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Akashdeep Singh Oberoi, Ligy Philip
In the present study, an attempt was made to understand the variation in the toxicity during the biodegradation of aromatic hydrocarbons in single and multi-substrate system. The bacterial bioassay based on the inhibition of dehydrogenase enzyme activity of two different bacterial sp. E.coli and Pseudomonas fluorescens was used for toxicity assessment. Amongst the chosen pollutants, the highest acute toxicity was observed for benzothiophene followed by benzofuran having EC50 value of 16.60mg/L and 19.30mg/L respectively...
October 19, 2016: Ecotoxicology and Environmental Safety
Shobha Devi, Po-Hung Wu, Pei-Yu Chu, Yue-Pei Liu, Hsin-Lin Wu, Yen-Peng Ho
The impact of microwave irradiation on the in-solution digestion processes and the detection limit of proteins are systematically studied. Kinetic processes of many peptides produced through the trypsin digestion of various proteins under microwave heating at 50°C were investigated with MALDI-MS. This study also examines the detection limits and digestion completeness of individual proteins under microwave heating at 50°C and at different time intervals (1, 5 and 30 min) using LC-MS. We conclude that, if the peptides without missed cleavage dictate the detection limit, conventional digestion will lead to a better detection limit...
October 22, 2016: Electrophoresis
Héloïse Coté, Marie-Anne Boucher, André Pichette, Benoit Roger, Jean Legault
ETHNOPHARMACOLOGICAL RELEVANCE: Oleoresin of Abies balsamea (L.) Mill. was used by Aboriginal people of the boreal forest of Canada and French Canadians to treat various infections, suggesting that oleoresin has antibacterial properties. AIM OF THE STUDY: In this study, the antibacterial activity of whole oleoresin from A. balsamea was investigated against E. coli, S. aureus and two methicillin-resistant S. aureus (MRSA) strains using a new sensitive assay developed to evaluate hydrophobic matrix and compounds...
October 18, 2016: Journal of Ethnopharmacology
J F Leal, I S Henriques, A Correia, E B H Santos, V I Esteves
Oxytetracycline (OTC) is one of the most used antibiotics in aquaculture. The main concern related to its use is the bacterial resistance, when ineffective treatments are applied for its removal or inactivation. OTC photo-degradation has been suggested as an efficient complementary process to conventional methods used in intensive fish production (e.g.: ozonation). Despite this, and knowing that the complete mineralization of OTC is difficult, few studies have examined the antibacterial activity of OTC photoproducts...
October 18, 2016: Environmental Pollution
Xiaoxue Tong, Tania Triscari Barberi, Catherine H Botting, Sunil V Sharma, Mark J H Simmons, Tim W Overton, Rebecca J M Goss
BACKGROUND: Engineering of single-species biofilms for enzymatic generation of fine chemicals is attractive. We have recently demonstrated the utility of an engineered Escherichia coli biofilm as a platform for synthesis of 5-halotryptophan. E. coli PHL644, expressing a recombinant tryptophan synthase, was employed to generate a biofilm. Its rapid deposition, and instigation of biofilm formation, was enforced by employing a spin-down method. The biofilm presents a large three-dimensional surface area, excellent for biocatalysis...
October 21, 2016: Microbial Cell Factories
Marta Gibert, Sonia Paytubi, Sergi Beltrán, Antonio Juárez, Carlos Balsalobre, Cristina Madrid
Plasmids of the incompatibility group HI1 (IncHI1) have been isolated from several Gram-negative pathogens and are associated with the spread of multidrug resistance. Their conjugation is tightly regulated and it is inhibited at temperatures higher than 30°C, indicating that conjugation occurs outside warm-blooded hosts. Using R27, the prototype of IncHI1 plasmids, we report that plasmid transfer efficiency in E. coli strongly depends on the physiological state of the donor cells. Conjugation frequency is high when cells are actively growing, dropping sharply when cells enter the stationary phase of growth...
October 21, 2016: Environmental Microbiology
Nitzan Krinsky, Maya Kaduri, Janna Shainsky-Roitman, Mor Goldfeder, Eran Ivanir, Itai Benhar, Yuval Shoham, Avi Schroeder
Cell-free protein synthesis (CFPS) systems are important laboratory tools that are used for various synthetic biology applications. Here, we present a simple and inexpensive laboratory-scale method for preparing a CFPS system from E. coli. The procedure uses basic lab equipment, a minimal set of reagents, and requires less than one hour to process the bacterial cell mass into a functional S30-T7 extract. BL21(DE3) and MRE600 E. coli strains were used to prepare the S30-T7 extract. The CFPS system was used to produce a set of fluorescent and therapeutic proteins of different molecular weights (up to 66 kDa)...
