THE INFLUENCE OF TIME AND MEDIA CHANGES ON THE INDUCTION AND SUPPRESSION OF β-GALACTOSIDASE SYNTHESIS IN ESCHERICHIA COLI B

1967 ◽  
Vol 13 (3) ◽  
pp. 257-269
Author(s):  
S. J. Webb ◽  
Janet L. Walker
Keyword(s):  
Escherichia Coli ◽  
Amino Acids ◽  
Minimal Medium ◽  
Sole Source ◽  
Enzyme Synthesis ◽  
Induction Medium ◽  
Nucleic Acid Bases ◽  
Apparent Effect ◽  
Lag Period ◽  
Escherichia Coli B

When cells of Escherichia coli B were grown in a glucose – amino acid medium and then transferred to a minimal medium containing lactose or isopropyl-β-D-thiogalactopyranoside as a sole source of carbon, no induction of β-galactosidase occurred unless one or several amino acids were supplied. Of the amino acids tested, aspartic acid was the most effective and its ability to initiate the synthesis of the enzyme was increased by the addition of arginine. In the presence of these two, or all of the amino acids, there was a lag period of 10 min before enzyme synthesis occurred. The duration of the lag period was unaffected by the addition of nucleic acid bases or succinate to the induction medium. Succinate or glutamate partially inhibited the synthesis of the enzyme, whereas glucose, inositol, or chloramphenicol completely suppressed it. With the exception of that produced by chloramphenicol, inhibition was dependent on the time at which the inhibitor was added. If inhibitors were added after the 10-min lag period, they had no apparent effect until 45 min had elapsed. Cells transferred after 15 min from one induction medium to another displayed for 30 min the induction characteristics of the first medium. It appears that a process occurring during the early 15-min period determines the rate at which enzymes will be synthesized for the next 30 min and that the action of inhibitors is to prevent this process. The process seems to require intact DNA and amino acids and it is suggested that it determines the specificity and quantity of mRNA manufactured.

SOME OBSERVATIONS CONCERNING DNA AND β-GALACTOSIDASE SYNTHESIS IN ESCHERICHIA COLI B

1967 ◽  
Vol 13 (4) ◽  
pp. 377-388 ◽  
Author(s):  
S. J. Webb ◽  
J. Singh Bhorjee ◽  
Janet L. Walker ◽  
D. A. Rokosh
Keyword(s):  
Escherichia Coli ◽  
Dna Replication ◽  
Enzyme Synthesis ◽  
Induction Medium ◽  
Minute Period ◽  
Rate Characteristic ◽  
Two Stages ◽  
Escherichia Coli B

When starved cells of thymine-requiring Escherichia coli B were placed in a complete induction medium there was an initial lag of 10 minutes before measurable amounts of the enzyme were detected. Cells exposed for 15 minutes to one inducer and then given an alternative inducer continued to manufacture the enzyme for 60 minutes at a rate characteristic of the initial inducer. After this period, enzyme manufacture assumed the characteristics of the second inducer. Glucose or mitomycin was found to inhibit enzyme synthesis only when they were added during the first 10 minutes or 45- to 60-minute periods of induction. Chloramphenicol stopped enzyme synthesis at any stage of induction. The synthesis of DNA was found to occur in two stages and enzyme synthesis was prevented by glucose or mitomycin only if they were added to the cells during a 10-minute period which immediately preceded DNA replication. It is concluded that a gene can express itself only once, and change in expression requires the synthesis of new DNA.

THE INFLUENCE OF GROWTH MEDIA ON PROTEINS BOUND TO DNA AND THEIR POSSIBLE ROLE IN THE RESPONSE OF ESCHERICHIA COLI B TO ULTRAVIOLET LIGHT

1967 ◽  
Vol 13 (1) ◽  
pp. 57-68 ◽  
Author(s):  
S. J. Webb
Keyword(s):  
Escherichia Coli ◽  
Amino Acids ◽  
Ultraviolet Light ◽  
Growth Medium ◽  
Deoxyribonucleic Acid ◽  
Mutant Cell ◽  
Growth Media ◽  
Nucleic Acid Bases ◽  
Residual Protein ◽  
Escherichia Coli B

The deoxyribonucleic acid (DNA) from cells of Escherichia coli B, after rigorous extraction, was found to contain residual amounts of protein, the quantity of which was determined by the medium in which the cells were grown. The DNA of cells grown in a minimal salts medium contained from 10 to 15 times more protein than the DNA of cells grown in an enriched medium. The addition of amino acids, vitamins, or nucleic acid bases to the growth medium resulted in a decrease in the amount of residual protein and an increase in the sensitivity of the cells to ultraviolet light. Of the enrichments tested, the amino acids produced the greatest decrease in the quantity of residual proteins and the largest increase in sensitivity to ultraviolet. The type of mutant cell produced by ultraviolet irradiation was found to be strongly influenced by the ingredients of the growth medium. Few mutants were found after the irradiation of cells grown in the minimal salts medium but when the growth medium was enriched with amino acids, many mutants requiring amino acids appeared. Similarly the addition of vitamins or bases resulted in the production of vitamin-and base-requiring mutants. It is suggested that these residual proteins become attached to specific sites on the DNA during the operation of certain genes and this results in an increase in the ability of the DNA to withstand the damaging action of desiccation and ultraviolet light.

