scholarly journals Cell-Free Mixing of Escherichia coli Crude Extracts to Prototype and Rationally Engineer High-Titer Mevalonate Synthesis

2016 ◽  
Vol 5 (12) ◽  
pp. 1578-1588 ◽  
Author(s):  
Quentin M. Dudley ◽  
Kim C. Anderson ◽  
Michael C. Jewett
Keyword(s):  
Escherichia Coli ◽  
High Titer ◽  
Crude Extracts

Study effect of crude extracts of Hibiscus sabdarifa L. on some Enterobacteriaceae

2018 ◽  
Vol 9 (SPL1) ◽  
Author(s):  
Sabreen A Kamal ◽  
Ishraq A Salih ◽  
Hawraa Jawad Kadhim ◽  
Zainab A Tolaifeh
Keyword(s):  
Escherichia Coli ◽  
Ethyl Acetate ◽  
Bacterial Growth ◽  
Chemical Compounds ◽  
Inhibition Zone ◽  
Crude Extracts ◽  
And Control

Red rose or roselle (beauty rose ) is natively known as red tea belong to Malvaceae, it is flowers use traditionally for antihypertensive hepato protective, anticancer,antidiabetic,antibacterial, cytotoxicity and antidiarreal, By preparing red tea from it's flower. In this study, we extract chemical compounds by using two solvent which are Ethanol, Ethyl acetate. so we can extract Anthocyanin which is responsible for red colour of flower with many chemical compounds. then study the effect of these extracts on 5 genera from Enterobacteriacaea which can cause diarrheae (Shigella, Salmonella, Escherichia coli, Proteus and Klebsiella ) by preparing 3 concentrations for each solvent (250, 500, 750 ) mg/ml, and control then compare with two antibiotic (Azereonam 30 mg/ml and Bacitracin 10 mg/ml ) these extracts revealed obvious inhibition zone in bacterial growth.

scholarly journals Genome-scale target identification in Escherichia coli for high-titer production of free fatty acids

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Lixia Fang ◽  
Jie Fan ◽  
Shulei Luo ◽  
Yaru Chen ◽  
Congya Wang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Fatty Acids ◽  
Free Fatty Acids ◽  
Stress Responses ◽  
Metabolic Networks ◽  
Target Identification ◽  
High Titer ◽  
Cell Factory ◽  
Microbial Cell Factory ◽  
Ffa Metabolism

AbstractTo construct a superior microbial cell factory for chemical synthesis, a major challenge is to fully exploit cellular potential by identifying and engineering beneficial gene targets in sophisticated metabolic networks. Here, we take advantage of CRISPR interference (CRISPRi) and omics analyses to systematically identify beneficial genes that can be engineered to promote free fatty acids (FFAs) production in Escherichia coli. CRISPRi-mediated genetic perturbation enables the identification of 30 beneficial genes from 108 targets related to FFA metabolism. Then, omics analyses of the FFAs-overproducing strains and a control strain enable the identification of another 26 beneficial genes that are seemingly irrelevant to FFA metabolism. Combinatorial perturbation of four beneficial genes involving cellular stress responses results in a recombinant strain ihfAL−-aidB+-ryfAM−-gadAH−, producing 30.0 g L−1 FFAs in fed-batch fermentation, the maximum titer in E. coli reported to date. Our findings are of help in rewiring cellular metabolism and interwoven intracellular processes to facilitate high-titer production of biochemicals.

scholarly journals ISOLATION AND CHARACTERIZATION OF ACTINOMYCETES FROM SOIL OF AD-DAWADMI, SAUDI ARABIA AND SCREENING THEIR ANTIBACTERIAL ACTIVITIES

2017 ◽  
Vol 9 (10) ◽  
pp. 276 ◽  
Author(s):  
Gouse Basha Sheik ◽  
Muazzam Sheriff Maqbul ◽  
Gokul Shankar S. ◽  
Ranjith M S
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Antibacterial Activities ◽  
Soil Samples ◽  
Streptomyces Sp ◽  
Crude Extracts ◽  
Test Organisms ◽  
Inhibition Zones

