THE PHOSPHORUS FRACTIONS OF BACILLUS CEREUS AND BACILLUS MEGATERIUM: I. A COMPARISON OF SPORES AND VEGETATIVE CELLS

1955 ◽  
Vol 1 (7) ◽  
pp. 502-519 ◽  
Author(s):  
P. C. Fitz-James
Keyword(s):  
Nucleic Acid ◽  
Total Phosphorus ◽  
Cell Walls ◽  
Dry Weight ◽  
Phosphorus Fractions ◽  
Weight Basis ◽  
Insoluble Residue ◽  
Vegetative Cells ◽  
Acid Labile ◽  
Total P

The phosphorus fractions of the spores and young vegetative cells of B. cereus and B. megaterium were compared using the methods of Schneider and of Schmidt and Thannhauser. Differences were found, not only between the two types of cell, but also between the species studied. The spores of B. cereus and B. megaterium contained, on a dry weight basis, similar amounts of nucleic acid, yet the spores of B. megaterium contained twice as much total phosphorus as those of B. cereus. The excess phosphorus of B. megaterium spores was present as an acid and alkali insoluble residue and was made up of empty spore coats. While this same fraction accounted for only 4% of the total phosphorus of B. cereus spores it made up some 60% of that of B. megaterium. A similar fraction from vegetative cells was low in phosphorus. The spore coats of B. megaterium, in contrast to the cell walls were lysozyme-resistant. Cold acid-soluble and lipid phosphorus could be properly estimated only on disrupted spores. Disruption also proved essential for the ready extraction of spore nucleic acids with hot TCA, but did not greatly alter the solubility of the residue phosphorus. Ribosenucleic acid (RNA) comprised 50% of the total phosphorus in the spores of B. cereus (3–4% of the dry weight) but only 25% in B. megaterium spores. In both species the RNA of the vegetative forms accounted for a larger proportion of the total P of the cell. Ribonuclease digested the RNA of spores and vegetative cells to the same degree. The Schmidt and Thannhauser method was found more suitable than the Schneider method for the estimation of desoxyribosenucleic acid (DNA). The DNA content of B. cereus spores was about 1% of their dry weight; that of B. megaterium spores was slightly less. Some 12–20% of the phosphorus of B. cereus spores and 6% of that of the young vegetative cells was present as acid-labile (non-nucleic acid) phosphorus which exhibited some of the characteristics of polymetaphosphate.

scholarly journals Isolation and partial characterization of apiogalacturonans from the cell wall of Lemna minor

1970 ◽  
Vol 116 (4) ◽  
pp. 569-579 ◽  
Author(s):  
David A. Hart ◽  
Paul K. Kindel
Keyword(s):  
Cell Wall ◽  
Sodium Chloride ◽  
Cell Walls ◽  
Lemna Minor ◽  
Extraction Procedure ◽  
Ammonium Oxalate ◽  
Periodate Oxidation ◽  
Dry Weight ◽  
Weight Basis ◽  
Sephadex Column

1. A mild, reproducible extraction procedure, using 0.5% ammonium oxalate, was developed for the isolation of polysaccharides containing d-apiose from the cell wall of Lemna minor. On a dry-weight basis the polysaccharide fractions extracted with ammonium oxalate made up 14% of the material designated cell walls and contained 20% of the d-apiose originally present in the cell walls. The cell walls, as isolated, contained 83% of the d-apiose present in L. minor. 2. After extraction with ammonium oxalate, purified polysaccharides were obtained by DEAE-Sephadex column chromatography and by fractional precipitation with sodium chloride. With these procedures the material extracted at 22°C could be separated into at least five polysaccharides. On a dry-weight basis two of these polysaccharides made up more than 50% of the material extracted at 22°C. There was a direct relationship between the d-apiose content of the polysaccharides and their solubility in sodium chloride solutions; those of highest d-apiose content were most soluble. 3. All the polysaccharides isolated appeared to be of one general type, namely galacturonans to which were attached side chains containing d-apiose. The d-apiose content of the apiogalacturonans varied from 7.9 to 38.1%. The content of esterified d-galacturonic acid residues in all apiogalacturonans was low, being in the range 1.0–3.5%. Hydrolysis of a representative apiogalacturonan with dilute acid resulted in the complete removal of the d-apiose with little or no degradation of the galacturonan portion. 4. Treatment of polysaccharide fractions with pectinase established that those of high d-apiose content and soluble in m-sodium chloride were not degraded, whereas those of low d-apiose content and insoluble in m-sodium chloride were extensively degraded. When the d-apiose was removed from a typical pectinase-resistant polysaccharide, the remainder of the polysaccharide was readily degraded by this enzyme. 5. Periodate oxidation of representative polysaccharide fractions and apiogalacturonans and determination of the formaldehyde released showed that about 50% of the d-apiose molecules were substituted at either the 3- or the 3′-position.

