scholarly journals Isolation and characterization of an Escherichia coli strain exhibiting partial tolerance to quinolones.

1989 ◽  
Vol 33 (5) ◽  
pp. 705-709 ◽  
Author(s):  
J S Wolfson ◽  
D C Hooper ◽  
D J Shih ◽  
G L McHugh ◽  
M N Swartz
Keyword(s):  
Escherichia Coli ◽  
Coli Strain ◽  
Isolation And Characterization

scholarly journals Isolation and Characterization of a PEG-degrading and Mo-reducing Escherichia coli strain Amr-13 in soils from Egypt

2021 ◽  
Vol 9 (2) ◽  
pp. 23-29
Author(s):  
Nubli Shuhaimi ◽  
M. Abd AbdEl-Mongy ◽  
N.A. Shamaan ◽  
Chaing Hin Lee ◽  
M.A. Syed ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Growth Parameters ◽  
Sodium Molybdate ◽  
Gompertz Model ◽  
Coli Strain ◽  
Molybdenum Blue ◽  
Isolation And Characterization ◽  
Specific Growth Rates ◽  
Peg 600

Molybdenum is a pollutant that shows toxicity to spermatogenesis while polyethylene glycols (PEG) are used predominantly in detergents. The pollution of molybdenum and PEGs are reported worldwide. We have isolated ten molybdenum-reducing bacterial isolates from soil that can reduce molybdenum (sodium molybdate) into the colloidal molybdenum blue (Mo-blue). The screening of these isolates for PEG-degrading ability showed that one isolate was capable to utilize PEG 200, 300 and 600 for optimal conditions were pHs between 5.5 and 8.0, temperatures between 30 and 37 oC, phosphate at 5 mM, molybdate between 10 and 30 mM, and glucose as the electron donor. Biochemical analysis of the bacterium identifies it as Escherichia coli strain Amr-13. Growth was best supported by all PEGs at concentrations of between 600 and 1,000 mg/L. A complete degradation for PEG 200 and PEG 300 at 1,000 mg/L was observed on day four and five, respectively, while nearly 90% of PEG 600 was degraded on day six. The growth of this bacterium on these PEGs was modelled using the modified Gompertz model, and produced growth parameters values, which were maximum specific growth rates of 1.51, 1.45 and 1.18 d-1 and lag periods of 0.53, 0.87 and 1.02 day for PEG 200, PEG 300 and PEG 600, respectively. PEG 200 was the most preferred substrate for this bacterium, while PEG 600 was the least preferred.

Isolation And Characterization Of A Cdna Clone Coding For α1-Antitrypsin

1981 ◽  
Author(s):  
K Kurachi ◽  
K Chandra ◽  
S L C Woo ◽  
E W Davie
Keyword(s):  
Escherichia Coli ◽  
Cdna Clone ◽  
Coli Strain ◽  
Base Pairs ◽  
Isolation And Characterization ◽  
Pbr322 Dna ◽  
Free Translation ◽  
Alpha1 Antitrypsin ◽  
Carboxyl Terminal

Poly(A)-RNA enriched for α1-antitrypsin was isolated by specific immunoprecipitation of baboon liver polysomes. Alpha1-antitrypsin consisted of greater than 90% of the cell-free translation products of this mRNA. A doublestranded cDNA was synthesized by using reverse transcriptase and made blunt-ended with nuclease S1. After tailing with dCTP and terminal transferase, the double-stranded cDNA was annealed to pBR322 DNA. The latter DNA had been cleaved previously at the single Pst I site and similarly tailed with dGTP. The resulting plasmids were used to transform Escherichia coli strain RR1. Clones that hybridized to 32P-labeled cDNA synthesized from the α1-antitrypsin-enriched mRNA were then identified. The recombinants containing baboon cDNA inserts were further screened by a solution hybridization assay with [3H]cDNA synthesized from the enriched mRNA. The cDNA inserts from the positive clones were then sequenced to identify clones containing α1-antitrypsin. One insert, designated pBaαA1, was found to code for the carboxyl-terminal region of α1-antitrypsin. It also contained a noncoding region of 76 base pairs and a poly(A) tail of 60 base pairs.

Isolation and characterization of catabolite repression-resistant mutants of Escherichia coli

1977 ◽  
Vol 23 (10) ◽  
pp. 1384-1393 ◽  
Author(s):  
Glen D. Armstrong ◽  
Hiroshi Yamazaki
Keyword(s):  
Escherichia Coli ◽  
Catabolite Repression ◽  
Coli Strain ◽  
Wild Type ◽  
Phosphotransferase System ◽  
E Coli ◽  
Isolation And Characterization ◽  
In The Wild ◽  
Resistant Mutants

A method has been developed for the isolation of Escherichia coli mutants which are resistant to catabolite repression. The method is based on the fact that a mixture of glucose and gluconate inhibits the development of chemotactic motility in the wild type, but not in the mutants. A motile E. coli strain was mutagenized and grown in glucose and gluconate. Mutants which were able to swim into a tube containing a chemotactic attractant (aspartic acid) were isolated. Most of these mutants were able to produce β-galactosidase in the presence of glucose and gluconate and were normal in their ability to degrade adenosine 3′,5′-cyclic monophosphate. Some of these mutants were defective in the glucose phosphotransferase system.

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