2016: PloS One
Jean-Emmanuel Hugonnet, Dominique Mengin-Lecreulx, Alejandro Monton, Tanneke den Blaauwen, Etienne Carbonnelle, Carole Veckerlé, Yves Brun, Michael van Nieuwenhze, Christiane Bouchier, Kuyek Tu, Louis B Rice, Michel Arthur
The target of β-lactam antibiotics is the D,D-transpeptidase activity of penicillin-binding proteins (PBPs) for synthesis of 4→3 cross-links in the peptidoglycan of bacterial cell walls. Unusual 3→3 cross-links formed by L,D-transpeptidases were first detected in Escherichia coli more than four decades ago, however no phenotype has previously been associated with their synthesis. Here we show that production of the L,D-transpeptidase YcbB in combination with elevated synthesis of the (p)ppGpp alarmone by RelA lead to full bypass of the D,D-transpeptidase activity of PBPs and to broad-spectrum β-lactam resistance...
October 21, 2016: ELife
Pierre E Affaticati, Shao-Bo Dai, Panwajee Payongsri, Helen C Hailes, Kai Tittmann, Paul A Dalby
The S385Y/D469T/R520Q variant of E. coli transketolase was evolved previously with three successive smart libraries, each guided by different structural, bioinformatical or computational methods. Substrate-walking progressively shifted the target acceptor substrate from phosphorylated aldehydes, towards a non-phosphorylated polar aldehyde, a non-polar aliphatic aldehyde, and finally a non-polar aromatic aldehyde. Kinetic evaluations on three benzaldehyde derivatives, suggested that their active-site binding was differentially sensitive to the S385Y mutation...
October 21, 2016: Scientific Reports
Yasufumi Matsumura, Johann D D Pitout, Ryota Gomi, Tomonari Matsuda, Taro Noguchi, Masaki Yamamoto, Gisele Peirano, Rebekah DeVinney, Patricia A Bradford, Mary R Motyl, Michio Tanaka, Miki Nagao, Shunji Takakura, Satoshi Ichiyama
The Escherichia coli sequence type (ST) 131 C2/H30Rx clade with the blaCTX-M-15 gene had been most responsible for the global dissemination of extended-spectrum β-lactamase (ESBL)-producing E. coli. ST131 C1/H30R with blaCTX-M-27 emerged among ESBL-producing E. coli in Japan during the late 2000s. To investigate the possible expansion of a single clade, we performed whole-genome sequencing for 43 Japan and 10 global ST131 isolates with blaCTX-M-27 (n = 16), blaCTX-M-14 (n = 16), blaCTX-M-15 (n = 13), and others (n = 8)...
November 2016: Emerging Infectious Diseases
Jan Arends, Nikolas Thomanek, Katja Kuhlmann, Katrin Marcus, Franz Narberhaus
FtsH is the only membrane-bound and essential protease in Escherichia coli. It is responsible for the degradation of regulatory proteins and enzymes like the heat-shock sigma factor RpoH or LpxC, the key enzyme of lipopolysaccharide biosynthesis. To find new FtsH targets, we trapped substrates in E. coli cells from exponential and stationary growth phase using a proteolytically inactive FtsH variant. Subsequent analysis of the isolated FtsH-substrate complexes by label-free nanoLC-MS/MS revealed more than 50 putative FtsH substrates, among them five already known substrates...
October 21, 2016: Proteomics
Yi Ma, Jieying Yu, Jinglian Lin, Shaomin Wu, Shan Li, Jufang Wang
Human epidermal growth factor (hEGF) is a small, mitotic growth polypeptide that promotes the proliferation of various cells and is widely applied in clinical practices. However, high efficient expression of native hEGF in Escherichia coli has not been successful, since three disulfide bonds in monomer hEGF made it unable to fold into correct 3D structure using in vivo system. To tackle this problem, we fused Mxe GyrA intein (Mxe) at the C-terminal of hEGF followed by small ubiquitin-related modifier (SUMO) and 10x His-tag to construct a chimeric protein hEGF-Mxe-SUMO-H10...
2016: BioMed Research International
I Løbersli, A L Wester, Å Kristiansen, L T Brandal
A real-time polymerase chain reaction (PCR) assay, amplifying the genes encoding lactose permease (lacY) and invasion plasmid antigen H (ipaH), was run on 121 isolates phenotypically classified as Shigella spp., enteroinvasive Escherichia coli (EIEC), or EIEC O nontypable (ONT). The results were compared with data from a generic E. coli multiple-locus variable-number of tandem repeat analysis (MLVA) and a Shigella MLVA. The real-time PCR verified all Shigella spp. (n = 53) as Shigella (lacY negative) and all EIEC O121 (n = 15) and EIEC O124 (n = 2) as EIEC (lacY positive)...