scholarly journals Carbohydrates of Human and Bovine Platelets

Blood ◽  
1960 ◽  
Vol 16 (2) ◽  
pp. 1173-1183 ◽  
Author(s):  
E. E. WOODSIDE ◽  
W. KOCHOLATY
Keyword(s):  
Sialic Acid ◽  
Whole Blood ◽  
Glucuronic Acid ◽  
Dry Weight ◽  
Human Platelets ◽  
Weight Basis ◽  
Insoluble Residue ◽  
Total Carbohydrate ◽  
Ethanol Precipitation ◽  
Total Carbohydrate Content

Abstract 1. Average values for the total carbohydrate content of human and bovine platelets were 8.47 and 8.77 per cent of the dry weight, respectively. On a dry weight basis, human platelets were calculated to be approximately one-third larger than bovine platelets. By chemical and chromatographic analysis, glucose, galactose, mannose, fucose, ribose, glucosamine, galactosamine, glucuronic acid and sialic acid were detected in both human and bovine platelets. 2. Glucose and ribose were found to be the only monomers present in the 5 per cent TCA-soluble fractions of both human and bovine platelets. The TCA-insoluble residue contained glucose, galactose, mannose, fucose, ribose, glucuronic acid, glucosamine, galactosamine and sialic acid. The acid mucopolysaccharide fraction of both human and bovine platelets contained galactosamine and glucuronic acid monomers as well as galactose, glucose, and ribose. 3. Glycogen was found in both human and bovine platelets. Total glycogen was extracted by 5 per cent TCA from sonorated human and bovine p1atelets; however, subsequent ethanol precipitation of tile glycogen was incomplete. In contrast, 30 per cent KOH extraction followed by ethanol precipitation resulted in complete recoveries of the glycogen. 4. Variations ill both total hexose and glycogen contents were found in both human and bovine platelets. These variations were partially dependent on the length of storage of the platelets in whole blood or in 0.85 per cent NaCl after separation from whole blood.

Survival and Growth of Psychrotrophic Bacillus cereus in Dry and Reconstituted Infant Rice Cereal

1998 ◽  
Vol 61 (12) ◽  
pp. 1629-1635 ◽  
Author(s):  
CYNTHIA B. JAQUETTE ◽  
LARRY R. BEUCHAT
Keyword(s):  
Detection Limit ◽  
Bacillus Cereus ◽  
Water Activity ◽  
Apple Juice ◽  
Dry Weight ◽  
Weight Basis ◽  
Effect Of Temperature ◽  
Vegetative Cells ◽  
Infant Foods ◽  
Survival And Growth