Objective: To isolate and characterize novel actinomycetes and to evaluate their antibacterial activity against drug-resistant pathogenic bacteriaMethods: In the present study, 19 soil samples were collected from different localities of Ad-Dawadmi, Saudi Arabia. Actinomycetes were isolated from these samples using serial dilution and plating method on Actinomycetes isolation agar supplemented with nalidixic acid and actidione to inhibit bacteria and fungi. Crude extracts of potential actinomycetes were produced by submerged fermentation. The antimicrobial activity of crude extracts of actinomycetes was tested against different bacteria using the agar well diffusion method. Characterization of the isolates was done by morphological, physiological and biochemical methods.Results: A total of 9 (47%) isolates of actinomycetes were isolated from 19 different soil samples tested. Among them, 4 (44%) isolates confirmed as Streptomyces sp. showed potential antimicrobial activity against one or more test organisms. Crude extracts were made from these 4 actinomycetes isolates(DOM1, DOM3, DP3, DP4)and tested for their antibacterial activities against 4 different clinical bacterial strains (Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Enterococcus). Crude extract from DP3 isolate showed highest antibacterial activity against all the four test organisms (28 mm, 21 mm, 20 mm and 18 mm) respectively and DP4 showed lowest antibacterial activity against all the four test organisms (14 mm, 12 mm, 0 mm, 6 mm) respectively. The highest zone of inhibition was shown by DP3 against Staphylococcus aureus (28 mm) and Escherichia coli was resistant for DP4. Most of the Inhibition zones produced by crude extracts showed significant differences when compared with control, tested against test organisms (P<0.05). Inhibition zones produced by DP3 and DOM1 against Staphylococcus aureus were 28 mm and 23 mm, respectively which were strong active when compared with control Ciprofloxacin (18 mm).Conclusion: Further studies for purification of bioactive metabolites and molecular characterization analysis of isolated Streptomyces sp. are in progress which would be helpful in discovering novel compounds of commercial value.

Immunogenicity Evaluation of Chimeric Subunit Vaccine Comprising Adhesion Coli Surface Antigens from Enterotoxigenic Escherichia coli

2019 ◽  
Vol 29 (1-6) ◽  
pp. 91-100
Author(s):  
Dorna Khoobbakht ◽  
Shohreh Zare Karizi ◽  
Mohammad Javad  Motamedi ◽  
Rouhollah Kazemi ◽  
Pooneh Roghanian ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Epithelial Cells ◽  
Subunit Vaccine ◽  
Fusion Gene ◽  
Intestinal Epithelial Cells ◽  
High Titer ◽  
Chimeric Protein ◽  
Amino Acid Sequences ◽  
Intestinal Epithelial ◽  
E Coli

Enterotoxigenic <i>Escherichia coli</i> (ETEC) is the most common agent of diarrhea morbidity in developing countries. ETEC adheres to host intestinal epithelial cells via various colonization factors. The CooD and CotD proteins play a significant role in bacteria binding to the intestinal epithelial cells as adhesin tip subunits of CS1 and CS2 pili. The purpose here was to design a new construction containing <i>cooD</i> and <i>cotD</i> genes and use several types of bioinformatics software to predict the structural and immunological properties of the designed antigen. The fusion gene was synthesized with codon bias of <i>E. coli</i> in order to increase the expression level of the protein. The amino acid sequences, protein structure, and immunogenicity properties of potential antigens were analyzed in silico. The chimeric protein was expressed in <i>E. coli</i>BL21 (DE3). The antigenicity of the recombinant proteins was verified by Western blotting and ELISA. In order to assess the induced immunity, the immunized mice were challenged with wild-type ETEC by an intraperitoneal route. Immunological analyses showed the production of a high titer of IgG serum with no sign of serum-mucosal IgA antibody response. The result of the challenge assay showed that 30% of immunized mice survived. The results of this study showed that CooD-CotD recombinant protein can stimulate immunity against ETEC. The designed chimera could be a prototype for the subunit vaccine, which is worthy of further consideration.

scholarly journals Multi-Path Optimization for Efficient Production of 2′-Fucosyllactose in an Engineered Escherichia coli C41 (DE3) Derivative

2020 ◽  
Vol 8 ◽  
Author(s):  
Zhijian Ni ◽  
Zhongkui Li ◽  
Jinyong Wu ◽  
Yuanfei Ge ◽  
Yingxue Liao ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Batch Fermentation ◽  
Infant Nutrition ◽  
High Titer ◽  
Production Performance ◽  
Cell Factory ◽  
Efficient Production ◽  
Healthy Development ◽  
Fucosyltransferase Gene ◽  
Fed Batch Fermentation

2′-fucosyllactose (2′-FL), one of the simplest but most abundant oligosaccharides in human milk, has been demonstrated to have many positive benefits for the healthy development of newborns. However, the high-cost production and limited availability restrict its widespread use in infant nutrition and further research on its potential functions. In this study, on the basis of previous achievements, we developed a powerful cell factory by using a lacZ-mutant Escherichia coli C41 (DE3)ΔZ to ulteriorly increase 2′-FL production by feeding inexpensive glycerol. Initially, we co-expressed the genes for GDP-L-fucose biosynthesis and heterologous α-1,2-fucosyltransferase in C41(DE3)ΔZ through different plasmid-based expression combinations, functionally constructing a preferred route for 2′-FL biosynthesis. To further boost the carbon flux from GDP-L-fucose toward 2′-FL synthesis, deletion of chromosomal genes (wcaJ, nudD, and nudK) involved in the degradation of the precursors GDP-L-fucose and GDP-mannose were performed. Notably, the co-introduction of two heterologous positive regulators, RcsA and RcsB, was confirmed to be more conducive to GDP-L-fucose formation and thus 2′-FL production. Further a genomic integration of an individual copy of α-1,2-fucosyltransferase gene, as well as the preliminary optimization of fermentation conditions enabled the resulting engineered strain to achieve a high titer and yield. By collectively taking into account the intracellular lactose utilization, GDP-L-fucose availability, and fucosylation activity for 2′-FL production, ultimately a highest titer of 2′-FL in our optimized conditions reached 6.86 g/L with a yield of 0.92 mol/mol from lactose in the batch fermentation. Moreover, the feasibility of mass production was demonstrated in a 50-L fed-batch fermentation system in which a maximum titer of 66.80 g/L 2′-FL was achieved with a yield of 0.89 mol 2′-FL/mol lactose and a productivity of approximately 0.95 g/L/h 2′-FL. As a proof of concept, our preliminary 2′-FL production demonstrated a superior production performance, which will provide a promising candidate process for further industrial production.

