Facilitating the enzymatic conversion of lysine to cadaverine in engineered Escherichia coli with metabolic regulation by genes deletion

In this study, nine different types of deletion strains were constructed from the aforementioned four genes to explore their effects on cadaverine production in a T7 promoter based systemic bicistronic cadA-cadB transformed recombinant E. coli. Results show that all the deletion strains could increase cadaverine productivity compared to the deletion-free strain when the culture was supplemented with L-lysine. The cadaverine production from L-lysine with the deletion strains increased 3 folds when compared with that of the deletion-free strain at the cultivation time of 16 h. This indicates that the deletion strain could successfully facilitate lysine consumption and block the undesirable metabolic pathways.Graphical abstract
Source: Biochemical Engineering Journal - Category: Biochemistry Source Type: research

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This study characterized Listeria monocytogenes, Salmonella enterica, and E. coli O157:H7 by collecting rectoanal mucosal swabs and fecal samples from 518 imported beef cattle at Jordan’s major abattoir. A unique 53 L. monocytogenes, 287 S. enterica, and 17 E. coli O157:H7 were isolated from 37, 120 and 9 different animals; respectively. The prevalence of S. enterica, L. monocytogenes and E. coli O157:H7 were 23.2% (95% CI, 19.7-27.0%), 7.1% (95% CI, 5.2-9.7%) and 1.7% (95% CI, 0.9-3.3%); respectively. All L. monocytogenes, all E. coli O157:H7 and 93.0% of S. enterica isolates resisted at least one antimicrobial clas...
Source: Comparative Immunology, Microbiology and Infectious Diseases - Category: Infectious Diseases Source Type: research
Authors: Mann M, Calio BP, Mark JR, Chelluri R, Hufnagel E, Reese A, Lallas CD, Trabulsi EJ, Chandrasekar T, Shenot PJ, Halpern E, Gomella LG Abstract INTRODUCTION: To assess whether standard American Urological Association (AUA) and other recommendations for prostate biopsy prophylaxis provide sufficient coverage of common urinary organisms responsible for post biopsy infections by comparing local antibiograms in Philadelphia-area hospitals. MATERIALS AND METHODS: De-identified culture results derived from antibiograms were collected from six academic and community hospitals in the Philadelphia region. Analysi...
Source: Canadian Journal of Urology - Category: Urology & Nephrology Tags: Can J Urol Source Type: research
Authors: O'Riordan J, Bhally HS, Salmon AH, de Zoysa JR Abstract Multidrug-resistant organisms cause significant morbidity and mortality. Infections due to resistant gram-negative bacilli are increasingly being reported. For years, carbapenem antibiotics have been successfully used to treat infections due to resistant Enterobacteriaceae, such as Escherichia coli and Klebsiella pneumoniae, including those producing extended spectrum β-lactamases, a subset of β-lactamase enzymes that confer broad resistance to penicillins and cephalosporins. More recently, carbapenem-resistant Enterobacteriaceae have emerge...
Source: Peritoneal Dialysis International - Category: Urology & Nephrology Tags: Perit Dial Int Source Type: research
ConclusionResearch performed in the past 25 years on specialized metabolites derived from plants with antiprotozoal activity has yielded relevant findings whose results provide evidence-based support for the use of these plants in the traditional medicine of Mexico to treat diarrhoea. Toxicological and clinical trials of standardized extracts and bioactive compounds are proposed as priority future works in this research area. In addition, in vivo assays are required, of more extracts and/or pure compounds. The optimization of the pharmacological properties of the bioactive specialized metabolites through semisynthetic deri...
