A spontaneous fluoroquinolone-resistant mutant (STM1) was isolated from its parent Salmonella enterica serovar Typhi (S. Typhi) clinical isolate. Unlike its parent isolate, this mutant has selective resistance to fluoroquinolones without any change in its sensitivity to various other antibiotics. DNA gyrase assays revealed that the fluoroquinolone resistance phenotype of the STM1 mutant did not...

To facilitate the biodegradation of diesel oil, an oil biodegradation bacterial consortium was constructed. The alkane hydroxylase (alkB) gene of Pseudomonas putida GPo1 was constructed in a pCom8 expression vector, and the pCom8-GPo1 alkB plasmid was transformed into Escherichia coli DH5α. The AlkB protein was expressed by diesel oil induction and detected through SDS-polyacrylamide gel electr...

BACKGROUND Plasmid transfer among bacteria provides a means for dissemination of resistance. Plasmid Analysis has made it possible to track plasmids that induce resistance in bacterial population. OBJECTIVES To screen the presence of herb-resistance plasmid in Escherichia coli strains and determine the transferability of this resistance plasmid directly from E. coli to the Gram-positive, Stap...

The genomes of many strains of Escherichia coli have been sequenced, as this organism is a classic model bacterium. Here, we report the genome sequence of Escherichia coli DH5α, which is resistant to a T4 bacteriophage (CCTCC AB 2015375), while its other homologous E. coli strains, such as E. coli BL21, DH10B, and MG1655, are not resistant to phage invasions. Thus, understanding of the genome o...

conclusions: e. coli herb-resistance plasmid can replicate and be expressed in s. aureus. results: the identified 45 kb herb-resistance plasmid could be transferred from e. coli cp9 isolates to e. coli dh5α. as a consequence e. coli dh5α transconjugant mic increased from 0.0125 g/ml to 0.25 g/ml. the plasmid was easily transferred from e. coli cp9 strain to s. aureus rn450rf with a mean transfe...

Today, efforts go towards the replacement of chemical surfactants by natural biological biosurfactants (biosurfactant), as these materials are not carcinogenic and highly compatibile with the environment. One of the main classes of biosurfactants is rhamnose containing glycolipid biosurfactant (rhamnolipids). This type of biosurfactants can be applied in many industries such as oil industry, ph...

Original Article Alcaligeneseutrophus H16, E. coli DH5α, operon phbCAB, Poly 3-Hydroxybutyrate (PHB).

Response surface methodology (RSM) was used to optimize the cultivation conditions for the production of phytase by recombinant Escherichia coli DH5α. The optimum predicted cultivation conditions for phytase production were at 3 hours seed age, a 2.5% inoculum level, an L-arabinose concentration of 0.20%, a cell concentration of 0.3 (as measured at 600 nm) and 17 hours post-induction time with ...

In an attempt to clone the ORF of the nptII gene of Escherichia coli K12 (ATCC 10798), two degenerate primers were designed based on the nptII sequence of its Tn5 transposon. The nptII ORF was placed under the control of the E. coli hybrid trc promoter, in the pKK388-1 vector, transformed into E. coli DH5α ΔrecA (recombinant, deficient strain). Transferred cells were tested for ampicillin, tetr...

A carboxymethyl cellulase gene, cel5B, was cloned, sequenced, and expressed in Escherichia coli. pRCS20 in E. coli was identified from metagenomic cosmid library of cow rumen for cellulase activity on a carboxymethyl cellulose agar plates. Cosmid clone (RCS20) was partially digested with Sau3AI, ligated into BamHI site of pBluescript II SK+ vector, and transformed into E. coli DH5α. The insert ...