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e coli plasmid strain development

Seon Young Park, Robert M Binkley, Won Jun Kim, Mun Hee Lee, Sang Yup Lee
Astaxanthin is a reddish keto-carotenoid classified as a xanthophyll found in various microbes and marine organisms. As a powerful antioxidant having up to 100 times more potency than other carotenoids such as β-carotene, lutein, and lycopene, astaxanthin is a versatile compound utilized in animal feed, food pigment, health promotion and cosmetic industry. Here, we report development of metabolically engineered Escherichia coli capable of producing astaxanthin to a high concentration with high productivity...
August 7, 2018: Metabolic Engineering
Johana E Dominguez, Leandro M Redondo, Roque A Figueroa Espinosa, Daniela Cejas, Gabriel O Gutkind, Pablo A Chacana, José A Di Conza, Mariano E Fernández Miyakawa
The use of antimicrobial growth promoters (AGPs) in sub-therapeutic doses for long periods promotes the selection of resistant microorganisms and the subsequent risk of spreading this resistance to the human population and the environment. Global concern about antimicrobial resistance development and transference of resistance genes from animal to human has been rising. The goal of our research was to evaluate the susceptibility pattern to different classes of antimicrobials of colistin-resistant Escherichia coli from poultry production systems that use AGPs, and characterize the resistance determinants associated to transferable platforms...
2018: Frontiers in Microbiology
Ye Li, Shuai Qian, Rachel Dunn, Patrick C Cirino
Triacetic acid lactone (TAL) (4-hydroxy-6-methyl-2-pyrone) can be upgraded into a variety of higher-value products, and has potential to be developed into a renewable platform chemical through metabolic engineering. We previously developed an endogenous TAL sensor based on the regulatory protein AraC, and applied it to screen 2-pyrone synthase (2-PS) variant libraries in E. coli, resulting in the identification of variants conferring up to 20-fold improved TAL production in liquid culture. In this study, the sensor-reporter system was further optimized and used to further improve TAL production from recombinant E...
July 25, 2018: Journal of Industrial Microbiology & Biotechnology
Mehreen Anjum, Jonas Stenløkke Madsen, Carmen Espinosa-Gongora, Bimal Jana, Maria Wiese, Dennis Sandris Nielsen, Søren Johannes Sørensen, Arshnee Moodley, Valeria Bortolaia, Luca Guardabassi
IncI1 plasmids play a central role in the transfer of antimicrobial resistance genes among Enterobacteriaceae in animals and humans. Knowledge on the dynamics of IncI1 plasmid transfer is limited, mainly due to lack of culture-independent methods that can quantify donor strain survival and plasmid transfer in complex microbial communities. The aim of this study was to develop a culture-independent method to study the dynamics of IncI1 plasmids transfer by fluorescence-activated cell sorting. We genetically modified three wild-type Escherichia coli of animal (n = 2) and human (n = 1) origin carrying blaCMY-2 or blaCTX-M-1 on two epidemic IncI1 plasmids (pST12 and pST7)...
July 18, 2018: Journal of Microbiological Methods
Eveline Brodl, Johannes Niederhauser, Peter Macheroux
There is a considerable number of bacterial species capable of emitting light. All of them share the same gene cluster, namely the lux operon. Despite this similarity, these bacteria show extreme variations in characteristics like growth behavior, intensity of light emission or regulation of bioluminescence. The method presented here is a newly developed assay that combines recording of cell growth and bioluminescent light emission intensity over time utilizing a plate reader. The resulting growth and light emission characteristics can be linked to important features of the respective bacterial strain, such as quorum sensing regulation...
June 28, 2018: Journal of Visualized Experiments: JoVE
Emilie Racine, Patrice Nordmann, Lucile Pantel, Matthieu Sarciaux, Marine Serri, Jessica Houard, Philippe Villain-Guillot, Anthony Demords, Carina Vingsbo Lundberg, Maxime Gualtieri
Antibacterial activity screening of a collection of Xenorhabdus strains led to the discovery of the Odilorhabdins, a new antibiotic class with broad-spectrum activity against Gram-positive and Gram-negative pathogens. Odilorhabdins inhibit bacterial translation by a new mechanism of action on ribosomes. A lead-optimization program identified NOSO-502 as a promising candidate. NOSO-502 has MIC values ranging from 0.5 to 4 μg/ml against standard Enterobacteriaceae strains and carbapenem-resistant Enterobacteriaceae (CRE) isolates that produce KPC, AmpC, or OXA enzymes and metallo-β-lactamases...
July 9, 2018: Antimicrobial Agents and Chemotherapy
Bin Xiong, Zhongkang Li, Li Liu, Dongdong Zhao, Xueli Zhang, Changhao Bi
Background: Ralstonia eutropha is an important bacterium for the study of polyhydroxyalkanoates (PHAs) synthesis and CO2 fixation, which makes it a potential strain for industrial PHA production and attractive host for CO2 conversion. Although the bacterium is not recalcitrant to genetic manipulation, current methods for genome editing based on group II introns or single crossover integration of a suicide plasmid are inefficient and time-consuming, which limits the genetic engineering of this organism...