The potential for growth of enterotoxigenic Bacillus cereus in reconstituted dry foods is a concern, especially when they are consumed by infants or the immunosuppressed. The ability of a four-strain mixture of spores or vegetative cells of psychrotrophic B. cereus to survive in a commercial, dry infant rice cereal as affected by water activity (aw; 0.27 to 0.28, 0.52 to 0.55, and 0.75 to 0.78), pH (5.6 and 6.7), and temperature (5, 25, 35, and 45°C) was investigated. The rate of death of vegetative cells in dry cereal stored for 36 weeks was not affected by aw or pH. Death of spores in cereal stored at 45°C for up to 48 weeks was enhanced at aw 0.78 but was unaffected by pH; loss of viability at 5, 25, and 35°C was largely unaffected by differences in aw. The effect of temperature (8, 15, 21, and 30°C) on outgrowth of spores of B. cereus inoculated at three levels (0.14, 14, and 133 CFU/g, dry weight basis) into cereal reconstituted with apple juice and commercial pasteurized milk (2% fat) was also studied. Outgrowth of spores did not occur in cereal reconstituted with apple juice. Cereal reconstituted with milk and inoculated with 0.14,14, and 133 spores per g contained >3 log CFU/g within 24, 9, and 6 h, respectively, at 21°C. Populations in cereal reconstituted with milk and inoculated with 133 CFU of B. cereus spores per g reached 7.11, 7.72, and 7.40 log CFU/g within 12, 48, and 72 h when stored at 30, 21, and 15°C, respectively. The organism grew in cereal reconstituted with milk and held at 8°C for 72 h; however, enterotoxin was not detected. In reconstituted cereal inoculated with 133 spores per g, enterotoxin was detected (detection limit 16 ng/g) after 24, 48, and 72 h at 30, 21, and 15°C, respectively, when the population of B. cereus reached >7 log CFU/g. It is recommended that reconstituted infant foods be either consumed immediately or held at ≤8°C and consumed within 48 h after preparation.

Influence of calcium on the metabolism of chlorophyll, carotene, nucleic acid, and protein in Scenedesmus

1973 ◽  
Vol 51 (1) ◽  
pp. 121-125 ◽  
Author(s):  
Gaurangakumar Das
Keyword(s):  
Nucleic Acid ◽  
Protein Content ◽  
Dna Content ◽  
Culture Medium ◽  
Growth Period ◽  
Dry Weight ◽  
Weight Basis ◽  
Carotene Content ◽  
Calcium Supply

The influence of calcium supply on the chlorophyll, carotene, nucleic acid, and protein content in Scenedesmus obtusiusculus Chod. was investigated. Evidence showed that upon addition of calcium-starved cells to a culture medium containing calcium, the levels of all these components increased slowly for 15 h. During the next 33 h chlorophyll and carotene content increased more rapidly, and the chlorophyll a:b ratio also increased. During this growth period, both RNA and protein content increased linearly whereas DNA content did not increase on a dry weight basis throughout the period of observation.

Possible mechanism of gibberellin-induced chlorosis in lettuce seedlings

1973 ◽  
Vol 51 (1) ◽  
pp. 175-184 ◽  
Author(s):  
Gaurangakumar Das
Keyword(s):  
Nucleic Acid ◽  
Protein Content ◽  
Sugar Content ◽  
Dry Weight ◽  
Weight Basis ◽  
Nucleic Acid Content ◽  
Chlorophyll B ◽  
Lactuca Sativa L ◽  
Grand Rapids ◽  
Rna And Dna

Effects of gibberellin A3 (GA) on growth, pigments, protein, and nucleic acid content of the cotyledons of lettuce seedlings (Lactuca sativa L. cv. Grand Rapids) are reported. GA treatment increased both the total shoot and cotyledon fresh weights, and decreased chlorophyll content per cotyledon and on a dry weight basis. GA also decreased the protein content of the cotyledon, but increased the level of RNA and DNA measured on a dry weight basis. The hormone had no effect on the pheophytin: chlorophyll ratio, but increased the ratios of chlorophyll a: chlorophyll b, phytol: chlorophyll, and carotene: chlorophyll. GA also increased the sugar content of the cotyledons. Treatment of excised cotyledons with glucose had an effect similar to that of GA on chlorophyll and protein content. The data are discussed in relation to the mechanism of GA-induced chlorosis.

