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.

Lethal and mutagenic action of 3200–4000 Å light

1968 ◽  
Vol 14 (6) ◽  
pp. 727-735 ◽  
Author(s):  
S. J. Webb ◽  
C. C. Tai
Keyword(s):  
Escherichia Coli ◽  
Relative Humidity ◽  
Ultraviolet Light ◽  
Deoxyribonucleic Acid ◽  
Auxotrophic Mutant ◽  
Mutagenic Action ◽  
Black Light ◽  
Hydrolysis Of ◽  
Escherichia Coli B

Cells of a thymine-requiring auxotrophic mutant of Escherichia coli B have been irradiated with 2537 Å light (ultraviolet) and 3200–4000 Å light (black light) while being held in aerosols of various relative humidity (R.H.) levels. When cells were held in aerosols of 70% R.H. or lower they became susceptible to damage by black light and much of this damage could be prevented by the compound myo-inositol. The damage inflicted on cells by black light was not photorepairable by the usual methods, suggesting that the lesions produced are different from those produced by ultraviolet light. In addition, the ability of cells to undergo photorepair after irradiation with 2537 Å light was found to decrease rapidly when the cells were irradiated in a dry or near-dry state, indicating that the lesions produced under these conditions are different from those produced in wet cells.Sensitization of the cells to both kinds of radiations by the presence of bromodeoxyuridine (BUDR) in their deoxyribonucleic acid was apparent only when the cells were irradiated in a wet or semidry state, suggesting that sensitization involves a photostimulated hydrolysis of BUDR. Black light was found to be more mutagenic to cells held in a semidried state than was 2537 Å light. It is concluded that the irradiation of cells with 2537 Å light or with black light when they are in the dry state produces a lesion which is non-photorepairable and which is both lethal and mutagenic.

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.

scholarly journals The Deoxyribonucleic Acid Modification and Restriction Enzymes of Escherichia coli B

1972 ◽  
Vol 247 (19) ◽  
pp. 6176-6182
Author(s):  
James A. Lautenberger ◽  
Stuart Linn
Keyword(s):  
Escherichia Coli ◽  
Deoxyribonucleic Acid ◽  
Restriction Enzymes ◽  
Acid Modification ◽  
Escherichia Coli B

scholarly journals The Deoxyribonucleic Acid Modification and Restriction Enzymes of Escherichia coli B

1972 ◽  
Vol 247 (19) ◽  
pp. 6183-6191 ◽  
Author(s):  
Barnet Eskin ◽  
Stuart Linn
Keyword(s):  
Escherichia Coli ◽  
Deoxyribonucleic Acid ◽  
Restriction Enzymes ◽  
Acid Modification ◽  
Escherichia Coli B

scholarly journals Escherichia coli amino acid auxotrophic expression host strains for investigating protein structure-function relationships

2020 ◽  
Author(s):  
Toshio Iwasaki ◽  
Yoshiharu Miyajima-Nakano ◽  
Risako Fukazawa ◽  
Myat T Lin ◽  
Shin-Ichi Matsushita ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Amino Acids ◽  
Protein Structure ◽  
Amino Acid ◽  
Structure Function ◽  
Growth Medium ◽  
Isotope Labeling ◽  
Water Soluble ◽  
Expression Host ◽  
Host Strains

Abstract A set of C43(DE3) and BL21(DE3) Escherichia coli host strains that are auxotrophic for various amino acids is briefly reviewed. These strains require the addition of a defined set of one or more amino acids in the growth medium, and have been specifically designed for overproduction of membrane or water-soluble proteins selectively labeled with stable isotopes such as 2H, 13C and 15N. The strains described here are available for use and have been deposited into public strain banks. Although they cannot fully eliminate the possibility of isotope dilution and mixing, metabolic scrambling of the different amino acid types can be minimized through a careful consideration of the bacterial metabolic pathways. The use of a suitable auxotrophic expression host strain with an appropriately isotopically labeled growth medium ensures high levels of isotope labeling efficiency as well as selectivity for providing deeper insight into protein structure-function relationships.

