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Aleksandra Małachowska, Paweł Olszewski
BACKGROUND: Transcriptional control of gene expression is a widely utilized regulatory mechanism in synthetic biology, biotechnology and recombinant protein production. It is achieved by utilization of naturally occurring promoters responding to nutrients or chemicals. Despite their regulatory properties, these promoters often possess features which diminish their utility for biotechnology. High basal expression level and low induction ratio can be removed using genetic engineering techniques, although this process is often laborious and time-consuming...
March 13, 2018: Microbial Cell Factories
Levan Ninua, David Tarkhnishvili, Elguja Gvazava
Current taxonomy of western Eurasian trout leaves a number of questions open; it is not clear to what extent some species are distinct genetically and morphologically. The purpose of this paper was to explore phylogeography and species boundaries in freshwater and anadromous trout from the drainages of the Black and the Caspian Seas (Ponto-Caspian). We studied morphology and mitochondrial phylogeny, combining samples from the western Caucasus within the potential range of five nominal species of trout that are thought to inhabit this region, and using the sequences available from GenBank...
March 2018: Ecology and Evolution
Wafa Hassen, Mohamed Neifar, Hanene Cherif, Afef Najjari, Habib Chouchane, Rim C Driouich, Asma Salah, Fatma Naili, Amor Mosbah, Yasmine Souissi, Noura Raddadi, Hadda I Ouzari, Fabio Fava, Ameur Cherif
A number of Pseudomonas strains function as inoculants for biocontrol, biofertilization, and phytostimulation, avoiding the use of pesticides and chemical fertilizers. Here, we present a new metabolically versatile plant growth-promoting rhizobacterium, Pseudomonas rhizophila S211, isolated from a pesticide contaminated artichoke field that shows biofertilization, biocontrol and bioremediation potentialities. The S211 genome was sequenced, annotated and key genomic elements related to plant growth promotion and biosurfactant (BS) synthesis were elucidated...
2018: Frontiers in Microbiology
Rohita Sinha, Lisa A Weissenburger-Moser, Jennifer L Clarke, Lynette M Smith, Art J Heires, Debra J Romberger, Tricia D LeVan
Chronic obstructive pulmonary disease (COPD) is an inflammatory disorder characterized by incompletely reversible airflow obstruction. The complexity of the lung microbial community in COPD patients has been highlighted in recent years. Evidence suggests that transplantation, medications, age, and disease severity influence microbial community membership. However, the dynamics of the lung microbiome in stable COPD patients remain poorly understood. In this study, we completed a longitudinal 16S ribosomal RNA survey of the lung microbiome on replicate sputum samples collected from 4 former smokers with COPD (Stage 2) within a 2-day time period...
2018: PloS One
Chunjuan He, Yirui Yang, Renfei Zhao, Jingyao Qu, Lan Jin, Lili Lu, Li Xu, Min Xiao
Levansucrases, which belong to the glycoside hydrolase family 68 (GH68), synthesize β (2-6)-linked fructan levan with sucrose as substrate. We described the use of a levansucrase (Bl_SacB) from Bacillus licheniformis 8-37-0-1 for catalysis of fructosyl transfer to obtain high levan yield previously. In the present study, six variants (Y246A, N251A, K372A, R369A, R369S, and R369K) were constructed through sequence alignment and structural analysis to explore the synthesis mechanism of Bl_SacB. The selected residues were predicted to localize to the substrate-entering channel of the active cavity and close to or remote from the catalytic triad...
March 1, 2018: Applied Microbiology and Biotechnology
Dawei Ni, Wei Xu, Yuxiang Bai, Wenli Zhang, Tao Zhang, Wanmeng Mu
Levan, a versatile fructan, possesses promising prospects for application in the food and pharmaceutical industries and in many other fields due to the superior physicochemical properties and physiological functions of this fructan. In this study, a thermostable levansucrase was identified from Lactobacillus reuteri LTH5448. This enzyme shared higher identity with reported inulosucrases than levansucrases but, unexpectedly, yielded a levan-type fructan. Structural analysis of the produced polysaccharide revealed that the glycosidic bonds were β-(2, 6) linkages, and the average molecular weight was 3...
February 6, 2018: International Journal of Biological Macromolecules
Monica M Vasquez, Duane L Sherrill, Tricia D LeVan, Wayne J Morgan, Joseph H Sisson, Stefano Guerra
Alcohol intake has been inconsistently associated with lung function levels in cross-sectional studies. The goal of our study was to determine whether longitudinally assessed light-to-moderate alcohol intake is associated with levels and decline of lung function. We examined data from 1333 adult participants in the population-based Tucson Epidemiological Study of Airway Obstructive Disease. Alcohol intake was assessed with four surveys between 1972 and 1992. Subjects who completed at least two surveys were classified into longitudinal drinking categories ("never", "inconsistent", or "persistent drinker")...
