scholarly journals First Insight into the Diversity and Antibacterial Potential of Psychrophilic and Psychotrophic Microbial Communities of Abandoned Amber Quarry

2021 ◽  
Vol 9 (7) ◽  
pp. 1521
Author(s):  
Margarita Shevchenko ◽  
Stanislav Sukhikh ◽  
Olga Babich ◽  
Svetlana Noskova ◽  
Svetlana Ivanova ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Bacterial Biofilms ◽  
Cellulolytic Activity ◽  
Antimicrobial Compounds ◽  
Natural Habitats ◽  
The Matrix ◽  
Kaliningrad Region ◽  
Dominant Bacteria ◽  
Insight Into ◽  
Antibacterial Potential

Natural habitats, including extreme ones, are potential sources of new antimicrobial compound producers, such as bacteriocins and enzymes, capable of degrading the matrix polysaccharides of bacterial biofilms. This study aimed to investigate biodiversity and evaluate the antibacterial potential of psychrophilic and psychrotrophic microbial communities of the flooded Walter amber quarry (Kaliningrad region, Russia). As a result of 16S rDNA high-throughput profiling, 127 genera of bacteria belonging to 12 phyla of bacteria were found in sediment samples: Acidobacteria sp., Actinobacteria sp., Armatimonadetes sp., Bacteroidetes sp., Chloroflexi sp., Cyanobacteria sp., Firmicutes sp., Gemmatimonadetes sp., Planctomycetes sp., Proteobacteria sp., Tenericutes sp., and Verrucomicrobia sp. The dominant bacteria groups were the families Ruminococcaceae and Lachnospiraceae, belonging to the order Clostridiales phylum Firmicutes. Analysis of enrichment cultures obtained from sediments showed the presence of antibacterial and cellulolytic activity. It seems likely that the bacteria of the studied communities are producers of antimicrobial compounds and have the potential for biotechnological use.

scholarly journals INHIBITION OF PYOCYANIN PRODUCTION IN PSEUDOMONAS AERUGINOSA BY NATURAL ANTIMICROBIAL COMPOUNDS FROM HERBAL EXTRACTS

2017 ◽  
Vol 10 (6) ◽  
pp. 389
Author(s):  
Preeti Jain ◽  
Suman Kumari ◽  
Ashish Malik
Keyword(s):  
Methanol Extract ◽  
Growth Inhibitor ◽  
Dilution Method ◽  
Antimicrobial Compounds ◽  
Herbal Extracts ◽  
Antimicrobial Compound ◽  
Acetone Extracts ◽  
Microbroth Dilution ◽  
Growth Of Bacteria ◽  
Antibacterial Potential

Objective: P. aeruginosa produces a range of metabolites including pyocyanin that enhance its ability to resist antibiotics and becomes capable of surviving adverse conditions.Method: In this report, eight plants (extracted with five solvents) were screened for antibacterial activity against P. aeruginosa by microbroth dilution method. Afterward tested for inhibition of pyocyanin in presence and absence of plant extracts.Result: Among these D. muricata and S. quitoenes exhibited good antibacterial potential. Inhibition of pyocyanin is identified as a potential anti-virulence strategy. Therefore, acetone extract of six plants exhibited MIC ≤3.125mg/ml and methanol extract of three plants exhibited MIC ≤6.25mg/ml were used to check pyocyanin inhibition in P. aeruginosa. In acetone extracts, significant pyocyanin inhibition was found in I. pestigirdis and C. colocynthis. In methanol extracts, C. colocynthis and D. muricata showed considerable pyocyanin inhibition.Conclusion: Overall result indicates that the best antimicrobial compound (growth inhibitor) may not be best inhibitor of pyocyanin biosynthesis or vice-versa. Moreover, I. pestigirdis, C. colocynthis and D. muricata seems to contain compounds which inhibit the growth of bacteria as well as the biosynthesis of pyocyanin. 

scholarly journals Inactivation of pure bacterial biofilms by impaction of aerosolized consumer products containing nanoparticulate metals

2018 ◽  
Vol 5 (2) ◽  
pp. 544-555
Author(s):  
Jennifer Therkorn ◽  
Leonardo Calderón ◽  
Benton Cartledge ◽  
Nirmala Thomas ◽  
Brian Majestic ◽  
...  
Keyword(s):  
Consumer Products ◽  
Bacterial Biofilms ◽  
Nano Silver ◽  
Antibacterial Potential

Nanotechnology-enabled consumer sprays with Ag may have antibacterial potential, but it is not based solely on nano-silver presence and concentration.

