scholarly journals Selection of purification condition for recombinant endoglucanase originated from goat rumen bacteria in Escherichia coli

2020 ◽  
Vol 42 (1) ◽  
Author(s):  
Nguyen Thi Quy ◽  
Nguyen Hong Duong ◽  
Dao Trong Khoa ◽  
Nguyen Khanh Hoang Viet ◽  
Nguyen Khanh Hai ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Phosphate Buffer ◽  
Economic Value ◽  
Metagenomic Data ◽  
Affinity Column ◽  
Clear Zone ◽  
His Tag ◽  
Recombinant Cellulase ◽  
Important Enzyme ◽  
Selection Of

Cellulase is an important enzyme that plays a role in cleaving β-1,4 glucoside on cellulose to release glucose, which is of economic value and can be applied in many different fields. The 1545 bp endoglucanase gene mined from goat rumen's bacterial metagenomic data was expressed in Escherichia coli Rosetta2. In this study, the recombinant endoglucanase was purified by his-tag affinity chromatography with differrent processes, such as using phosphate buffer with or without sodium cloride, pretreatment of samples with ammonium sulphate before supplying into affinity column, using various concentration of imidazole for washing... Finally the endoglucanse was sucessfully purified by his-tag affinity column using sodium chloride-free phosphate buffer of which 150 mM and 400 mM imidazole were used for washing and enzyme elution, respectively. The resulting enzyme showed its high purity of 99%. CMC plate assay confirmed that although less active than commercial cellulase (Sigma), the recombinant cellulase hydrolyzed CMC to form a clear zone (halo) around the well. The purified enzyme is capable of using as material for further analysis. 

The selection of optimum fermentation condition for improved expression of sumo-il11 in escherichia coli

2015 ◽  
Vol 37 (1se) ◽  
Author(s):  
Nguyen Thi Quy ◽  
Duong Thu Huong ◽  
Dang Thi Ngoc Ha ◽  
Le Thi Thu Hong ◽  
Do Thi Huyen ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Fermentation Condition ◽  
Selection Of

Construction and Functional Analysis of the Recombinant Bacteriocins Weissellicin-MBF from Weissella confusa MBF8-1

2020 ◽  
Vol 22 (1) ◽  
pp. 115-122
Author(s):  
Amarila Malik ◽  
Elita Yuliantie ◽  
Nisa Yulianti Suprahman ◽  
Theresa Linardi ◽  
Angelina Wening Widiyanti ◽  
...  
Keyword(s):  
Functional Analysis ◽  
Large Scale ◽  
Micrococcus Luteus ◽  
Affinity Column ◽  
Gene Expressions ◽  
His Tag ◽  
Recombinant Peptides ◽  
Weak Activity ◽  
Potential Alternative ◽  
Weissella Confusa

Background: Bacteriocins (Bac1, Bac2, and Bac3) from Weissella confusa MBF8-1, weissellicin- MBF, have been reported as potential alternative substances as well as complements to the existing antibiotics against many antimicrobial-resistant pathogens. Previously, the genes encoded in the large plasmid, pWcMBF8-1, and the spermicidal activity of their synthetic peptides, originally discovered Indonesia, have been studied. Three synthetic bacteriocins peptides of this weissellicin-MBF have been reported for their potential activities, i.e. antibacterial and spermicidal. Objective: The aim of this study was to construct the recombinant Bacteriocin (r-Bac) genes, as well as to investigate the gene expressions and their functional analysis. Method: Here, the recombinant Bacteriocin (r-Bac) genes were constructed and the recombinant peptides (r-Bac1, r-Bac2, and r-Bac3) in B. subtilis DB403 cells were produced on a large scale. After purification, using the His-tag affinity column, their potential bioactivities were measured as well as their antibacterial minimum inhibitory concentrations against Leuconostoc mesenteroides and Micrococcus luteus, were determined. Results: Pure His-tag-recombinant Bac1, Bac2, and Bac3 were obtained and they could inhibit the growth of L. mesenteroides and M. luteus. Conclusion: The recombinant bacteriocin could be obtained although with weak activity in inhibiting gram-positive bacterial growth.

scholarly journals Selection and co-selection of antibiotic resistances among Escherichia coli by antibiotic use in primary care: An ecological analysis

PLoS ONE ◽  
2019 ◽  
Vol 14 (6) ◽  
pp. e0218134 ◽  
Author(s):  
Koen B. Pouwels ◽  
Berit Muller-Pebody ◽  
Timo Smieszek ◽  
Susan Hopkins ◽  
Julie V. Robotham
Keyword(s):  
Escherichia Coli ◽  
Primary Care ◽  
Antibiotic Use ◽  
Ecological Analysis ◽  
Selection Of

scholarly journals Comparison of Common Enrichment Broths Used in Diagnostic Laboratories for Shiga Toxin—Producing Escherichia coli

2021 ◽  
Vol 9 (3) ◽  
pp. 503
Author(s):  
Michael Bording-Jorgensen ◽  
Hannah Tyrrell ◽  
Colin Lloyd ◽  
Linda Chui
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Real Time Pcr ◽  
Acute Gastroenteritis ◽  
Diagnostic Testing ◽  
First Line ◽  
Gram Negative ◽  
Culture Independent ◽  
Surveillance Programs ◽  
Selection Of