scholarly journals Modification by an R determinant for streptomycin of hissd phenotype in a mutant strain of Escherichia coli B

1968 ◽  
Vol 12 (2) ◽  
pp. 109-116 ◽  
Author(s):  
A. M. Molina ◽  
L. Calegari ◽  
G. Conte
Keyword(s):  
Escherichia Coli ◽  
Cell Membrane ◽  
Mutant Strain ◽  
Minimal Medium ◽  
Specific Requirement ◽  
Resistance Level ◽  
E Coli ◽  
Level Characteristic ◽  
Escherichia Coli B

When an R determinant for streptomycin is transferred into a conditionally streptomycin-dependent E. coli B mutant—which requires in minimal medium either histidine or streptomycin—the latter behaves like a histidineless strain. This phenotype modification shows that the repairing action of streptomycin is prevented. The specific requirement of the strain is not now replaced even by streptomycin concentrations up to 10000 µg/ml at which the conditionally streptomycin-dependent mutant could originally grow, and which are well beyond the resistance level characteristic of the R determinant itself. These data seem to suggest that a reduction in permeability of the cell membrane cannot be held responsible for the phenomenon observed.

Effect of ascorbate on oxygen uptake and growth of Escherichia coli B

1988 ◽  
Vol 34 (6) ◽  
pp. 822-824 ◽  
Author(s):  
Holly E. Richter ◽  
Jacek Switala ◽  
Peter C. Loewen
Keyword(s):  
Escherichia Coli ◽  
Oxygen Uptake ◽  
Electron Acceptor ◽  
Minimal Medium ◽  
Anaerobic Growth ◽  
Rich Medium ◽  
Terminal Electron Acceptor ◽  
Subsequent Change ◽  
Escherichia Coli B

The addition of ascorbate to aerobically growing cultures of Escherichia coli B caused only a short pause in growth and no subsequent change in the rate or extent of growth. The effect of ascorbate on oxygen uptake varied from inhibition in minimal medium to stimulation in rich medium. Cyanide-resistant growth and oxygen uptake were stimulated by ascorbate. Both the rate and extent of anaerobic growth were stimulated in proportion to the amount of ascorbate added when fumarate was the terminal electron acceptor. Ascorbate had no effect on any aspect of anaerobic growth in the absence of a terminal electron acceptor or in the presence of nitrate.

Propriétés physiques et chimiques des tryptophanases de cinq espèces d'Entérobactériaceae

1975 ◽  
Vol 21 (6) ◽  
pp. 828-833 ◽  
Author(s):  
C. Simard ◽  
A. Mardini ◽  
L. M. Bordeleau
Keyword(s):  
Escherichia Coli ◽  
Amino Acids ◽  
Molecular Weight ◽  
Sedimentation Coefficient ◽  
Species Differentiation ◽  
Proteus Vulgaris ◽  
Amino Acids Composition ◽  
Propriétés Physiques ◽  
Tryptophan Content ◽  
Escherichia Coli B

The molecular weight, sedimentation coefficient, and amino acids composition were determined on five tryptophanases (TPases) from Escherichia coli B and E. aurescens, Shigella alkalescens, and Proteus vulgaris and P. morganii. These TPases have identical sedimentation profile and coefficient (9.6 S), and the same molecular weight (220 000). Each enzyme is constituted of four identical subunits having a molecular weight of 55 000. The amino acids composition of these TPases is very similar, with the exception of P. morganii and P. vulgaris TPases which present significative variations in basic amino acids and tryptophan content. The species differentiation of the coli group cannot be made on their TPase characteristics only, contrary to P. morganii and P. vulgaris which can be differentiated between them and from the coli group. [Journal translation]

scholarly journals Utilization of Amino Acids as the Sole Source of Nitrogen by Escherichia coli No. 1

1958 ◽  
Vol 78 (2) ◽  
pp. 126-128 ◽  
Author(s):  
Tatsu Kawano
Keyword(s):  
Escherichia Coli ◽  
Amino Acids ◽  
Sole Source

scholarly journals Role of the sRNA GcvB in regulation of cycA in Escherichia coli

Microbiology ◽  
2009 ◽  
Vol 155 (1) ◽  
pp. 106-114 ◽  
Author(s):  
Sarah C. Pulvermacher ◽  
Lorraine T. Stauffer ◽  
George V. Stauffer
Keyword(s):  
Escherichia Coli ◽  
Amino Acids ◽  
Minimal Medium ◽  
Luria Bertani ◽  
Cell Physiology ◽  
Rt Pcr ◽  
Luria Bertani Broth ◽  
Increased Sensitivity ◽  
Transcriptional Fusions