September 1, 2017: Alcohol
Tiago D Gomes, Sofia G Caridade, Maria P Sousa, Sara Azevedo, Muhammed Y Kandur, Ebru T Öner, Natália M Alves, João F Mano
This work is the first reporting the use of layer-by-layer to produce adhesive free-standing (FS) films fully produced using natural-based macromolecules: chitosan (CHI), alginate (ALG) and sulfated levan (L-S). The deposition conditions of the natural polymers were studied through zeta potential measurements and quartz crystal microbalance with dissipation monitoring analysis. The properties of the FS films were evaluated and compared with the control ones composed of only CHI and ALG in order to assess the influence of levan polysaccharide introduced in the multilayers...
January 26, 2018: Acta Biomaterialia
Matthew R Janes, Jingchuan Zhang, Lian-Sheng Li, Rasmus Hansen, Ulf Peters, Xin Guo, Yuching Chen, Anjali Babbar, Sarah J Firdaus, Levan Darjania, Jun Feng, Jeffrey H Chen, Shuangwei Li, Shisheng Li, Yun O Long, Carol Thach, Yuan Liu, Ata Zarieh, Tess Ely, Jeff M Kucharski, Linda V Kessler, Tao Wu, Ke Yu, Yi Wang, Yvonne Yao, Xiaohu Deng, Patrick P Zarrinkar, Dirk Brehmer, Dashyant Dhanak, Matthew V Lorenzi, Dana Hu-Lowe, Matthew P Patricelli, Pingda Ren, Yi Liu
KRASG12C was recently identified to be potentially druggable by allele-specific covalent targeting of Cys-12 in vicinity to an inducible allosteric switch II pocket (S-IIP). Success of this approach requires active cycling of KRASG12C between its active-GTP and inactive-GDP conformations as accessibility of the S-IIP is restricted only to the GDP-bound state. This strategy proved feasible for inhibiting mutant KRAS in vitro; however, it is uncertain whether this approach would translate to in vivo. Here, we describe structure-based design and identification of ARS-1620, a covalent compound with high potency and selectivity for KRASG12C ...
January 25, 2018: Cell
Levan Jibuti, Walter Zimmermann, Salima Rafaï, Philippe Peyla
Micro-organisms usually can swim in their liquid environment by flagellar or ciliary beating. In this numerical work, we analyze the influence of flagellar beating on the orbits of a swimming cell in a shear flow. We also calculate the effect of the flagellar beating on the rheology of a dilute suspension of microswimmers. A three-dimensional model is proposed for Chlamydomonas Reinhardtii swimming with a breaststroke-like beating of two anterior flagella modeled by two counter-rotating fore beads. The active swimmer model reveals unusual angular orbits in a linear shear flow...
November 2017: Physical Review. E
Fabiola Aguilera, Levan Tsamalaidze, Massimo Raimondo, Ruchir Puri, Horacio J Asbun, John A Stauffer
BACKGROUND/AIMS: The operative management of groove pancreatitis (GP) is still a matter of controversy and pancreaticoduodenectomy (PD) can be a high-risk procedure for patients. The aim of this study was to report our 9-year experience of surgical resection for GP and to review relevant literature. METHODS: A retrospective review of patients undergoing pancreatectomy for GP from August 1, 2008, through May 31, 2017 was performed. Patients with clinical, radiologic, and final pathologic confirmation of GP were included...
January 18, 2018: Digestive Surgery
Giorgi Chaladze, Levan Kalatozishvili, Zurab Janiashvili, Giorgi Bakuradze
A new species of ground beetles (Coleoptea: Carabidae) belonging to the subgenus Aphaonus Reitter, 1887 (genus Pterostichus Bonelli, 1810) is described, based on two specimens collected from the sacred grove of Khevsha (Eastern Georgia).
October 3, 2017: Zootaxa
C M Romero, P V Martorell, A Gómez López, C G Nieto Peñalver, S Chaves, M Mechetti
Biocatalysis for industrial application is based on the use of enzymes to perform complex transformations. However, these systems have some disadvantage related to the costs of the biocatalyst. In this work, an alternative strategy for producing green immobilized biocatalysts based on biofilm was developed.A study of the rheological behavior of the biofilm from Bacillus sp. Mcn4, as well as the determination of its composition, was carried out. The dynamic rheological measurements, viscosity (G") and elasticity (G') module, showed that the biofilm presents appreciable elastic components, which is a recognized property for enzymes immobilization...
