scholarly journals An examination of the inhibitory effects of N-iodoacetylglucosamine on Escherichia coli and isolation of resistant mutants

1970 ◽  
Vol 118 (1) ◽  
pp. 81-87 ◽  
Author(s):  
R. J. White ◽  
P. W. Kent
Keyword(s):  
Escherichia Coli ◽  
Trichloroacetic Acid ◽  
Soluble Fraction ◽  
Early Stage ◽  
Alkylating Agents ◽  
Insoluble Fraction ◽  
Inhibitory Effects ◽  
Macromolecular Synthesis ◽  
Whole Cells ◽  
Resistant Mutants

1. After incubation of Escherichia coli with N-iodo[1,2-14C2]acetylglucosamine, 95–99% of the 14C taken up by whole cells is located in a cold-trichloroacetic acid-soluble fraction. Two major components of this fraction are S-carboxymethylcysteine and S-carboxymethylglutathione. The same compounds accumulate during incubation with iodo[14C]acetate but not with iodo[14C]acetamide. The amount of 14C associated with a cold-trichloroacetic acid-insoluble fraction are comparable for all three alkylating agents. After incubation with iodo[14C]acetamide, 50% of the label bound to whole cells is recoverable in a cold-trichloroacetic acid-insoluble fraction. 2. Uptake and incorporation of 14C from [U-14C]glycerol is blocked at an early stage by N-iodoacetylglucosamine. No specific inhibition of macromolecular synthesis could be demonstrated. 3. Mutants selected for resistance to iodoacetate are partially resistant to iodoacetate and N-iodoacetylglucosamine, but show no resistance to iodoacetamide. 4. Mutants selected for resistance to N-iodoacetylglucosamine are not resistant to iodoacetate or iodoacetamide, and are defective in their ability to grow on N-acetylglucosamine. Resistance to N-iodoacetylglucosamine is not absolute, and depends on the presence of glucose or certain other sugars; there is no resistance during growth on maltose, glycerol or succinate. 5. Absolute resistance can be achieved by selecting for a second mutation conferring resistance during growth on maltose; double mutants isolated by this procedure are unable to grow on N-acetylglucosamine and grow poorly on glucosamine. Resistant single mutants have a slightly diminished uptake of N-acetyl[1-14C]glucosamine, but in resistant double mutants the uptake of both [1-14C]glucosamine and N-acetyl[1-14C]glucosamine is severely diminished. 6. These observations are consistent with the presence of two permeases for N-acetylglucosamine, one that also permits uptake of glucosamine and another that allows entry of methyl 2-acetamido-2-deoxy-α-d-glucoside. N-Iodoacetylglucosamine can gain entry to the cell by both permeases.

STUDIES OF ASPOROGENIC MUTANTS OF BACILLUS CEREUS: PRELIMINARY INVESTIGATIONS WITH CALCIUM AND ZINC

1962 ◽  
Vol 8 (6) ◽  
pp. 823-833 ◽  
Author(s):  
J. J. Cooney ◽  
D. G. Lundgren
Keyword(s):  
Heat Resistance ◽  
Bacillus Cereus ◽  
Trichloroacetic Acid ◽  
Minimal Medium ◽  
Soluble Fraction ◽  
Dipicolinic Acid ◽  
Insoluble Fraction ◽  
Temperature Sensitive ◽  
Vegetative Cells ◽  
Culture Cycle

The physiology of spore formation was studied in Bacillus cereus and a temperature-sensitive asporogenic mutant. The parent organism sporulates when cultured in a minimal medium at either 28 °C or 37 °C while the mutant sporulates only at 28 °C. The blocking of sporulation at 37 °C has been referred to as "abortive" sporulation. Uptake of calcium and zinc was followed during growth and sporulation or "abortive" sporulation. Calcium and dipicolinic acid (DPA) levels in sporogenic cultures increased as the medium calcium was increased. The asporogenic mutant took up less calcium and synthesized little DPA. Heat resistance of spores increased as the calcium and DPA increased. Over 99% of Ca45or Zn65were released from labelled spores when autoclaved to release DPA. Chemical fractionations were made of cells labelled with Zn65and Ca45and harvested at different times during the culture cycle. Smaller percentages of calcium than of zinc were located in the cold trichloroacetic acid soluble fraction. The alcohol-soluble, ether-insoluble fraction of spores contained a greater percentage of calcium than was found in vegetative cells. Cells which had undergone "abortive" sporulation contained the same percentage of calcium in this fraction as homologous vegetative cells.

scholarly journals The membrane lipids of Halobacterium halobium

1968 ◽  
Vol 110 (3) ◽  
pp. 441-448 ◽  
Author(s):  
Carolyn L. Marshall ◽  
A. D. Brown
Keyword(s):  
Membrane Lipids ◽  
Soluble Fraction ◽  
Growth Cycle ◽  
Insoluble Fraction ◽  
Halobacterium Halobium ◽  
Lipid Phosphorus ◽  
Lipid Mixture ◽  
Whole Cells ◽  
Acetone Insoluble ◽  
Lipid Mixtures

The lipid content of the cell membrane of Halobacterium halobium increased from about 15% to 21% during exponential growth of the organism. Total lipid phosphorus more than doubled during the growth cycle. The mixture of membrane lipids from stationary-phase organisms was similar to lipid mixtures from whole cells of other halobacteria inasmuch as 80% of the lipid phosphorus occurred in a diether analogue of phosphatidylglycerophosphate and an additional 7·5% occurred in the ether analogue of phosphatidylglycerol. The lipid mixture was more complex than those reported for other halophils, however, 12 components being recognized in the acetone-insoluble fraction and 17 in the acetone-soluble fraction. There were major changes in the proportions of some minor components of the acetone-insoluble fraction during a growth cycle. Three nitrogenous lipids were recognized in the acetone-insoluble fraction, but all were present in relatively low proportion. One, which was not a phospholipid, contained a bound peptide. Of the 17 acetonesoluble compounds, 15 were pigments. The major carotenoids were α- and β-bacteriorubrin. The carotenoid pigments occurred at maximal concentration after 6–7 days' growth.