2018: Biotechnology for Biofuels
Hailiang Li, Shaoming Mao, Huahai Chen, Liying Zhu, Wei Liu, Xin Wang, Yeshi Yin
( S )-equol is one of the major metabolites of daidzein that is produced by human and animal gut bacteria. Most of the physiological functions of soybean isoflavones, such as anti-oxidative activity, anti-cancer activity, and cardiovascular protection have been ascribed to ( S )-equol. However, only 30-50% people contain this kind of equol-producing bacteria, and therefore are able to convert daidzein to ( S )-equol. Administration of ( S )-equol may be more beneficial than soybean isoflavones. The aim of this study was to construct an engineered ( S )-equol resistant Escherichia coli to enhance ( S )-equol production in vitro ...
2018: Frontiers in Microbiology
Weihua Jin, Shuai Li, Jiale Chen, Bing Liu, Jie Li, Xueliang Li, Fuming Zhang, Robert J Linhardt, Weihong Zhong
Heparan sulfate (HS), is a glycosaminoglycan (GAG) involved in various biological processes, including blood coagulation, wound healing and embryonic development. HS 3-O-sulfotransferases (3-OST), which transfer the sulfo group to the 3-hydroxyl group of certain glucosamine residues, is a key enzyme in the biosynthesis of a number of biologically important HS chains. The 3-OST-1 isoform is one of the 7 known 3-OST isoforms and is important for the biosynthesis of anticoagulant HS chains. In this study, we cloned 3-OST-1 from the rat brain by reverse transcription-polymerase chain reaction (RT-PCR)...
June 9, 2018: Protein Expression and Purification
Tiwa Rotchanapreeda, Wasinee Ngonsawan, Manadsaree Klomtun, Jamorn Somana
For decades, diverse plasmid vectors have been continuously developed for molecular cloning of DNA fragment in the bacterial host cell Escherichia coli. Even with deliberate performances in vector preparation, the cloning approaches still face inevitable background colonies, or false positive clones, that may be arisen from intact or self-ligated plasmid molecules. To assist in such problem, two plasmids, pBS2ndd and pBS3ndd, which resistant to ampicillin and kanamycin respectively, were developed in this study as more advantageous cloning vector...
June 6, 2018: World Journal of Microbiology & Biotechnology
Meng Huang, Xin Lu, Hong Zong, Bin Zhuge, Wei Shen
The low solubility and high-cost recovery of Propionibacterium acnes polyunsaturated fatty acid isomerase (PAI) are key problems in the bioproduction of high value-added conjugated linoleic acid (CLA). To improve the solubility of recombinant PAI, six chaperone proteins were coexpressed with PAI. Introduction of GroELS proteins dramatically improved the PAI solubility from 29% to 97%, with increased activity by 57.8%. Combined expression of DnaKJ-GrpE and GroELS proteins increased the activity by 11.9%. In contrast, coexpression of DnaKJ-GrpE proteins significantly reduced the activity by 57...
May 28, 2018: Journal of Microbiology and Biotechnology
Yingjie Zhou, Johan Memelink, Huub J M Linthorst
Salicylic acid (SA) is an essential hormone for development and induced defense against biotrophic pathogens in plants. The formation of SA mainly derives from chorismate via demonstrated isochorismate synthase (ICS) and presumed isochorismate pyruvate lyase (IPL)-mediated steps in Arabidopsis thaliana, but so far no plant enzyme displaying IPL activity has been identified. Here, we developed an E. coli SA biosensor to screen for IPL activity based on the SalR regulator/salA promoter combination from Acinetobacter sp ADP1, to control the expression of the reporter luxCDABE...
May 23, 2018: Molecular Genetics and Genomics: MGG
Elizabeth Bilsland, Tatyana A Tavella, Renata Krogh, Jamie E Stokes, Annabelle Roberts, James Ajioka, David R Spring, Adriano D Andricopulo, Fabio T M Costa, Stephen G Oliver
BACKGROUND: Violacein is a deep violet compound that is produced by a number of bacterial species. It is synthesized from tryptophan by a pathway that involves the sequential action of 5 different enzymes (encoded by genes vioA to vioE). Violacein has antibacterial, antiparasitic, and antiviral activities, and also has the potential of inducing apoptosis in certain cancer cells. RESULTS: Here, we describe the construction of a series of plasmids harboring the complete or partial violacein biosynthesis operon and their use to enable production of violacein and deoxyviolacein in E...
April 11, 2018: BMC Biotechnology
Desi Indriarini, Andriansjah Rukmana, Andi Yasmon
Background: Tuberculosis remains the leading cause of death in the world, especially wherever poverty, malnutrition and poor housing prevail. Mycobacterium tuberculosis Beijing strain is the most common strain that causes tuberculosis in Indonesia. The wide spread of tuberculosis has been further aggravated by HIV-AIDS and drug resistance. Unfortunately, Bacille Calmette-Guerin (BCG) as the current vaccine has different protection function and efficacy. According to function analysis, mce1A gene was predicted to have a role in host invasion and survival of Mycobacterium tuberculosis in human macrophages...
