THE UTILIZATION OF ETHANOL FOR BIOSYNTHESIS IN ESCHERICHIA COLI

1958 ◽  
Vol 36 (8) ◽  
pp. 839-845 ◽  
Author(s):  
R. P. de Leon ◽  
E. H. Creaser
Keyword(s):  
Escherichia Coli ◽  
Nucleic Acid ◽  
Protein Fractions ◽  
Biosynthetic Pathways ◽  
Acid Fraction ◽  
E Coli ◽  
Deoxyribose Nucleic Acid ◽  
Cell Components

Radioactivity from 1-C14-ethanol was incorporated into the macromolecular components of Escherichia coli when this organism was grown on a synthetic glucose–salts medium. No significant incorporation was observed with mammalian tissues.Incorporation was greater in E. coli cells growing anaerobically than in non-growing or aerobically growing cells. The addition of sodium fumarate increased the incorporation in anaerobically growing cells approximately threefold.Over 90% of the incorporated radioactivity was found in the lipid and protein fractions of the cell, only a small amount being detectable in the nucleic acid fraction. The distribution of radioactivity among the various cell components was such that it appeared that ethanol was utilized by the same biosynthetic pathways as acetate. No evidence could be found to support the view that ethanol carbon was incorporated into deoxyribose of the deoxyribose nucleic acid (DNA) via acetaldehyde.

THE UTILIZATION OF ETHANOL FOR BIOSYNTHESIS IN ESCHERICHIA COLI

1958 ◽  
Vol 36 (1) ◽  
pp. 839-845 ◽  
Author(s):  
R. P. de Leon ◽  
E. H. Creaser
Keyword(s):  
Escherichia Coli ◽  
Nucleic Acid ◽  
Protein Fractions ◽  
Biosynthetic Pathways ◽  
Acid Fraction ◽  
E Coli ◽  
Deoxyribose Nucleic Acid ◽  
Cell Components

Radioactivity from 1-C14-ethanol was incorporated into the macromolecular components of Escherichia coli when this organism was grown on a synthetic glucose–salts medium. No significant incorporation was observed with mammalian tissues.Incorporation was greater in E. coli cells growing anaerobically than in non-growing or aerobically growing cells. The addition of sodium fumarate increased the incorporation in anaerobically growing cells approximately threefold.Over 90% of the incorporated radioactivity was found in the lipid and protein fractions of the cell, only a small amount being detectable in the nucleic acid fraction. The distribution of radioactivity among the various cell components was such that it appeared that ethanol was utilized by the same biosynthetic pathways as acetate. No evidence could be found to support the view that ethanol carbon was incorporated into deoxyribose of the deoxyribose nucleic acid (DNA) via acetaldehyde.

Combined Effect of Hop Resins and Sodium Hexametaphosphate against Certain Strains of Escherichia coli

2000 ◽  
Vol 63 (6) ◽  
pp. 735-740 ◽  
Author(s):  
TADASHI FUKAO ◽  
HARUMICHI SAWADA ◽  
YOSHIYUKI OHTA
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Activity ◽  
Food Systems ◽  
Combined Effect ◽  
Sodium Hexametaphosphate ◽  
Lag Phase ◽  
Phase Growth ◽  
E Coli ◽  
Cell Components ◽  
Strong Antimicrobial Activity

The combined antimicrobial effects of hop resins with sodium hexametaphosphate, glycerol monocaprate, and lysozyme were investigated aiming to make an effective agent against Escherichia coli. When they are used separately, the antimicrobial activity against E. coli was minimal. However, the combination of hop resins with sodium hexametaphosphate exhibited strong antimicrobial activity against E. coli, but no effect was found in combinations of hop resins with the other agents. The activity was strongest when the combination was added at the beginning of growth of the bacteria, resulting in a prolonged lag phase. However, when the antimicrobials were added during the log phase, growth was depressed considerably. By addition of these materials, cell components with absorbance near 260 nm were leaked out. This possibly may have resulted from damage to the cell membranes of the bacteria. The combined effect was also detected in model food systems such as mashed potatos. The use of hop resins and sodium hexametaphosphate in combination may thus be useful for controlling E. coli.

scholarly journals Detection of Escherichia coli O157 by Peptide Nucleic Acid FluorescenceIn SituHybridization (PNA-FISH) and Comparison to a Standard Culture Method

