Increased hydrogen production by Escherichia coli strain HD701 in comparison with the wild-type parent strain MC4100

Escherichia coli strain 15-28 is a mutant with a defect in ribosome synthesis that leads to the accumulation of large amounts of ribonucleoprotein (“47S”) particles during exponential growth. These particles are precursors to 50S ribosomes, but are distinct from precursors detected by pulse-labelling of the parent strain and also from ribosome precursors that accumulate during inhibition of growth by CoC12. Either ribosome assembly in the mutant differs from that in the wild-type strain, or 47S particles represent a hitherto unstudied stage in the synthesis of 50S ribosomes.

Download Full-text

Sensitivity of normal and mutant strains of Escherichia coli to actinomycin-D

Canadian Journal of Microbiology ◽

10.1139/m72-139 ◽

1972 ◽

Vol 18 (6) ◽

pp. 909-915 ◽

Cited By ~ 4

Author(s):

A. P. Singh ◽

K.-J. Cheng ◽

J. W. Costerton ◽

E. S. Idziak ◽

J. M. Ingram

Keyword(s):

Escherichia Coli ◽

Cell Wall ◽

Wild Type Strain ◽

Actinomycin D ◽

Cytoplasmic Membrane ◽

Cell Envelope ◽

Coli Strain ◽

Wild Type ◽

Mutant Strains ◽

In The Wild

The site of the cell barrier to actinomycin-D uptake was studied using a wild-type Escherichia coli strain P and its cell envelope-defective filamentous mutants, strains 6γ and 12γ, both of which 'leak' β-galactosidase and alkaline phosphatase into the medium during growth indicating both membrane and cell-wall defects. Actinomycin-D entered the cells of these two mutant strains as evidenced by the inhibition of both 14C-uracil incorporation and synthesis of the induced β-galactosidase system. Under similar conditions, no inhibition occurred in the wild-type strain and its sucrose-lysozyme prepared spheroplasts. Actinomycin-D did, however, inhibit the above-mentioned systems in the wild-type sucrose-lysozyme spheroplasts prepared in the presence of 2 mM EDTA. The experimental data indicate that although the cell wall may act as a primary barrier or sieve to actinomycin-D, the cytoplasmic membrane should be considered the final and determinative barrier to this antibiotic.

Download Full-text

Effect offurmutation on acid-tolerance response and in vivo virulence of avian septicemicEscherichia coli

Canadian Journal of Microbiology ◽

10.1139/w02-042 ◽

2002 ◽

Vol 48 (5) ◽

pp. 458-462 ◽

Cited By ~ 10

Author(s):

Chengru Zhu ◽

Musangu Ngeleka ◽

Andrew A Potter ◽

Brenda J Allan

Keyword(s):

Parent Strain ◽

Acid Tolerance ◽

Wild Type ◽

Acid Tolerance Response ◽

E Coli ◽

Regulator Protein ◽

In The Wild ◽

Tolerance Response ◽

Wild Type Parent

The Fur (ferric uptake regulator) protein is a master regulator of iron metabolism in gram-negative bacteria. In the present study, the effect of a partial deletion of the fur gene on the acid-tolerance response and in vivo virulence of avian Escherichia coli was examined. The fur mutant was unable to trigger the acid-tolerance response as observed in the wild-type parent strain. However, the mutant was as virulent as the wild-type parent strain when tested in 1-day-old chickens by subcutaneous inoculation. These data indicate that the fur gene is involved in the acid-tolerance response but not involved in the virulence of E. coli, as detected by the ability to cause septicemia in our experimental infection.Key words: E. coli, fur, acid-tolerance response.

Download Full-text

Homologous recombination involving a large heterology in Escherichia coli.

Genetics ◽

10.1093/genetics/119.4.759 ◽

1988 ◽

Vol 119 (4) ◽

pp. 759-769

Author(s):

K Yamamoto ◽

N Takahashi ◽

H Yoshikura ◽

I Kobayashi

Keyword(s):