Distribution of dietary limiting amino acid injected into the prepyriform cortex

1991 ◽  
Vol 260 (3) ◽  
pp. R525-R532
Author(s):  
J. L. Beverly ◽  
B. J. Hrupka ◽  
D. W. Gietzen ◽  
Q. R. Rogers
Keyword(s):  
Amino Acid ◽  
Injection Site ◽  
Trichloroacetic Acid ◽  
Soluble Fraction ◽  
Time Lag ◽  
Insoluble Fraction ◽  
Feeding Response ◽  
Limiting Amino Acid ◽  
Limited Diffusion ◽  
Prepyriform Cortex

Diffusion or metabolism of the dietary limiting amino acid (DLAA) in the prepyriform cortex (PPC) may account for the time lag between injection of the DLAA into the PPC and the increase in intake of an amino acid-imbalanced diet. Results from the injection of [3H]Leu +/- [14C]Thr (DLAA) into the PPC indicated rapid (less than 15 min) and limited diffusion (85-90% of recovered label was less than or equal to 1 mm from the injection site). 3H and 14C decreased in the trichloroacetic acid (TCA)-soluble fraction and increased in the TCA-insoluble fraction during the first 1.5 h and remained constant in the TCA-insoluble fraction 1.5-6 h after injection. An increase (approximately 50%) in 3H in the TCA-insoluble fraction was found less than or equal to 30 min after injection of the DLAA. There was no affect of the DLAA on 3H in the TCA-soluble fraction. These results indicated that a change in metabolism within the PPC may be responsible for the delay in onset of the feeding response after injection of the DLAA into the PPC.

scholarly journals Utilization of the nucleic acids ofEscherichia coliand rumen bacteria by sheep

1974 ◽  
Vol 32 (3) ◽  
pp. 529-537 ◽  
Author(s):  
R. C. Smith ◽  
N. M. Moussa ◽  
G. E. Hawkins
Keyword(s):  
Escherichia Coli ◽  
Nucleic Acids ◽  
Trichloroacetic Acid ◽  
Soluble Fraction ◽  
Adenosine Monophosphate ◽  
Mixed Cultures ◽  
Guanosine Monophosphate ◽  
Rumen Bacteria ◽  
Rna And Dna

1.Escherichia coliand mixed cultures of rumen bacteria were grown with [8-14C]adenine to label their nucleic acids specifically.2. The labelled bacteria were injected into the rumen of sheep and the radioactivity incorporated into tissue nucleic acids and that excreted in the urine and faeces was determined.3. The radioactivity was present in the cold trichloroacetic acid-soluble fraction and the RNA and DNA fractions of all tissues examined. Liver, kidney, spleen, and blood had the highest levels of radioactivity.4. The radioactivity of the RNA was present only in adenosine monophosphate and guanosine monophosphate.

Inhibition of the induced synthesis of protocatechuate oxygenase by o-nitrobenzoic acid

1970 ◽  
Vol 16 (7) ◽  
pp. 609-614
Author(s):  
Karen F. Montgomery ◽  
Norman N. Durham
Keyword(s):  
Escherichia Coli ◽  
Amino Acids ◽  
Protein Synthesis ◽  
Trichloroacetic Acid ◽  
Protocatechuic Acid ◽  
Viable Cell ◽  
Insoluble Fraction ◽  
Nitrobenzoic Acid ◽  
Cell Counts ◽  
Oxygenase Activity

The synthesis of protocatechuate oxygenase (EC. 1.13.1.3), an inducible enzyme, by Pseudomonas fluorescens was inhibited by o-nitrobenzoic acid. The inhibitor did not alter the oxygenase activity of induced cells. Viable cell counts indicated that o-nitrobenzoic acid, in the concentrations used in these experiments, did not kill the cells. The inhibitor decreased the incorporation of L-tryptophan-14C and DL-glutamic-14C acid into the hot trichloroacetic acid insoluble fraction of the cell, but had no effect on the uptake of either radioactive amino acids or the inducer, protocatechuic acid. The synthesis of β-galactosidase by Escherichia coli was also inhibited by o-nitrobenzoic acid. The results establish that one site of o-nitrobenzoic acid inhibition is associated with protein synthesis in the cell.

scholarly journals Structure and expression of the alkA gene of Escherichia coli involved in adaptive response to alkylating agents.

1984 ◽  
Vol 259 (22) ◽  
pp. 13730-13736 ◽  
Author(s):  
Y Nakabeppu ◽  
T Miyata ◽  
H Kondo ◽  
S Iwanaga ◽  
M Sekiguchi
Keyword(s):  
Escherichia Coli ◽  
Adaptive Response ◽  
Alkylating Agents
Sign in / Sign up

Export Citation Format

Share Document