2013 ◽  
Vol 79 (20) ◽  
pp. 6293-6300 ◽  
Author(s):  
C. Almeida ◽  
J. M. Sousa ◽  
R. Rocha ◽  
L. Cerqueira ◽  
S. Fanning ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Nucleic Acid ◽  
Peptide Nucleic Acid ◽  
Food Samples ◽  
High Morbidity ◽  
Content Type ◽  
E Coli ◽  
Fish Method ◽  
The World ◽  
Pna Fish

ABSTRACTDespite the emergence of non-O157 Shiga toxin-producingEscherichia coli(STEC) infections,E. coliserotype O157 is still the most commonly identified STEC in the world. It causes high morbidity and mortality and has been responsible for a number of outbreaks in many parts of the world. Various methods have been developed to detect this particular serotype, but standard bacteriological methods remain the gold standard. Here, we propose a new peptide nucleic acid fluorescencein situhybridization (PNA-FISH) method for the rapid detection ofE. coliO157. Testing on 54 representative strains showed that the PNA probe is highly sensitive and specific toE. coliO157. The method then was optimized for detection in food samples. Ground beef and unpasteurized milk samples were artificially contaminated withE. coliO157 concentrations ranging from 1 × 10−2to 1 × 102CFU per 25 g or ml of food. Samples were then preenriched and analyzed by both the traditional bacteriological method (ISO 16654:2001) and PNA-FISH. The PNA-FISH method performed well in both types of food matrices with a detection limit of 1 CFU/25 g or ml of food samples. Tests on 60 food samples have shown a specificity value of 100% (95% confidence interval [CI], 82.83 to 100), a sensitivity of 97.22% (95% CI, 83.79 to 99.85%), and an accuracy of 98.33% (CI 95%, 83.41 to 99.91%). Results indicate that PNA-FISH performed as well as the traditional culture methods and can reduce the diagnosis time to 1 day.

Effect of Heat Shock and Incubation Atmosphere on Injury and Recovery of Escherichia coli O157:H7

1993 ◽  
Vol 56 (7) ◽  
pp. 568-572 ◽  
Author(s):  
ELSA A. MURANO ◽  
MERLE D. PIERSON
Keyword(s):  
Escherichia Coli ◽  
Heat Treatment ◽  
Heat Shock ◽  
Escherichia Coli O157 ◽  
Toxic Substances ◽  
Anaerobic Conditions ◽  
E Coli ◽  
Heat Treated ◽  
Shock Response ◽  
Cell Components

Escherichia coli serotype O157:H7 cells were grown at 30°C for 6 h and subjected to a heat stress, or heat shock, at 42°C for 5 min. Heat-shocked and nonheat-shocked controls were heat treated at 55°C for up to 60 min. The number of injured cells was significantly higher in heat-shocked cells than in controls, and the rate of release of cell components was higher in heat-shocked cells. Anaerobic plating resulted in higher recovery of injured cells, when compared with aerobic plating, regardless of whether the cells were heat shocked or not. In addition, heat shocking resulted in lower catalase and superoxide dismutase activities when compared with controls. It also resulted in greater survivability after exposure to hydrogen peroxide, suggesting that heat shocking somehow enables the cells to survive exposure to toxic substances in addition to heat. The heat-shock response, coupled with anaerobic conditions, increased the ability of E. coli O157:H7 cells to recover after a heat treatment. Thus, heat shock did not afford protection to the cells against injury, but rather enhanced their ability to recover during storage.

scholarly journals Engineering Escherichia coli coculture systems for the production of biochemical products

2015 ◽  
Vol 112 (27) ◽  
pp. 8266-8271 ◽  
Author(s):  
Haoran Zhang ◽  
Brian Pereira ◽  
Zhengjun Li ◽  
Gregory Stephanopoulos
Keyword(s):  
Escherichia Coli ◽  
Scale Up ◽  
Microbial Consortia ◽  
Biosynthetic Pathways ◽  
Muconic Acid ◽  
E Coli ◽  
Sugar Mixture ◽  
Low Efficiency ◽  
Valuable Compounds ◽  
High Level

Engineering microbial consortia to express complex biosynthetic pathways efficiently for the production of valuable compounds is a promising approach for metabolic engineering and synthetic biology. Here, we report the design, optimization, and scale-up of an Escherichia coli-E. coli coculture that successfully overcomes fundamental microbial production limitations, such as high-level intermediate secretion and low-efficiency sugar mixture utilization. For the production of the important chemical cis,cis-muconic acid, we show that the coculture approach achieves a production yield of 0.35 g/g from a glucose/xylose mixture, which is significantly higher than reported in previous reports. By efficiently producing another compound, 4-hydroxybenzoic acid, we also demonstrate that the approach is generally applicable for biosynthesis of other important industrial products.