Escherichia Coli ◽

Gene Conversion ◽

Kanamycin Resistance ◽

Coli Strain ◽

The Other ◽

Reca Gene ◽

Inverted Repeats ◽

Crossing Over ◽

Wild Type ◽

Parental Allele

Abstract Recombination between two different deletion alleles of a gene (neo) for neomycin and kanamycin resistance was studied in an Escherichia coli sbcA- recB-C- strain. The two homologous regions were in an inverted orientation on the same plasmid molecule. Kanamycin-resistant plasmids were selected and analyzed. The rate of recombination to form kanamycin-resistant plasmids was decreased by mutations in the recE, recF and recJ genes, but was not decreased by a mutation in the recA gene. It was found that these plasmids often possessed one wild-type kanamycin-resistant allele (neo+) while the other neo allele was still in its original (deletion) form. Among kanamycin-resistant plasmids with one wild-type and one parental allele it was often found that the region between the inverted repeats had been flipped (turned around) with respect to sites outside the inverted repeats. These results were interpreted as follows. Gene conversion, analogous to gene conversion in eukaryotic meiosis, is responsible for a unidirectional transfer of information from one neo deletion allele to the other. The flipping of the region between the inverted repeats is interpreted as analogous to the crossing over associated with gene conversion in eukaryotic meiosis. In contrast with a rec+ strain, these products cannot be explained by two rounds of reciprocal crossing over involving a dimeric form as an intermediate. In the accompanying paper we present evidence that gene conversion by double-strand gap repair takes place in the same E. coli strain.

Download Full-text

Characterization of Hydrogen Production by Escherichia coli Wild-type and Mutants of Hydrogenases Utilizing Xylose as Fermentation Substrate

BioEnergy Research ◽

10.1007/s12155-019-10035-4 ◽

2019 ◽

Vol 12 (4) ◽

pp. 1033-1041 ◽

Cited By ~ 1

Author(s):

Anna Poladyan ◽

Armen Trchounian

Keyword(s):

Escherichia Coli ◽

Hydrogen Production ◽

Wild Type ◽

Fermentation Substrate

Download Full-text

Comparative genomic analyses ofMycoplasma synoviaevaccine strain MS-H and its wild-type parent strain 86079/7NS: implications for the identification of virulence factors and applications in diagnosis ofM. synoviae

Avian Pathology ◽

10.1080/03079457.2019.1637514 ◽

2019 ◽

Vol 48 (6) ◽

pp. 537-548 ◽

Cited By ~ 2

Author(s):

Ling Zhu ◽

Muhammad A. Shahid ◽

John Markham ◽

Glenn F. Browning ◽

Amir H. Noormohammadi ◽

...

Keyword(s):

Virulence Factors ◽

Parent Strain ◽

Comparative Genomic ◽

Wild Type ◽

Genomic Analyses ◽

Wild Type Parent

Download Full-text

PBP5, PBP6 and DacD play different roles in intrinsic β-lactam resistance of Escherichia coli

Microbiology ◽

10.1099/mic.0.046227-0 ◽

2011 ◽

Vol 157 (9) ◽

pp. 2702-2707 ◽

Cited By ~ 25

Author(s):

Sujoy Kumar Sarkar ◽

Mouparna Dutta ◽

Chiranjit Chowdhury ◽

Akash Kumar ◽

Anindya S. Ghosh

Keyword(s):

Escherichia Coli ◽

Amino Acid ◽

Parent Strain ◽

Amino Acid Identity ◽

Enzymic Activity ◽

Exponential Phase ◽

Wild Type ◽

Acid Identity ◽

Penicillin Binding Proteins ◽

E Coli

Escherichia coli PBP5, PBP6 and DacD, encoded by dacA, dacC and dacD, respectively, share substantial amino acid identity and together constitute ~50 % of the total penicillin-binding proteins of E. coli. PBP5 helps maintain intrinsic β-lactam resistance within the cell. To test if PBP6 and DacD play simlar roles, we deleted dacC and dacD individually, and dacC in combination with dacA, from E. coli 2443 and compared β-lactam sensitivity of the mutants and the parent strain. β-Lactam resistance was complemented by wild-type, but not dd-carboxypeptidase-deficient PBP5, confirming that enzymic activity of PBP5 is essential for β-lactam resistance. Deletion of dacC and expression of PBP6 during exponential or stationary phase did not alter β-lactam resistance of a dacA mutant. Expression of DacD during mid-exponential phase partially restored β-lactam resistance of the dacA mutant. Therefore, PBP5 dd-carboxypeptidase activity is essential for intrinsic β-lactam resistance of E. coli and DacD can partially compensate for PBP5 in this capacity, whereas PBP6 cannot.

Download Full-text