Physiological and molecular characterization of compost bacteria antagonistic to soil-borne plant pathogens

2017 ◽  
Vol 63 (5) ◽  
pp. 411-426 ◽  
Author(s):  
Rowida Mohamed ◽  
Emma Groulx ◽  
Stefanie Defilippi ◽  
Tamara Erak ◽  
James T. Tambong ◽  
...  
Keyword(s):  
Plant Pathogens ◽  
Antagonistic Activity ◽  
Antagonistic Bacteria ◽  
Antimicrobial Compounds ◽  
Fusarium Sambucinum ◽  
Inhibitory Compounds ◽  
Antimicrobial Lipopeptides ◽  
Chemical Pesticides ◽  
Insight Into

Disease suppressive composts have the potential to mitigate the risks associated with chemical pesticides. One of the main characteristics responsible for the suppressive nature of composts is their microbiological populations. To gain insight into the determinants responsible for their suppressive effects, we assayed composts to (i) isolate and identify beneficial antagonistic bacteria, (ii) quantify their antifungal and anti-oomycetal activities, (iii) extract inhibitory compounds produced by the bacteria, and (iv) identify antimicrobial lipopeptides produced by these bacteria. The antagonistic bacteria belonged to the genera Arthrobacter, Pseudomonas, Bacillus, Brevibacillus, Paenibacillus, and Rummeliibacillus and had the ability to antagonise the growth of Fusarium sambucinum, Verticillium dahliae, and (or) Pythium sulcatum. These bacteria produced antimicrobial compounds that affected the mycelial growth and (or) conidial germination of the pathogens. Mass spectrometry analyses showed the presence of various antimicrobial lipopeptides in Bacillus and Bacillus-related spp. extracts, demonstrating that they are responsible, at least in part, for the antagonistic activity of the bacteria. Results from this work provide greater insight into some of the biological, biochemical, and physiological determinants of suppressiveness in composts involved in the control of plant pathogens.

scholarly journals Oxidative Folding and Assembly with Transthyretin Are Sequential Events in the Biogenesis of Retinol Binding Protein in the Endoplasmic Reticulum

2008 ◽  
Vol 19 (12) ◽  
pp. 5579-5592 ◽  
Author(s):  
Sundar Rajan Selvaraj ◽  
Vaibhav Bhatia ◽  
Utpal Tatu
Keyword(s):  
Endoplasmic Reticulum ◽  
Binding Protein ◽  
Retinol Binding Protein ◽  
Cross Linking ◽  
Loop Formation ◽  
Oxidative Folding ◽  
Folding Intermediates ◽  
Small Loop ◽  
The Matrix ◽  
Insight Into

Retinol-binding protein (RBP) is secreted out of the cell in its ligand-bound holo-form. The apo-form of RBP is selectively retained within the endoplasmic reticulum (ER) by a mechanism that remains unknown. Using isolated microsomal system, we have recapitulated the biogenesis of RBP involving its oxidative folding and assembly with transthyretin in the ER. In addition to dissecting its pathway of disulfide oxidation, we have analyzed association of its early folding intermediates with ER-chaperones. Our results show that of the three intramolecular disulfides present in RBP (4–160, 70–174, and 120–129) the smallest loop (120–129) was most critical for RBP to fold. Its absence caused RBP to aggregate into an intermolecular disulfide-linked structure. After acquisition of the small loop, formation of one of the two big disulfides (4–160 or 70–174) was sufficient for RBP to acquire a folded state. Using cross-linking in intact microsomes and sedimentation on sucrose gradients, we show that newly synthesized RBP is associated with a complex of chaperones consisting of Grp94, BiP, PDI, and calnexin. The complex was constitutively present in the ER, independent of the presence of folding substrates. RBP dissociated from this complex coincident with the formation of one of the two big disulfide loops, whereas RBP mutant lacking both the large disulfides showed persistent association. While highlighting the matrix-like characteristics of ER in isolated microsomal system our results provide insight into RBP folding and assembly mechanisms that will aid our understanding of its complex secretion properties.