The Conservation of Amino Acids in the N-Terminal Position of Ribosomal and Cytosol Proteins from Escherichia coli, Bacillus stearothermophilus, and Halobacterium cutirubrum

1975 ◽  
Vol 53 (12) ◽  
pp. 1323-1327 ◽  
Author(s):  
Alastair T. Matheson ◽  
Makoto Yaguchi ◽  
Louis P. Visentin
Keyword(s):  
Escherichia Coli ◽  
Amino Acids ◽  
Ribosomal Protein ◽  
Ribosomal Proteins ◽  
Bacillus Stearothermophilus ◽  
Protein Fractions ◽  
Extreme Halophile ◽  
Terminal Position ◽  
E Coli ◽  
Terminal Residue

Alanine, methionine, and serine are the predominant N-terminal residues in the cytosol and ribosomal protein fractions from the thermophile Bacillus stearothermophilus and the extreme halophile Halobacterium cutirubrum, a similar situation to that previously found in Escherichia coli. In all three bacteria the N-terminal residues of the 30S ribosomal proteins are mainly alanine [Formula: see text] methionine > serine whereas in the 50S ribosomal proteins from E. coli and B. stearothermophilus the predominant residues are methionine > alanine > serine suggesting conservation of specific N-terminal residues in these ribosomal proteins. However, the 50S ribosomal proteins from H. cutirubrum showed serine as the major N-terminal residue.

scholarly journals The biosynthetic pathway of ubiquinone contributes to pathogenicity of Francisella

2021 ◽  
Author(s):  
Katayoun Kazemzadeh ◽  
Mahmoud Hajj Chehade ◽  
Hourdoir Gautier ◽  
Brunet Camille ◽  
Yvan Caspar ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Animal Model ◽  
Biosynthetic Pathway ◽  
Galleria Mellonella ◽  
Hydroxybenzoic Acid ◽  
Strictly Aerobic ◽  
Biosynthetic Pathways ◽  
Francisella Novicida ◽  
E Coli ◽  
Respiratory Medium

Francisella tularensis is the causative agent of tularemia. Because of its extreme infectivity and high mortality rate, this pathogen was classified as a biothreat agent. Francisella spp are strict aerobe and ubiquinone (UQ) has been previously identified in these bacteria. While the UQ biosynthetic pathways were extensively studied in Escherichia coli allowing the identification of fifteen Ubi-proteins to date, little is known about Francisella spp. In this study, and using Francisella novicida as a surrogate organism, we first identified UQ8 as the major quinone found in the membranes of this bacterium. Then, we characterized the UQ biosynthetic pathway in F. novicida using a combination of bioinformatics, genetics and biochemical approaches. Our analysis disclosed the presence in Francisella of ten putative Ubi-proteins and we confirmed eight of them by heterologous complementation in E. coli. The UQ biosynthetic pathways from F. novicida and E. coli share a similar pattern. However, differences were highlighted: the decarboxylase remains unidentified in Francisella spp and homologs of the Ubi-proteins involved in the O2-independent UQ pathway are not present. This is in agreement with the strictly aerobic niche of this bacterium. Then, via two approaches, i.e. the use of an inhibitor (3-amino-4-hydroxybenzoic acid) and a transposon mutant, which both strongly impair the synthesis of UQ, we demonstrated that UQ is essential for the growth of F. novicida in a respiratory medium and contributes to its pathogenicity in Galleria mellonella used as an alternative animal model.

scholarly journals Metabolic engineering of Escherichia coli for optimized biosynthesis of nicotinamide mononucleotide, a noncanonical redox cofactor

2020 ◽  
Author(s):  
William B. Black ◽  
Derek Aspacio ◽  
Danielle Bever ◽  
Edward King ◽  
Linyue Zhang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Gene Disruption ◽  
Fold Increase ◽  
Economic Viability ◽  
Biosynthetic Pathways ◽  
Nicotinamide Phosphoribosyltransferase ◽  
E Coli ◽  
Nicotinamide Mononucleotide ◽  
Screening Platform ◽  
Future Work