ERRORS ASSOCIATED WITH HERBAGE DISSECTION ANALYSES 2. Problems of species identification

1976 ◽  
pp. 213-225
Author(s):  
I.M. Ritchie ◽  
C.C. Boswell ◽  
A.M. Badland
Keyword(s):  
New Zealand ◽  
Dry Weight ◽  
Analytical Tool ◽  
Species Level ◽  
Weight Basis ◽  
Plant Identification ◽  
Leaf Fragment ◽  
Research Division ◽  
Or Groups ◽  
Botanical Analysis

HERBACE DISSECTION is the process in which samples of herbage cut from trials are separated by hand into component species. Heavy reliance is placed on herbage dissection as an analytical tool ,in New Zealand, and in the four botanical analysis laboratories in the Research Division of the Ministry of Agriculture and Fisheries about 20 000 samples are analysed each year. In the laboratory a representative subsample is taken by a rigorous quartering procedure until approximately 400 pieces of herbage remain. Each leaf fragment is then identified to species level or groups of these as appropriate. The fractions are then dried and the composition calculated on a percentage dry weight basis. The accuracy of the analyses of these laboratories has been monitored by a system of interchanging herbage dissection samples between them. From this, the need to separate subsampling errors from problems of plant identification was, appreciated and some of this work is described here.

Polycyclic Aromatic Hydrocarbons (PAHs) in Sediments of the Brisbane River (Australia) – Preliminary Results

1989 ◽  
Vol 21 (2) ◽  
pp. 161-165 ◽  
Author(s):  
S. I. Kayal ◽  
D. W. Connell
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
River Estuary ◽  
Dry Weight ◽  
Weight Basis ◽  
Sediment Samples ◽  
Preliminary Results ◽  
Treated Sewage ◽  
Polycyclic Aromatic ◽  
Petroleum Refineries

Results of the analysis of twenty-three composite sediment samples revealed that PAHs are widely distributed in the Brisbane River estuary. Mean concentrations for individual compounds, on a dry weight basis, ranged from 0.03 µg/g for dibenz [ah] anthracene to 2.34 µg/g for fluoranthene. Observed PAH assemblages were rich in compounds having pyrolytic origins. However, the presence of petroleum derived compounds was indicative of the importance of petroleum as a PAH source in the estuary. Petroleum refineries, a coal loading terminal and a major treated sewage outfall located at the mouth were not indicated as major contributing sources of PAH pollution in the estuary.

Mineral nutrition, dinitrogen fixation, and growth of Alnuscrispa and Alnusglutinosa

1985 ◽  
Vol 15 (5) ◽  
pp. 855-861 ◽  
Author(s):  
G. Prégent ◽  
C. Camiré
Keyword(s):  
Mineral Nutrition ◽  
Dry Weight ◽  
Optimal Growth ◽  
Maximum Growth ◽  
Dinitrogen Fixation ◽  
Weight Basis ◽  
Critical Levels ◽  
N Status

Invitro cultures of Alnuscrispa (Ait.) Pursh and Alnusglutinosa (L.) Gaertn. were used to estimate critical foliage levels of selected nutrients for optimal growth and dinitrogen (N2) fixation. For A. crispa to obtain 90% of maximum growth and N2 fixation, foliar levels of 0.12% P, 0.13% Mg, <0.31% K, and <0.04% Ca on a dry weight basis were needed. For A. glutinosa, the critical levels were 0.138% P, 0.10% Mg, 0.29% Ca, and ~0.20% K. From all the deficiencies observed, P had the more pronounced effects on N status of both species.