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 Different Cellular Origins and Functions of Extracellular Proteins from Escherichia coli O157:H7 and O104:H4 as Determined by Comparative Proteomic Analysis

2016 ◽  
Vol 82 (14) ◽  
pp. 4371-4378 ◽  
Author(s):  
Nazrul Islam ◽  
Attila Nagy ◽  
Wesley M. Garrett ◽  
Dan Shelton ◽  
Bret Cooper ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Growth Medium ◽  
Foodborne Pathogen ◽  
The United States ◽  
Extracellular Proteins ◽  
Growth Media ◽  
Environmental Matrices ◽  
Content Type ◽  
E Coli ◽  
Relative Abundances

ABSTRACTExtracellular proteins play important roles in bacterial interactions with the environmental matrices. In this study, we examined the extracellular proteins fromEscherichia coliO157:H7 and O104:H4 by tandem mass spectrometry. We identified 500 and 859 proteins from the growth media ofE. coliO157:H7 and O104:H4, respectively, including 371 proteins common to both strains. Among proteins that were considered specific toE. coliO157:H7 or present at higher relative abundances in O157:H7 medium, most (57 of 65) had secretion signal sequences in their encoding genes. Noticeably, the proteins included locus of enterocyte effacement (LEE) virulence factors, proteins required for peptidyl-lipoprotein accumulation, and proteins involved in iron scavenging. In contrast, a much smaller proportion of proteins (37 of 150) that were considered specific to O104:H4 or presented at higher relative abundances in O104:H4 medium had signals targeting them for secretion. These proteins included Shiga toxin 2 subunit B and O104:H4 signature proteins, including AAF/1 major fimbrial subunit and serine protease autotransporters. Most of the abundant proteins from the growth medium ofE. coliO104:H4 were annotated as having functions in the cytoplasm. We provide evidence that the extensive presence of cytoplasmic proteins inE. coliO104:H4 growth medium was due to biological processes independent of cell lysis, indicating alternative mechanisms for this potent pathogen releasing cytoplasmic contents into the growth milieu, which could play a role in interaction with the environmental matrices, such as pathogenesis and biofilm formation.IMPORTANCEIn this study, we compared the extracellular proteins from two of the most prominent foodborne pathogenicE. coliorganisms that have caused severe outbreaks in the United States and in Europe.E. coliO157:H7 is a well-studied Shiga toxigenic foodborne pathogen of the enterohemorrhagic pathotype that has caused numerous outbreaks associated with various contaminated foods worldwide.E. coliO104:H4 is a newly emerged Shiga toxigenic foodborne pathogen of the enteroaggregative pathotype that gained notoriety for causing one of the most deadly foodborne outbreaks in Europe in 2011. Comparison of proteins in the growth medium revealed significant differences in the compositions of the extracellular proteins for these two pathogens. These differences may provide valuable information regarding the cellular responses of these pathogens to their environment, including cell survival and pathogenesis.

scholarly journals Comparation Between Mac conkey and Coconut Water Medium as a Growth Medium for Escherichia coli

2021 ◽  
Vol 3 (1) ◽  
pp. 19-25
Author(s):  
Endah Prayekti ◽  
Suliati Suliati ◽  
Dwi Agustin Wulandari
Keyword(s):  
Escherichia Coli ◽  
Growth Medium ◽  
Coconut Water ◽  
Growth Media ◽  
Water Medium ◽  
E Coli ◽  
Commercial Media ◽  
Randomized Design ◽  
Significant Difference ◽  
Water Media

Escherichia coli is the bacteria that can cause diarrhea in humans and often used as a parameter of stool environmental pollution. Culture of E. coli from the sample often requires Mac Conkey as commercial media which is able to distinguish it from other bacteria in the Enterobacteriaceae group. Commercial media such as Mac Conkey certainly has a price that is quite expensive because of its ability as a growth medium for Enterobacteriaceae. Therefore, in the study tested natural ingredients that can be used for growth media, such as coconut water. The purpose of this study was to compare the ability of Mac Conkey media and coconut water to support the growth of E. coli. This research is an experimental study with a completely randomized design. The concentration of coconut water tested was 0%, 20%, 40%, 60%, 80%, and 100%. The results showed that at the concentration of coconut water 20% to 60% the number of E. coli colonies on coconut water media was slightly below the Mac Conkey Agar media, while in coconut water a concentration of 80% showed a greater number of colonies than Mac Conkey. The Mann Whitney test showed a significant difference between the number of colonies on 80% coconut water media and Mac Conkey Agar, which was equal to 0.004 (p < 0.05). Based on these results, coconut water has the potential to be used as a growth medium for E. coli.

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