September 29, 2016: European Journal of Microbiology & Immunology
Trudy M Wassenaar
A century ago, Alfred Nissle discovered that intentional intake of particular strains of Escherichia coli could treat patients suffering from infectious diseases. Since then, one of these strains became the most frequently used probiotic E. coli in research and was applied to a variety of human conditions. Here, properties of that E. coli Nissle 1917 strain are compared with other commercially available E. coli probiotic strains, with emphasis on their human applications. A literature search formed the basis of a summary of research findings reported for the probiotics Mutaflor, Symbioflor 2, and Colinfant...
September 29, 2016: European Journal of Microbiology & Immunology
Whitney D Hollinshead, Sarah Rodriguez, Hector Garcia Martin, George Wang, Edward E K Baidoo, Kenneth L Sale, Jay D Keasling, Aindrila Mukhopadhyay, Yinjie J Tang
BACKGROUND: Glycolysis breakdowns glucose into essential building blocks and ATP/NAD(P)H for the cell, occupying a central role in its growth and bio-production. Among glycolytic pathways, the Entner Doudoroff pathway (EDP) is a more thermodynamically favorable pathway with fewer enzymatic steps than either the Embden-Meyerhof-Parnas pathway (EMPP) or the oxidative pentose phosphate pathway (OPPP). However, Escherichia coli do not use their native EDP for glucose metabolism. RESULTS: Overexpression of edd and eda in E...
2016: Biotechnology for Biofuels
Parveen Kumari, B S Khatkar
Phenolic content, antioxidant activities and antimicrobial activities of methanolic, ethanolic and ethyl acetate extracts of five different varieties of aonla (Emblica officinalis) fruits as well their powders were evaluated. Total polyphenolic content in fresh aonla fruit extracts varied from 70.6 to 159.4 mg GAE/g and their EC 50 (effective concentration) values for antioxidant activity ranged from 46.72 to 359.7 µg/ml. Significant varietal difference were observed in antioxidant activity of the extracts of fresh aonla fruit and powder...
July 2016: Journal of Food Science and Technology
Juan Manuel Bello-López, Facundo Hernández-Rodríguez, Julieta Rojo-Medina
INTRODUCTION: γ-radiation is a method that was originally designed for inactivation of T lymphocytes in blood and blood components in order to prevent transfusion associated-graft versus host disease (TA-GVHD). Klebsiella pneumoniae, Escherichia coli, Enterococcus faecium and Staphylococcus epidermidis strains are important pathogens in blood banks since they have been related to post-transfusional sepsis. This study was conducted to demonstrate that γ-radiation is effective in reducing the viability of bacteria in platelet concentrates (PC)...
September 29, 2016: Transfusion and Apheresis Science
Menaga Ilangkovan, Ibrahim Jantan, Syed Nasir Abbas Bukhari
BACKGROUND: Phyllanthin found in many Phyllanthus species has various biochemical and pharmacological properties especially on its hepatoprotective effects. However, its effect on the immune system has not been well documented. PURPOSE: In the present study, phyllanthin isolated from Phyllanthus amarus was investigated for its immunosuppressive effects on various cellular and humoral immune responses in Balb/C mice. METHODS: Male mice were treated daily at 20, 40 and 100mg/kg of phyllanthin for 14 days by oral gavage...
November 15, 2016: Phytomedicine: International Journal of Phytotherapy and Phytopharmacology
B X Ke, D M He, H L Tan, H H Zeng, T Yang, B S Li, Y H Liang, L L Lu, J H Liang, Q Huang, C W Ke
Objective: To study the infection status, serotypes, drug resistance and molecular characteristics of Salmonella, Shigella, Vibrio parahemolyticus, enterotoxigenic Escherichia (E.) coli (ETEC), pathogenic E. coli (EPEC), Shiga Toxin producing E. coli (STEC) and Enteroinvasive E. coli (EIEC) collected from diarrhea patients in Guangdong. Methods: The strains of Salmonella, Shigella, V. parahemolyticus and 4 kinds of E. coli isolated from foodborne diseases surveillance during 2013-2014 were collected to conduct serotyping, drug resistance test and pulsed-field gel electrophoresis (PFGE)...
October 10, 2016: Zhonghua Liu Xing Bing Xue za Zhi, Zhonghua Liuxingbingxue Zazhi
Sylwia Wrotek, Krzysztof Domagalski, Tomasz Jędrzejewski, Eliza Dec, Wiesław Kozak
PURPOSE: The aim of our study was to investigate the effect of buthionine sulfoximine (BSO) - a glutathione depletor - on a course of endotoxic fever and IL-1β and IL-6 production. MATERIAL AND METHODS: Male Wistar rats were subjected to intraperitoneal injection of lipopolysaccharide (LPS) from E. coli (50μg/kg, ip) to provoke fever. The level of spleen glutathione, plasma interleukin (IL)-1β, IL-6, and deep body temperature (Tb) were measured. RESULTS: The LPS administration provoked fever (the average Tb was 38...
October 17, 2016: Cytokine
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