A novel phosphoprotein dependent on the bacterial phosphoenolpyruvate–sugar phosphotransferase system

1983 ◽  
Vol 61 (2-3) ◽  
pp. 150-153 ◽  
Author(s):  
E. Bruce Waygood ◽  
Roshan L. Mattoo
Keyword(s):  
Escherichia Coli ◽  
Salmonella Typhimurium ◽  
Growth Conditions ◽  
Phosphotransferase System ◽  
Crude Extracts ◽  
Enzyme I ◽  
Novel Protein

A protein has been found by isoelectricfocusing and autoradiography in Escherichia coli and Salmonella typhimurium which was phosphorylated by enzyme I and an histidine-containing phosphocarrier protein (HPr) of the phosphoenolpyruvate–sugar phosphotransferase system (PTS). This protein was not factor IIIglc nor was it specifically induced by fructose. Its presence in soluble crude extracts was dependent upon growth conditions; however, the two bacteria had different patterns and amounts in respect to this novel protein. The protein was present in S. typhimurium SB2950 which has an extensive deletion through the pts operon, thus indicating that it must be coded for elsewhere on the genome.

scholarly journals Genome-wide targets identification by CRISPRi-Omics for high-titer production of free fatty acids in Escherichia coli

2020 ◽  
Author(s):  
Lixia Fang ◽  
Jie Fan ◽  
Congya Wang ◽  
Yingxiu Cao ◽  
Hao Song
Keyword(s):  
Escherichia Coli ◽  
Fatty Acids ◽  
Free Fatty Acids ◽  
Metabolic Networks ◽  
High Titer ◽  
Cell Structure ◽  
Cell Factory ◽  
Microbial Cell Factory ◽  
Cell Potential ◽  
E Coli

AbstractTo construct a superior microbial cell factory for chemical synthesis, a major challenge is to fully exploit cell potential via identifying and engineering beneficial gene targets in the sophisticated metabolic networks. Here, we develop an approach that integrates CRISPR interference (CRISPRi) to readily modulate genes expression and omics analyses to identify potential targets in multiple cellular processes, enabling systematical discovery of beneficial chromosomal gene targets that can be engineered to optimize free fatty acids (FFAs) production in Escherichia coli. We identify 56 beneficial genes via synergistic CRISPRi-Omics strategy, including 46 novel targets functioning in cell structure and division, and signaling transduction that efficiently facilitate FFAs production. Upon repressing ihfA and overexpressing aidB and tesA’ in E. coli, the recombinant strain LihfA-OaidB results in a FFAs titer of 21.6 g L-1 in fed-batch fermentation, which, to our best knowledge, is the maximum FFAs titer by the recombinant E. coli reported to date.

EFFECTS OF HOMOLOGOUS AND HETEROLOGOUS ANTISERA ON THE GLYCEROL DEHYDROGENASES OF HALOPHILIC AND NON-HALOPHILIC BACTERIA

1955 ◽  
Vol 1 (4) ◽  
pp. 262-265 ◽  
Author(s):  
R. M. Baxter ◽  
N. E. Gibbons
Keyword(s):  
Escherichia Coli ◽  
Halophilic Bacteria ◽  
E Coli ◽  
Crude Extracts ◽  
Minimal Quantity ◽  
Original Preparation

Antisera against the glycerol dehydrogenases of Escherichia coli and Vibrio costicolus, prepared by injecting the enzymes into rabbits, precipitated the homologous but not the heterologous enzymes. When the enzyme from E. coli was completely precipitated from the supernatant by a minimal quantity of antiserum, about half the activity could be demonstrated in the precipitate. The activity of the precipitate was progressively reduced by increasing amounts of antiserum. Crude extracts of V. costicolus oxidized butanediol as well as glycerol. The antiserum reduced the oxidation of glycerol to a greater extent than the oxidation of butanediol indicating the presence of two enzymes in the original preparation. Antisera against the E. coli and V. costicolus enzymes were inactive against the P. salinaria enzyme. An attempt to prepare antibodies against the enzyme from Pseudomonas salinaria was not successful.

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