Source: Journal of Ethnopharmacology - Category: Drugs & Pharmacology Source Type: research
Publication date: September 2020Source: Materials Today Communications, Volume 24Author(s): Chanon Talodthaisong, Wissuta Boonta, Saengrawee Thammawithan, Rina Patramanon, Nuntaporn Kamonsutthipaijit, James A. Hutchison, Sirinan KulchatAbstractBiomaterial-based hydrogels incorporating antibacterial agents may provide sustainable solutions to biomedical device failures and the prevention of infections. Herein we report guar gum hydrogels, cross-linked with borax and loaded with silver nanoparticles, that are injectable, exhibit rapid self-healing, and show antibacterial properties towards both gram-positive and gram-negativ...
Source: Materials Today Communications - Category: Materials Science Source Type: research
Publication date: Available online 19 February 2020Source: Materials LettersAuthor(s): Yang Jiao, Qian Liu, Jihua ChenAbstractClinically, non-desired osseointegration and bacterial-associated infection are responsible for the failure of titanium (Ti)-based implantation in orthopedic field. Herein, bone morphogenetic protein 2 (BMP2) loaded TiO2 nanotubes (TNT) arrays were fabricated on Ti substrates. Next, bioactive multilayer films of MA-modified gelatin (GelMA) and N-Cl modification poly (N, N’-methylene bis(acrylamide)) (PMAA-Cl) were deposited onto the BMP2-loaded TNT substrates with layer-by-layer (LBL) self-ass...
Source: Materials Letters - Category: Materials Science Source Type: research
Publication date: Available online 19 February 2020Source: Materials LettersAuthor(s): Jingxiang Zhang, Shengqian Zhu, Kunkun Song, Zhuoyue Wang, Zongpu Han, Keren Zhao, Zengjie Fan, Xi Zhou, Qiangqiang ZhangAbstractThree-dimensional (3D) graphene/nano-copper scaffolds (rGCSs) was fabricated using a one-step chemical deposition on 3D reduced graphene oxide architecture (rGOA). The nano-copper was conformably grown on the rGOA substrate with a uniform morphology. Due to combined effects between the graphene skeleton and the nano-copper, the rGCSs demonstrated excellent antibacterial properties in the colony counting experim...
Source: Materials Letters - Category: Materials Science Source Type: research
Publication date: 18 February 2020Source: Cell Reports, Volume 30, Issue 7Author(s): Michael J. Ormsby, Síle A. Johnson, Nuria Carpena, Lynsey M. Meikle, Robert J. Goldstone, Anne McIntosh, Hannah M. Wessel, Heather E. Hulme, Ceilidh C. McConnachie, James P.R. Connolly, Andrew J. Roe, Conor Hasson, Joseph Boyd, Eamonn Fitzgerald, Konstantinos Gerasimidis, Douglas Morrison, Georgina L. Hold, Richard Hansen, Daniel Walker, David G.E. SmithSummaryPropionic acid (PA) is a bacterium-derived intestinal antimicrobial and immune modulator used widely in food production and agriculture. Passage of Crohn’s disease-assoc...
Source: Cell Reports - Category: Cytology Source Type: research
This study evaluates the application of thermosonication for the inactivation of pathogenic microorganisms, and its effect on antioxidant activity and retinol level in donated human milk. We evaluate the effect of thermosonication on Staphylococcus aureus, Escherichia coli, and Salmonella spp. microorganisms in human milk by analyzing the effect of time and temperature of the thermosonication on these microorganisms using a central composite rotatable design. Also evaluated the effects of thermosonication (60 °C/4 min) on antioxidant activity using DPHH (2, 2-diphenyl-1-picrylhydrazyl) free radical and ABTS (2,2&pr...
Source: Food Control - Category: Food Science Source Type: research
The objectives of this study were to 1) identify along the raspberry supply chain the most influential factors of E. coli and HAV contamination in the final products; and 2) evaluate the efficacies of possible interventions to control these influential factors. To achieve these objectives, a unified quantitative model of microbial contamination in raspberries was developed to describe the impact of factors in a continuum from the farm to the destination of importation on E. coli/HAV contamination in fresh and frozen raspberry products. Multiple surveys were conducted to obtain country-specific data on current common practi...
Source: Food Control - Category: Food Science Source Type: research
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