AbstractBackgroundNoncanonical redox cofactors are emerging as important tools in cell-free biosynthesis to increase the economic viability, to enable exquisite control, and to expand the range of chemistries accessible. However, these noncanonical redox cofactors need to be biologically synthesized to achieve full integration with renewable biomanufacturing processes.ResultsIn this work, we engineered Escherichia coli cells to biosynthesize the noncanonical cofactor nicotinamide mononucleotide (NMN+), which has been efficiently used in cell-free biosynthesis. First, we developed a growth-based screening platform to identify effective NMN+ biosynthetic pathways in E. coli. Second, we explored various pathway combinations and host gene disruption to achieve an intracellular level of ~1.5 mM NMN+, a 130-fold increase over the cell’s basal level, in the best strain, which features a previously uncharacterized nicotinamide phosphoribosyltransferase (NadV) from Ralstonia solanacearum. Last, we revealed mechanisms through which NMN+ accumulation impacts E. coli cell fitness, which sheds light on future work aiming to improve the production of this noncanonical redox cofactor.ConclusionThese results further the understanding of effective production and integration of NMN+ into E. coli. This may enable the implementation of NMN+-directed biocatalysis without the need for exogenous cofactor supply.

scholarly journals Characterization of Primed Adaptation in the Escherichia coli type I-E CRISPR-Cas System

2020 ◽  
Author(s):  
Anne M. Stringer ◽  
Lauren A. Cooper ◽  
Sujatha Kadaba ◽  
Shailab Shrestha ◽  
Joseph T. Wade
Keyword(s):  
Escherichia Coli ◽  
Nucleic Acid ◽  
Genetic Locus ◽  
Type I ◽  
Cornell University ◽  
E Coli ◽  
Nucleic Acid Molecule ◽  
Bacterial Immune Systems ◽  
Insight Into

ABSTRACTCRISPR-Cas systems are bacterial immune systems that target invading nucleic acid. The hallmark of CRISPR-Cas systems is the CRISPR array, a genetic locus that includes short sequences known as “spacers”, that are derived from invading nucleic acid. Upon exposure to an invading nucleic acid molecule, bacteria/archaea with functional CRISPR-Cas systems can add new spacers to their CRISPR arrays in a process known as “adaptation”. In type I CRISPR-Cas systems, which represent the majority of CRISPR-Cas systems found in nature, adaptation can occur by two mechanisms: naïve and primed. Here, we show that, for the archetypal type I-E CRISPR-Cas system from Escherichia coli, primed adaptation occurs at least 1,000 times more efficiently than naïve adaptation. By initiating primed adaptation on the E. coli chromosome, we show that spacers can be acquired across distances of >100 kb from the initially targeted site, and we identify multiple factors that influence the efficiency with which sequences are acquired as new spacers. Thus, our data provide insight into the mechanism of primed adaptation.[This paper has been peer reviewed, with Ailong Ke (Cornell University) serving as the editor. Reviews and point-by-point response, and a marked-up version of the edited manuscript are provided as supplementary files.]

REGULATION OF ACETOHYDROXY ACID SYNTHETASE IN STREPTOMYCIN-DEPENDENT ESCHERICHIA COLI

1966 ◽  
Vol 44 (5) ◽  
pp. 599-606 ◽  
Author(s):  
W. J. Polglase
Keyword(s):  
Escherichia Coli ◽  
Minimal Medium ◽  
Specific Activity ◽  
Product Inhibition ◽  
Biosynthetic Pathways ◽  
Regulatory Effect ◽  
Antibiotic Concentration ◽  
E Coli ◽  
End Products ◽  
Glutamic Dehydrogenase

The formation of acetolactate from pyruvate by extracts of streptomycin-dependent Escherichia coli was inhibited, competitively, by L-valine, thus establishing the potential in the dependent mutant for regulation of the activity of acetohydroxy acid synthetase through end-product inhibition. Furthermore, the level of acetohydroxy acid synthetase was decreased in streptomycin-dependent E. coli by growth in minimal medium to which had been added the end products of the biosynthetic pathways initiated by this enzyme, thus establishing the potential in dependent cells for regulation of acetohydroxy acid synthetase through repression. In contrast, the specific activity of acetohydroxy acid synthetase in extracts of streptomycin-dependent E. coli increased in proportion to the concentration of antibiotic (dihydrostreptomycin) present in the medium during growth, thereby indicating a positive regulatory effect of dihydrostreptomycin on the formation of this enzyme. The formation of two enzymes used as monitors, glucokinase, and glutamic dehydrogenase, was not affected by variation in antibiotic concentration.

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