2018: African Journal of Infectious Diseases
Ilya Nikolaevich Zykov, Ørjan Samuelsen, Lotte Jakobsen, Lars Småbrekke, Dan I Andersson, Arnfinn Sundsfjord, Niels Frimodt-Møller
Fosfomycin has become an attractive treatment alternative for urinary tract infections (UTIs) due to increasing multidrug resistance (MDR) in Escherichia coli In this study, we evaluated the pharmacokinetic (PK) and pharmacodynamic (PD) indices of fosfomycin and its in vivo activity in an experimental murine model of ascending UTI. Subcutaneous administration of fosfomycin showed that the mean peak plasma concentrations of fosfomycin were 36, 280, and 750 mg/liter following administration of a single dose of 0...
June 2018: Antimicrobial Agents and Chemotherapy
Elhussiny A Aboulnaga, Huibin Zou, Thorsten Selmer, Mo Xian
Cupriavidus necator H16 gains increasing attention in microbial research and biotechnological application due to its diverse metabolic features. Here we present a tightly controlled gene expression system for C. necator including the pBBR1-vector that contains hybrid promoters originating from C. necator native tolC-promoter in combination with a synthetic tetO-operator. The expression of the reporter gene from these plasmids relies on the addition of the exogenous inducer doxycycline (dc). The novel expression system offers a combination of advantageous features as; (i) high and dose-dependent recombinant protein production, (ii) tight control with a high dynamic range (On/Off ratio), which makes it applicable for harmful pathways or for toxic protein production, (iii) comparable cheap inducer (doxycycline, dc), (iv) effective at low inducer concentration, that makes it useful for large scale application, (v) rapid, diffusion controlled induction, and (vi) the inducer does not interfere within the cell metabolism...
May 20, 2018: Journal of Biotechnology
Ye Zhang, April Z Gu, Tianyu Cen, Xiangyang Li, Dan Li, Jianmin Chen
Particles exhausted from petrol and diesel consumptions are major components of urban air pollution that can be exposed to human via direct inhalation or other routes due to atmospheric deposition into water and soil. Antimicrobial resistance is one of the most serious threats to modern health care. However, how the petrol and diesel exhaust particles affect the development and spread of antimicrobial resistance genes (ARGs) in various environments remain largely unknown. This study investigated the effects and potential mechanisms of four representative petrol and diesel exhaust particles, namely 97 octane petrol, 93 octane petrol, light diesel oil, and marine heavy diesel oil, on the horizontal transfer of ARGs between two opportunistic Escherichia coli (E...
May 2018: Environment International
Marzena Matejczyk, Renata Swislocka, Monika Kalinowska, Grzegorz Widerskp, Wlodzimierz Lewandowsk, Agata Jablonska-Trypuo, Stanislaw Jozef Rosochacki
Cinnamic acid and its derivatives are important and promising compounds in cancer therapy, because of its broad spectrum of anicancer and antioxidative ability, and with high potential for development into new generation drugs. The aim of this study was to compare the cyto- and genotoxic effects of cinnamic acid and its derivatives with the use of4Escherichia coli K-12 recA::gfp microbial biosensor strain with plasmid fusion of recA promoter and gfp gene as reporter. Obtained results indicate that recA::gfpmut2 genetic system was a sensitive biosensor to the most chemicals tested in our experiments...
May 2017: Acta Poloniae Pharmaceutica
Birson Ingti, Pranjit Saikia, Deepjyoti Paul, Anand Prakash Maurya, Debadatta Dhar Chanda, Atanu Chakravarty, Chandrayee Deshamukhya, Amitabha Bhattacharjee
OBJECTIVES: Plasmids of different replicon types are believed to be associated with the carriage and transmission of antimicrobial resistance genes. The present study was undertaken to examine the association of blaCIT with particular plasmid types and to identify Escherichia coli strains involve in the maintenance of this resistance determinant in the plasmid. METHODS: Phenotypic screening of AmpC β-lactamases was performed by the modified three-dimensional extract method, followed by antimicrobial susceptibility testing and determination of minimum inhibitory concentrations (MICs)...
March 2, 2018: Journal of Global Antimicrobial Resistance
Saad Aboualkasem, Debbie S Retnoningrum, Aldila Refiani, Catur Riani
BACKGROUND: Expression vector is an important component in the production of therapeutic recombinant proteins. Most of the commercialized expression vectors apply antibiotic-based selection system. Meanwhile, World Health Organization highly recommends for the alternative system due to its potentials to cause spreading of resistance gene and hypersensitivity to some people. METHODS: In current work, we developed an expression system for Escherichia coli using the toxinantidote system in two separated plasmids...
2017: Current Pharmaceutical Biotechnology
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