SOLUBLE SUGAR CHANGES OCCURRING DURING COLD HARDENING OF SPRING WHEAT, FALL RYE AND ALFALFA

1983 ◽  
Vol 63 (2) ◽  
pp. 415-420 ◽  
Author(s):  
D. G. GREEN
Keyword(s):  
Spring Wheat ◽  
Soluble Sugar ◽  
Soluble Sugars ◽  
Dry Weight ◽  
Weight Basis ◽  
Cold Hardening ◽  
Spring Type

Alfa, a relatively nonhardy alfalfa cultivar continued to accumulate, on a dry weight basis, fructose, α- and β-D-glucose, sucrose and maltose during the latter stages of cold hardening. Rambler, a hardier alfalfa cultivar conversely showed a decrease for these soluble sugars with hardening. Frontier rye, a very hardy winter habit cereal showed decreases in these soluble sugars plus melibiose during the same hardening period. These results support the hypothesis that hardy cereals and alfalfa undergo a decrease in soluble sugars with hardening, while less hardy cereals and alfalfa continue to increase in content of soluble sugars. Manitou wheat appeared not to fit this hypothesis and showed the decreased soluble sugars usually associated with hardy cultivars. Although Manitou is a spring type wheat, one of its parents, Thatcher, does contain gene(s) for the winter habit.Key words: Sugar, cold hardening, wheat, rye, alfalfa

scholarly journals THE MOLECULAR WEIGHT OF RHODOPSIN AND THE NATURE OF THE RHODOPSIN-DIGITONIN COMPLEX

1954 ◽  
Vol 37 (3) ◽  
pp. 381-399 ◽  
Author(s):  
Ruth Hubbard
Keyword(s):  
Molecular Weight ◽  
Single Molecule ◽  
Extinction Coefficient ◽  
Dry Weight ◽  
Weight Basis ◽  
Sedimentation Behavior ◽  
A Value ◽  
Wet Weight ◽  
Single Boundary ◽  
Stoichiometric Complex

The sedimentation behavior of aqueous solutions of digitonin and of cattle rhodopsin in digitonin has been examined in the ultracentrifuge. In confirmation of earlier work, digitonin was found to sediment as a micelle (D-1) with an s20 of about 6.35 Svedberg units, and containing at least 60 molecules. The rhodopsin solutions sediment as a stoichiometric complex of rhodopsin with digitonin (RD-1) with an s20 of about 9.77 Svedberg units. The s20 of the RD-1 micelle is constant between pH 6.3 and 9.6, and in the presence of excess digitonin. RD-1 travels as a single boundary also in the electrophoresis apparatus at pH 8.5, and on filter paper at pH 8.0. The molecular weight of the RD-1 micelle lies between 260,000 and 290,000. Of this, only about 40,000 gm. are due to rhodopsin; the rest is digitonin (180 to 200 moles). Comparison of the relative concentrations of RD-1 and retinene in solutions of rhodopsin-digitonin shows that RD-1 contains only one retinene equivalent. It can therefore contain only one molecule of rhodopsin with a molecular weight of about 40,000. Cattle rhodopsin therefore contains only one chromophore consisting of a single molecule of retinene. It is likely that frog rhodopsin has a similar molecular weight and also contains only one chromophore per molecule. The molar extinction coefficient of rhodopsin is therefore identical with the extinction coefficient per mole of retinene (40,600 cm.2 per mole) and the E(1 per cent, 1 cm., 500 mµ) has a value of about 10. Rhodopsin constitutes about 14 per cent of the dry weight, and 3.7 per cent of the wet weight of cattle outer limbs. This corresponds to about 4.2 x 106 molecules of rhodopsin per outer limb. The rhodopsin content of frog outer limbs is considerably higher: about 35 per cent of the dry weight, and 10 per cent of the wet weight, corresponding to about 2.1 x 109 molecules per outer limb. Thus the frog outer limb contains about five hundred times as much rhodopsin as the cattle outer limb. But the relative volumes of these structures are such that the ratio of concentrations is only about 2.5 to 1 on a weight basis. Rhodopsin accounts for at least one-fifth of the total protein of the cattle outer limb; for the frog, this value must be higher. The extinction (K500) along its axis is about 0.037 cm.2 for the cattle outer limb, and about 0.50 cm.2 for the frog outer limb.

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