In Escherichia coli, the gcvB gene encodes a small non-translated RNA that regulates several genes involved in transport of amino acids and peptides (including sstT, oppA and dppA). Microarray analysis identified cycA as an additional regulatory target of GcvB. The cycA gene encodes a permease for the transport of glycine, d-alanine, d-serine and d-cycloserine. RT-PCR confirmed that GcvB and the Hfq protein negatively regulate cycA mRNA in cells grown in Luria–Bertani broth. In addition, deletion of the gcvB gene resulted in increased sensitivity to d-cycloserine, consistent with increased expression of cycA. A cycA : : lacZ translational fusion confirmed that GcvB negatively regulates cycA expression in Luria–Bertani broth and that Hfq is required for the GcvB effect. GcvB had no effect on cycA : : lacZ expression in glucose minimal medium supplemented with glycine. However, Hfq still negatively regulated the fusion in the absence of GcvB. A set of transcriptional fusions of cycA to lacZ identified a sequence in cycA necessary for regulation by GcvB. Analysis of GcvB identified a region complementary to this region of cycA mRNA. However, mutations predicted to disrupt base-pairing between cycA mRNA and GcvB did not alter expression of cycA : : lacZ. A model for GcvB function in cell physiology is discussed.

THE EFFECT OF 3000–4000 Å LIGHT ON THE SYNTHESIS OF β-GALACTOSIDASE AND BACTERIOPHAGES BY ESCHERICHIA COLI B

1967 ◽  
Vol 13 (1) ◽  
pp. 69-79 ◽  
Author(s):  
S. J. Webb ◽  
J. Singh Bhorjee
Keyword(s):  
Escherichia Coli ◽  
Amino Acids ◽  
Dna Replication ◽  
Glutamic Acid ◽  
Strong Correlation ◽  
Sublethal Doses ◽  
Time Periods ◽  
Escherichia Coli B

The irradiation of Escherichia coli B with sublethal doses of 3000–4000 Å light prevented the microorganisms from manufacturing β-galactosidase and T2 and T7 coliphages. Inhibition occurred only if the cells were irradiated immediately after their contact with the inducer lactose or infection with T2 and T7 phages. If, before irradiation the cells were allowed to incubate for 15 min after the addition of lactose or the coliphages to the cells, little effect of the light was found. The uptake of uracil and amino acids by washed cells was more rapid in the first 15 min than during later time periods while thymine uptake did not begin until the first 15 min had elapsed. The 3000–4000 Å light inhibited the uptake of arginine and thymine but not uracil or glutamic acid. The addition of 5% inositol inhibited the synthesis of β-galactosidase and the uptake of14C-labelled metabolites. Since there was a strong correlation between the degree to which arginine and thymine uptakes were inhibited by the light or inositol, it appears that the production of a protein during the first 15 min is intimately connected with DNA replication and the synthesis of induced enzymes.

fusB is an allele of nadD, encoding nicotinate mononucleotide adenylyltransferase in Escherichia coli

Microbiology ◽  
2003 ◽  
Vol 149 (9) ◽  
pp. 2427-2433 ◽  
Author(s):  
Martin Stancek ◽  
Leif A. Isaksson ◽  
Monica Rydén-Aulin
Keyword(s):  
Escherichia Coli ◽  
Amino Acids ◽  
Temperature Sensitivity ◽  
Minimal Medium ◽  
Synthetic Medium ◽  
Normal Growth ◽  
Temperature Sensitive ◽  
Permissive Temperature ◽  
Atp Binding Site ◽  
Pleiotropic Phenotype

Isolation of the temperature-sensitive Escherichia coli mutant 72c has been described previously. The mutant allele was named fusB and causes a pleiotropic phenotype, the most striking features of which, besides temperature sensitivity, are the inability to grow on synthetic medium and supersensitivity to trimethoprim, an antibiotic that inhibits the C1 metabolism. This work shows that the fusB mutation is a frameshift mutation in the nadD gene that encodes nicotinate mononucleotide adenylyltransferase. The frameshift leads to a change of the last 10 amino acids and an addition of 17 amino acids. This lesion, renamed nadD72, leads to very little NAD+ and NADPH synthesis at the permissive temperature and essentially no synthesis at the non-permissive temperature. As a comparison, a new mutation in the nadD gene, with an amino acid change in the ATP-binding site, has been isolated. Its NAD+ synthesis is decreased at 30 °C but the level is still sufficient to support normal growth. At 42 °C, NAD+ synthesis is reduced further, which leads to temperature sensitivity on minimal medium. This mutation was designated nadD74. Thus, a small decrease in NAD+ levels affects ability to grow on minimal medium at 42 °C, while a large decrease leads to a more pleiotropic phenotype.

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