identified compounds were derived from bacterial cell wall peptidoglycan, including various D-isomers of DFAA and DCAA, glucosamine and diaminopimelic acid (DAPA). Although a portion of this cell wall material may have entered the pool of refractory material, a significant fraction of some peptidoglycan-derived components, e.g. 83% of the released D-DFAA, were removed from the dissolved phase during the last part of the incubations, suggesting that part of the cell wall material were utilized by the developing virus-resistant Cellulophaga population. Therefore, we suggest that virus-mediated DOM is a source of a variety of organic compounds, which contribute significantly to the pool of rapidly recycling material in the ocean.

scholarly journals Influence of Salt on the Self-Organization in Solutions of Star-Shaped Poly-2-alkyl-2-oxazoline and Poly-2-alkyl-2-oxazine on Heating

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1152
Author(s):  
Tatyana Kirila ◽  
Anna Smirnova ◽  
Alla Razina ◽  
Andrey Tenkovtsev ◽  
Alexander Filippov
Keyword(s):  
Phase Separation ◽  
Salt Concentration ◽  
Monomer Unit ◽  
Salt Content ◽  
The Self ◽  
Self Organization ◽  
Phase Separation Temperature ◽  
The Core ◽  
Separation Temperature ◽  
Water Salt

The water–salt solutions of star-shaped six-arm poly-2-alkyl-2-oxazines and poly-2-alkyl-2-oxazolines were studied by light scattering and turbidimetry. The core was hexaaza[26]orthoparacyclophane and the arms were poly-2-ethyl-2-oxazine, poly-2-isopropyl-2-oxazine, poly-2-ethyl-2-oxazoline, and poly-2-isopropyl-2-oxazoline. NaCl and N-methylpyridinium p-toluenesulfonate were used as salts. Their concentration varied from 0–0.154 M. On heating, a phase transition was observed in all studied solutions. It was found that the effect of salt on the thermosensitivity of the investigated stars depends on the structure of the salt and polymer and on the salt content in the solution. The phase separation temperature decreased with an increase in the hydrophobicity of the polymers, which is caused by both a growth of the side radical size and an elongation of the monomer unit. For NaCl solutions, the phase separation temperature monotonically decreased with growth of salt concentration. In solutions with methylpyridinium p-toluenesulfonate, the dependence of the phase separation temperature on the salt concentration was non-monotonic with minimum at salt concentration corresponding to one salt molecule per one arm of a polymer star. Poly-2-alkyl-2-oxazine and poly-2-alkyl-2-oxazoline stars with a hexaaza[26]orthoparacyclophane core are more sensitive to the presence of salt in solution than the similar stars with a calix[n]arene branching center.

Synchrotron infrared microspectroscopy reveals the response of Sphagnum cell wall material to its aqueous chemical environment

2018 ◽  
Vol 15 (8) ◽  
pp. 513
Author(s):  
Ewen Silvester ◽  
Annaleise R. Klein ◽  
Kerry L. Whitworth ◽  
Ljiljana Puskar ◽  
Mark J. Tobin
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Chemical Environment ◽  
Wall Material ◽  
Organic Soils ◽  
Cell Wall Material ◽  
Acid Base ◽  
Widespread Species ◽  
Flowing Liquid ◽  
Infrared Microspectroscopy

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.

Inhibition of the Synthesis of Wax D Peptidoglycolipid of Mycobacterium tuberculosis by d -Cycloserine

1970 ◽  
Vol 1 (1) ◽  
pp. 74-77 ◽  
Author(s):  
Hugo L. David ◽  
Dexter S. Goldman ◽  
Kuni Takayama
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Functional Group ◽  
Diaminopimelic Acid ◽  
Inhibition Of Growth ◽  
In Cells

The antibiotic d -cycloserine inhibits the synthesis of the wax D peptidoglycolipid in cells of the H37Ra strain of Mycobacterium tuberculosis . This inhibition occurs at a lower concentration of the drug than that required for the inhibition of growth. The inhibition is completely reversed by d -alanine. An arabino-galactan-galactosamine-(diaminopimelic acid)-mycolate accumulates in H37Ra cells exposed to the antibiotic. The chemical and functional group analyses of this lipid suggests it to be a possible precursor to the synthesis of wax D.

scholarly journals Influence of Lignin on Digestibility of Forage Cell Wall Material

1986 ◽  
Vol 62 (6) ◽  
pp. 1703-1712 ◽  
Author(s):  
H. G. Jung ◽  
K. P. Vogel
Keyword(s):  
Cell Wall ◽  
Wall Material ◽  
Cell Wall Material
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