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Mechanical strain

Lena Barra, Jeroen Sidney Dickschat
Analysis of the volatile terpenes produced by seven fungal strains of the genus Trichoderma by use of a closed-loop stripping apparatus (CLSA) revealed a common production of harzianone, a bioactive, structurally unique diterpenoid consisting of a fused tetracyclic 4,5,6,7-membered ring system. The terpene cyclization mechanism was studied by feeding experiments using selectively 13C- and 2H-labeled synthetic mevalonolactone isotopologues, followed by analysis of the incorporation patterns by 13C-NMR spectroscopy and GC/MS...
September 25, 2017: Chembiochem: a European Journal of Chemical Biology
Susanna Seppälä, St Elmo Wilken, Doriv Knop, Kevin V Solomon, Michelle A O'Malley
A wealth of fungal enzymes has been identified from nature, which continue to drive strain engineering and bioprocessing for a range of industries. However, while a number of clades have been investigated, the vast majority of the fungal kingdom remains unexplored for industrial applications. Here, we discuss selected classes of fungal enzymes that are currently in biotechnological use, and explore more basal, non-conventional fungi and their underexploited biomass-degrading mechanisms as promising agents in the transition towards a bio-based society...
September 21, 2017: Metabolic Engineering
Tony Picoli, Cristina Mendes Peter, João Luíz Zani, Stefanie Bressan Waller, Matheus Gomes Lopes, Kamilla Neutzling Boesche, Gilberto D Ávila Vargas, Silvia de Oliveira Hübner, Geferson Fischer
Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa stand out in veterinary and human medicine for their role in opportunistic infections and their pathogenic mechanisms, including the biofilms formation. It was investigated the antibacterial activity of melittin and antibiofilm of such bacteria. Twelve strains of these microorganisms isolated from bovine milk were used, as well as the strains S. aureus ATCC 12600, E. coli ATCC 8739 and Pseudomonas aeruginosa ATCC 15442. The minimum inhibitory concentrations (MIC) and minimum bactericidal concentration (MBC) were determined by broth microdilution technique...
September 21, 2017: Microbial Pathogenesis
María Ordóñez-Robles, Fernando Santos-Beneit, Antonio Rodríguez-García, Juan F Martín
Phosphate regulation of antibiotic biosynthesis in Streptomyces has been studied due to the importance of this genus as a source of secondary metabolites with biological activity. Streptomyces tsukubaensis is the main producer of tacrolimus (or FK506), an immunosuppressant macrolide that generates important benefits for the pharmaceutical market. However, the production of tacrolimus is under a negative control by phosphate and, therefore, is important to know the molecular mechanism of this regulation. Despite its important role, there are no reports about the Pho regulon in S...
December 2017: Microbiological Research
Kathryn Beabout, Megan D McCurry, Heer Mehta, Akshay Ashok Shah, Kiran Kumar Pulukuri, Stephan Rigol, Yanping Wang, K C Nicolaou, Yousif Shamoo
The continuing rise of multi-drug resistant pathogens has made it clear that in the absence of new antibiotics we are moving toward a 'post-antibiotic' world, in which even routine infections will become increasingly untreatable. There is a clear need for the development of new antibiotics with truly novel mechanisms of action to combat multi-drug resistant pathogens. Experimental evolution to resistance can be a useful tactic for the characterization of the biochemical mechanism of action for antibiotics of interest...
September 23, 2017: ACS Infectious Diseases
Azza H Abd Elwahab, Basma K Ramadan, Mona F Schaalan, Amina M Tolba
BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) is one of the alarmingly rising clinical problems in the 21st century with no effective drug treatment until now. Taurine is an essential amino acid in humans that proved efficacy as a non-pharmacological therapy in a plethora of diseases; however, its impact on NAFLD remains elusive. The aim of the current study is to evaluate the protective mechanism of taurine in experimental steatohepatitis induced by junk food given as cafeteria-diet (CAF-D) in male albino rats...
September 22, 2017: Cellular Physiology and Biochemistry
Ranju Paudyal, Ruth H Barnes, Kimon Andreas G Karatzas
Here it is demonstrated a novel approach in disinfection regimes where specific molecular acid resistance systems are inhibited aiming to eliminate microorganisms under acidic conditions. Despite the importance of the Glutamate Decarboxylase (GAD) system for survival of Listeria monocytogenes and other pathogens under acidic conditions, its potential inhibition by specific compounds that could lead to its elimination from foods or food preparation premises has not been studied. The effects of maleic acid on the acid resistance of L...