Acute gastroenteritis caused by Shiga toxin-producing Escherichia coli (STEC) affects more than 4 million individuals in Canada. Diagnostic laboratories are shifting towards culture-independent diagnostic testing; however, recovery of STEC remains an important aspect of surveillance programs. The objective of this study was to compare common broth media used for the enrichment of STEC. Clinical isolates including O157:H7 as well as non-O157 serotypes were cultured in tryptic soy (TSB), MacConkey (Mac), and Gram-negative (GN) broths and growth was compared using culture on sheep’s blood agar and real-time PCR (qPCR). In addition, a selection of the same isolates was spiked into negative stool and enriched in the same three broths, which were then evaluated using culture on CHROMagarTM STEC agar and qPCR. TSB was found to provide the optimal enrichment for growth of isolates with and without stool. The results from this study suggest that diagnostic laboratories may benefit from enriching STEC samples in TSB as a first line enrichment instead of GN or Mac.

scholarly journals Use of tellurite for the selection of verocytotoxigenic Escherichia coli O157

1993 ◽  
Vol 39 (2) ◽  
pp. 155-158 ◽  
Author(s):  
P. M. Zadik ◽  
P. A. Chapman ◽  
C. A. Siddons
Keyword(s):  
Escherichia Coli ◽  
Escherichia Coli O157 ◽  
Selection Of

Selection of Sucrose-Dependent Escherichia coli To Obtain Envelope Mutants and Fragile Cultures

Science ◽  
1966 ◽  
Vol 153 (3738) ◽  
pp. 892-894 ◽  
Author(s):  
G. Mangiarotti ◽  
D. Apirion ◽  
D. Schlessinger
Keyword(s):  
Escherichia Coli ◽  
Selection Of

Selection of Swine Resistant to F4-Positive Escherichia coli

1997 ◽  
pp. 427-429
Author(s):  
A. Bertels ◽  
J. Jourquin ◽  
N. Buys ◽  
A. Van Zeveren ◽  
H. De Greve ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Selection Of

Reduction of Escherichia coli O157:H7 Counts on Whole Fresh Apples by Treatment with Sanitizers

2000 ◽  
Vol 63 (6) ◽  
pp. 703-708 ◽  
Author(s):  
MARCY A. WISNIEWSKY ◽  
BONITA A. GLATZ ◽  
MARK L. GLEASON ◽  
CHERYLL A. REITMEIER
Keyword(s):  
Escherichia Coli ◽  
Chlorine Dioxide ◽  
Phosphate Buffer ◽  
Phosphate Buffer Solution ◽  
Escherichia Coli O157 ◽  
Peroxyacetic Acid ◽  
Water Control ◽  
Buffer Solution ◽  
E Coli ◽  
Log Reduction

The objectives of this study were to determine if washing of whole apples with solutions of three different sanitizers (peroxyacetic acid, chlorine dioxide, or a chlorine-phosphate buffer solution) could reduce a contaminating nonpathogenic Escherichia coli O157:H7 population by 5 logs and at what sanitizer concentration and wash time such a reduction could be achieved. Sanitizers were tested at 1, 2, 4, 8, and 16 times the manufacturer's recommended concentration at wash times of 5, 10, and 15 min. Whole, sound Braeburn apples were inoculated with approximately 1 × 108 or 7 × 106 CFU per apple, stored for 24 h, then washed with sterile water (control) or with sanitizers for the prescribed time. Recovered bacteria were enumerated on trypticase soy agar. Washing with water alone reduced the recoverable population by almost 2 logs from the starting population; this can be attributed to physical removal of organisms from the apple surface. No sanitizer, when used at the recommended concentration, reduced the recovered E. coli population by 5 logs under the test conditions. The most effective sanitizer, peroxyacetic acid, achieved a 5-log reduction when used at 2.1 to 14 times its recommended concentration, depending on the length of the wash time. The chlorine-phosphate buffer solution reduced the population by 5 logs when used at 3 to 15 times its recommended concentration, depending on wash time. At no concentration or wash time tested did chlorine dioxide achieve the 5-log reduction.

Attachment of Shiga Toxigenic Escherichia coli to Beef Muscle and Adipose Tissue

2006 ◽  
Vol 69 (5) ◽  
pp. 999-1006 ◽  
Author(s):  
LUCIA RIVAS ◽  
GARY A. DYKES ◽  
NARELLE FEGAN
Keyword(s):  
Escherichia Coli ◽  
Adipose Tissue ◽  
Foodborne Pathogens ◽  
Gastrointestinal Disease ◽  
Attached Bacteria ◽  
The Mean ◽  
Bacterial Hydrophobicity ◽  
Adipose Tissue Cells ◽  
Selection Of ◽  
Beef Muscle

Shiga toxigenic Escherichia coli (STEC) serotypes are important foodborne pathogens that cause gastrointestinal disease worldwide. An understanding of how STEC strains attach to surfaces may provide insight into the potential persistence of and contamination with STEC in food environments. The initial attachment of a selection of STEC serotypes to beef muscle and adipose tissue was evaluated for isolates grown in planktonic and sessile culture. Initial experiments were performed to determine whether attachment differed among STEC strains and between the two modes of growth. Viable counts were obtained for loosely and strongly attached cells, and the strength of attachment (Sr) was calculated. All bacterial isolates grown in sessile culture attached in higher numbers to muscle and adipose tissue than did bacteria in planktonic cultures. For all attachment assays performed, mean concentrations for loosely attached cells were consistently higher than concentrations for strongly attached cells. The mean concentrations for strongly attached bacteria for planktonic and sessile cultures were significantly higher (P < 0.05) on adipose than on muscle tissue. However, some strains of STEC, particularly those from sessile culture, did not differ in their attachment to muscle or adipose tissue. Sr values were not significantly different (P > 0.05) among STEC isolates for all assays. No correlation was found between bacterial hydrophobicity and surface charge values (previously determined) and production of surface structures, viable counts, and Sr values. STEC grown in planktonic and sessile culture seems to behave differently with respect to attachment to muscle and adipose tissue. Cells in sessile culture may have a greater potential to strongly attach to meat surfaces.

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