February 1, 2018: Colloids and Surfaces. B, Biointerfaces
Pavel Tchelidze, Aassif Benassarou, Hervé Kaplan, Marie-Françoise O'Donohue, Laurent Lucas, Christine Terryn, Levan Rusishvili, Giorgi Mosidze, Nathalie Lalun, Dominique Ploton
The nucleolus produces the large polycistronic transcript (47S precursor) containing the 18S, 5.8S and 28S rRNA sequences and hosts most of the nuclear steps of pre-rRNA processing. Among numerous components it contains condensed chromatin and active rRNA genes which adopt a more accessible conformation. For this reason, it is a paradigm of chromosome territory organization. Active rRNA genes are clustered within several fibrillar centers (FCs), in which they are maintained in an open configuration by Upstream Binding Factor (UBF) molecules...
2017: PloS One
Sidra Shaheen, Afsheen Aman, Shah Aliul Qader, Nadir Naveed Siddiqui
The industrial utilization of enzymes requires the high yield of enzyme production for the synthesis of polymers by microorganisms. Therefore, it is necessary to optimize different production parameters of levansucrase in order to increase its industrial applications. Zymomonas mobilis KIBGE-IB14 was considered as a promising candidate for the large scale production of levan among wide range of microorganisms. The current investigation is aimed to optimize the production parameters of levansucrase by Z. mobilis KIBGE-IB14 isolated from molasses...
November 2017: Pakistan Journal of Pharmaceutical Sciences
Wenyue Zhan, Lijin Jin, Jiao Jiao, Xi Zhang, Yan Zhang, Haiyan Zhao, Mingxiang Liang
Inulinases from microorganisms have been extensively studied for their role in the production of fructose from fructan. Fructan can also be hydrolyzed by plant fructan exohydrolases (FEHs), but these enzymes have not been used to produce fructose commercially. Two Ht1-FEHs (Ht1-FEH I and Ht1-FEH II) were recently characterized in Jerusalem artichoke. In this study, we cloned the third member of the Ht1-FEH family in Jerusalem artichoke (i.e., Ht1-FEH III). When heterologously expressed in Pichia pastoris X-33, Ht1-FEH III not only demonstrated hydrolysis activity towards β (2, 1)-linked fructans and β (2, 6)-linked levan, but also towards sucrose...
March 2018: International Journal of Biological Macromolecules
Sujan Timilsina, Gerald V Minsavage, James Preston, Eric A Newberry, Matthews L Paret, Erica M Goss, Jeffrey B Jones, Gary E Vallad
An unusual fluorescent pseudomonad was isolated from tomato exhibiting leaf spot symptoms similar to bacterial speck. Strains were fluorescent, oxidase- and arginine-dihydrolase-negative, elicited a hypersensitive reaction on tobacco and produced a soft rot on potato slices. However, the strains produced an unusual yellow, mucoid growth on media containing 5 % sucrose that is not typical of levan. Based on multilocus sequence analysis using 16S rRNA, gap1, gltA, gyrB and rpoD, these strains formed a distinct phylogenetic group in the genus Pseudomonas and were most closely related to Pseudomonas viridiflava within the Pseudomonassyringae complex...
November 17, 2017: International Journal of Systematic and Evolutionary Microbiology
Taliah Schmitt, Samer Jabbour, Rani Makhoul, Warren Noel, Anne-Sophie Reguesse, Philippe Levan
BACKGROUND: An often neglected part of the lower body lift procedure is the gluteal region. The objective of this study is to classify the massive weight loss (MWL) patients undergoing a body lift procedure and provide a safe, standardized approach for gluteal augmentation. METHODS: A retrospective review of all body lift procedures performed between January 2012 and January 2017 was conducted. Patients undergoing a lower body lift with or without gluteal augmentation were included for analysis...
November 8, 2017: Plastic and Reconstructive Surgery
Levan Tkavadze, Richard R Brey, John Dudgeon
Analyzing uranium isotopic and activity ratios can give valuable information for hydrologic and environmental studies such as insights to weathering processes, estimating water mixing ratios, and identifying water sources. The authors employed an inductively coupled plasma mass spectrometer (ICP-MS) to perform environmental level concentration measurements of isotopic uranium on 380 groundwater samples from various locations within the state of Idaho. The U:U uranium activity ratios (UAR) for these samples range between 0...
November 10, 2017: Health Physics
Wei Xu, Qian Liu, Yuxiang Bai, Shuhuai Yu, Tao Zhang, Bo Jiang, Wanmeng Mu
A high molecular weight levan was produced by a novel levansucrase and some properties of this polymer were investigated. The levan exhibited a poroid microstructure as well as series of individual ellipsoidal or spheroidal particles. The weight-average molecular weight (M¯w) of the levan was determined to be 1.41×10(8)Da. In a 0.1% solution, the levan showed a mean diameter of 176nm, while in a 1% solution the diameter was 182nm. The decomposition temperature was determined to be 216.67°C, with an endothermic peak at 147...
November 10, 2017: International Journal of Biological Macromolecules
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