February 2018: Food Microbiology
Hani El Kadri, Putu Virgina Partha Devanthi, Tim W Overton, Konstantinos Gkatzionis
Nano-emulsions (typically droplet diameter<1μm) are common in foods, and have been extensively reported to present antimicrobial activity, however, the mechanism is not well defined, and some studies reported no effect. A review of the literature was conducted and revealed strongly contradictory reports regarding the antimicrobial effect of nano-emulsions even in reference to similar microbial species and formulations. Following up, this study aimed to investigate the effect of nano-emulsions on four bacterial species (Staphylococcus epidermidis, Bacillus cereus, Lactobacillus acidophilus and five Escherichia coli strains) possessing different surface charge and hydrophobicity...
November 2017: Food Research International
Ramsey Al-Hakim, Alok Bhatt, James F Benenati
The Indigo Mechanical Thrombectomy System (Penumbra, Inc, Alameda, California) was used to treat 6 patients with submassive pulmonary embolism (PE) and a contraindication to thrombolysis. Systolic pulmonary artery pressure (58.2 mm Hg vs 43.0 mm Hg, P < .05), right ventricular/left ventricular ratio (1.7 vs 1.1, P < .05), Miller index (15.0 vs 9.8, P < 0.01), and CT obstructive index (60.4% vs 47.0%, P < .01) were significantly reduced after mechanical thrombectomy. There were no procedural or periprocedural complications...
October 2017: Journal of Vascular and Interventional Radiology: JVIR
Rami M A Al-Dirini
For cementless femoral stems, there is debate as to whether a collar enhances primary stability and load transfer compared to collarless designs. Finite Element (FE) analysis has the potential to compare stem designs within the same cohort, allowing for subtle performance differences to be identified, if present. Subject-specific FE models of intact and implanted femora were run for a diverse cohort (21 males, 20 females; BMI 16.4-41.2 kg.m(-2) , age 50-80yrs). Collared and collarless versions of Corail® (DePuy Synthes) were sized and positioned using an automated algorithm that aligns the femoral/stem axes, preserves the head-centre location and maximises metaphyseal fit...
September 21, 2017: Journal of Orthopaedic Research: Official Publication of the Orthopaedic Research Society
Qinfeng Rong, Wenwei Lei, Lie Chen, Yongai Yin, Jiajia Zhou, Mingjie Liu
Conductive hydrogels emerge as a fascinating class of stretchable conductive materials that are important for various applications. However, water-based conductive hydrogels inevitably lose elasticity and conductivity at subzero temperatures, which severely limits their practical applications at low temperatures. Here we report anti-freezing conductive organohydrogels by using an H2O/ethylene glycol binary solvent as dispersion medium. Owing to the freezing tolerance of the binary solvent, our organohydrogels exhibit stable flexibility and strain-sensitivity in the temperature range from -55...
September 22, 2017: Angewandte Chemie
Goh Kar Mun, Matthew Dickinson, Christina V Supramaniam
Lignification of the plant cell wall could serve as the first line of defence against pathogen attack, but the molecular mechanisms of virulence and disease between oil palm and Ganoderma boninense is poorly understood. This study presents the biochemical, histochemical, enzymology and gene expression evidences of enhanced lignin biosynthesis in young oil palm as a response to G. boninense (GBLS strain). Comparative studies with control (T1), wounded (T2) and infected (T3) oil palm plantlets showed significant accumulation of total lignin content and monolignol derivatives (syringaldehyde and vanillin)...
September 20, 2017: Physiologia Plantarum
R Benoist, C Chantre, C Capdevielle-Dulac, M Bodet, F Mougel, P A Calatayud, S Dupas, E Huguet, R Jeannette, J Obonyo, C Odorico, J F Silvain, B Le Ru, L Kaiser
Studying mechanisms that drive host adaptation in parasitoids is crucial for the efficient use of parasitoids in biocontrol programs. Cotesia typhae nov. sp. (Fernández-Triana) (Hymenoptera: Braconidae) is a newly described parasitoid of the Mediterranean corn borer Sesamia nonagrioides (Lefebvre) (Lepidoptera: Noctuidae). Braconidae are known for their domesticated bracovirus, which is injected with eggs in the host larva to overcome its resistance. In this context, we compared reproductive success traits of four Kenyan strains of C...
September 22, 2017: Genetica
Ward L Johnson, Danielle Cook France, Nikki S Rentz, William T Cordell, Fred L Walls
The speed of conventional antimicrobial susceptibility testing (AST) is intrinsically limited by observation of cell colony growth, which can extend over days and allow bacterial infections to advance before effective antibiotics are identified. This report presents an approach for rapidly sensing mechanical fluctuations of bacteria and the effects of antibiotics on these fluctuations. Bacteria are adhered to a quartz crystal resonator in an electronic bridge that is driven by a high-stability frequency source...
September 22, 2017: Scientific Reports
Nan Li, Yongtao Zhu, Benjamin R LaFrentz, Jason P Evenhuis, David W Hunnicutt, Rachel A Conrad, Paul Barbier, Connor W Gullstrand, Jack E Roets, Jonathan L Powers, Surashree S Kulkarni, Devon H Erbes, Julio C García, Pin Nie, Mark J McBride
Flavobacterium columnare, a member of the phylum Bacteroidetes, causes columnaris disease in wild and aquaculture-reared freshwater fish. The mechanisms responsible for columnaris disease are not known. Many members of the phylum Bacteroidetes use type IX secretion systems (T9SSs) to secrete enzymes, adhesins, and proteins involved in gliding motility. The F. columnare genome has all of the genes needed to encode a T9SS. gldN, which encodes a core component of the T9SS, was deleted in wild type strains of F...
September 22, 2017: Applied and Environmental Microbiology
Mianmian Chen, Lei Zhang, Sheikheldin A Abdelgader, Li Yu, Juntian Xu, Huochun Yao, Chengping Lu, Wei Zhang
The use of phages as antibacterial agents is limited by their generally narrow host range. The aim of this study was to make a T4-like phage, WG01, obtain the host range of another T4-like phage, QL01, by replacing its host determinant gene region with that of QL01. This process triggered a direct expansion of the WG01 host range. The offspring of WG01 obtained the host ranges of both QL01 and WG01, as well as the ability to infect eight additional host bacteria in comparison to the wildtype strains. WQD had the widest host range; therefore, the corresponding QD fragments could be used for constructing a homologous sequence library...
September 22, 2017: Applied and Environmental Microbiology
Cui-Wei Chu, Bin Liu, Na Li, Shi-Gang Yao, Dan Cheng, Jia-Dong Zhao, Ji-Guo Qiu, Xin Yan, Qin He, Jian He
Thiobencarb is a thiocarbamate herbicide used in rice paddies worldwide. Microbial degradation plays a crucial role in the dissipation of thiobencarb in the environment. However, the physiological and genetic mechanisms underlying thiobencarb degradation remain unknown. In this study, a novel thiobencarb degradation pathway was proposed in Acidovorax sp. T1. Thiobencarb was oxidized and cleaved at the C-S bond, generating diethylcarbamothioic S-acid and 4-chlorobenzaldehyde (4CDA). 4CDA was then oxidized to 4-chlorobenzoic acid (4CBA) and hydrolytically dechlorinated to 4-hydroxybenzoic acid (4HBA)...
September 22, 2017: Applied and Environmental Microbiology
Yuanyuan Cheng, Dandan Wang, Jingyan Gu, Junge Li, Huihui Liu, Fuchuan Li, Wenjun Han
Bifunctional alginate lyases can efficiently degrade alginate comprised of mannuronate (M) and guluronate (G), but their substrate-degrading modes have not been thoroughly elucidated to date. In this study, we present Aly1 as a novel bifunctional endolytic alginate lyase of the genus Flammeovirga The recombinant enzyme showed optimal activity at 50°C and pH 6.0. The enzyme produced unsaturated disaccharide (UDP2) and trisaccharide fractions as the final main alginate digests. Primary substrate-preference tests and further structure identification of various size-defined final oligosaccharide products demonstrated that Aly1 is a bifunctional alginate lyase and prefers G to M...
September 22, 2017: Applied and Environmental Microbiology
Liang Liang, Minliang Liu, Wei Sun
Biological collagenous tissues comprised of networks of collagen fibers are suitable for a broad spectrum of medical applications owing to their attractive mechanical properties. In this study, we developed a noninvasive approach to estimate collagenous tissue elastic properties directly from microscopy images using Machine Learning (ML) techniques. Glutaraldehyde-treated bovine pericardium (GLBP) tissue, widely used in the fabrication of bioprosthetic heart valves and vascular patches, was chosen to develop a representative application...
September 19, 2017: Acta Biomaterialia
Xiao-Man Liu, Yin-Li Zhang, Shu-Yan Ji, Long-Wen Zhao, Wei-Na Shang, Dali Li, Zijiang Chen, Chao Tong, Heng-Yu Fan
The balances of mitochondrial dynamic changes, mitochondrial morphology, and mitochondrial number are critical in cell metabolism. Once disturbed, disorders in these processes generally cause diseases or even death in animals. We performed large-scale genetic screenings in fruit flies and discovered the new gene mitoguardin (miga) that encodes for a mitochondrial outer membrane protein. In order to examine the physiological functions of its mammalian homologs Miga1 and 2, we generated Miga1 and Miga2 single- and double-knockout mouse strains and found that the knockout mice were viable, but the females were subfertile...
August 23, 2017: Endocrinology
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