Elements and Materials Improve the FDM Products: A Review

2016 ◽  
Vol 16 ◽  
pp. 33-51 ◽  
Author(s):  
Abduladim Salem Bala ◽  
Saidin bin Wahab ◽  
Mazatusziha binti Ahmad
Keyword(s):  
Matrix Material ◽  
Process Parameter ◽  
Correct Selection ◽  
Complex Environment ◽  
Technology Process ◽  
The Matrix ◽  
Additive Materials ◽  
Insight Into ◽  
Selection Of

This work aims to provide a review of available published literature that explores the opportunities to improve the quality of fused deposit modelling (FDM) products, particularly in medical applications. The paper presents details concerning the basis of the technology, process parameter settings and their responses, and reviews the properties of common FDM engineering/bio-materials and the available methods applied for improving their performance. Based on the researches which have been reviewed, FDM technology works within a complex environment from process parameters. Thus, it can achieve good results only with the proper settings for these parameters according to the properties of the material used. Improving the polymers is essentially based on the correct selection of additive materials, which can particularly enhance the key property/properties in the matrix material. This review provides a brief insight into FDM technology, provides an idea of the process parameter settings, the available materials and ways of modifying their properties to consequently improve the quality of FDM products.

Visualization and Analysis of Surfactant Imbibition Into Oil-Wet Fractured Cores

SPE Journal ◽  
2016 ◽  
Vol 21 (01) ◽  
pp. 101-111 ◽  
Author(s):  
Mohammad Mirzaei ◽  
David A. DiCarlo ◽  
Gary A. Pope
Keyword(s):  
Oil Recovery ◽  
Fractured Reservoirs ◽  
Surfactant Solution ◽  
Ct Scanning ◽  
Recovery Curves ◽  
The Core ◽  
The Matrix ◽  
Insight Into ◽  
Scaling Group ◽  
Better Than

Summary Imbibition of surfactant solution into the oil-wet matrix in fractured reservoirs is a complicated process that involves gravity, capillary, viscous, and diffusive forces. The standard experiment for testing imbibition of surfactant solution involves an imbibition cell, in which the core is placed in the surfactant solution and the recovery is measured vs. time. Although these experiments prove the effectiveness of surfactants, little insight into the physics of the problem is achieved. In this study, we performed water and surfactant flooding into oil-wet fractured cores and monitored the imbibition of the surfactant solution by use of computed-tomography (CT) scanning. From the CT images, the surfactant-imbibition dynamics as a function of height along the core was obtained. Although the waterflood only displaced oil from the fracture, the surfactant solution imbibed into the matrix; the imbibition is frontal, with the greatest imbibition rate at the bottom of the core, and the imbibition decreases roughly linearly with height. Experiments with cores of different sizes showed that increase in either the height or the diameter of the core causes decrease in imbibition and fractional oil-recovery rate. We also perform numerical simulations to model the observed imbibition. On the basis of the experimental measurements and numerical-simulation results, we propose a new scaling group that includes both the diameter and the height of the core. We show that the new scaling groups scale the recovery curves better than the traditional scaling group.

Development of a Simple and Highly Sensitive Microbalance for Measurements of Total Particle Yields in Matrix Assisted Laser Desorption

1992 ◽  
Vol 285 ◽  
Author(s):  
T. Huth-fehre ◽  
A.P. Quist ◽  
S-O. Linder ◽  
B.U.R. Sundqvist
Keyword(s):  
Quartz Crystal ◽  
Laser Desorption ◽  
Laser Desorption Ionization ◽  
Neutral Particles ◽  
Highly Sensitive ◽  
The Matrix ◽  
Total Particle ◽  
Insight Into ◽  
Matrix Assisted Laser ◽  
Matrix Assisted Laser Desorption

ABSTRACTIn order to open a new window for getting insight into the process of matrix assisted laser desorption ionization (MALDI) of biopolymers, a highly sensitive quartz crystal microbalance (QCM) was developed to measure desorption yields of neutral particles. For the matrix substances commonly used the mass resolution of 0.95 ng obtained with the balance corresponds to a detection limit of ∼1012 particles.

scholarly journals Membrane Vesicles: an Overlooked Component of the Matrices of Biofilms

2006 ◽  
Vol 188 (16) ◽  
pp. 5945-5957 ◽  
Author(s):  
Sarah R. Schooling ◽  
Terry J. Beveridge
Keyword(s):  
Structural Characteristics ◽  
Membrane Vesicles ◽  
Growth Conditions ◽  
Model Systems ◽  
Bacterial Biofilms ◽  
Natural Environments ◽  
Gram Negative ◽  
Functional Roles ◽  
Transmission Electron ◽  
The Matrix

ABSTRACT The matrix helps define the architecture and infrastructure of biofilms and also contributes to their resilient nature. Although many studies continue to define the properties of both gram-positive and gram-negative bacterial biofilms, there is still much to learn, especially about how structural characteristics help bridge the gap between the chemistry and physical aspects of the matrix. Here, we show that membrane vesicles (MVs), structures derived from the outer membrane of gram-negative bacteria, are a common particulate feature of the matrix of Pseudomonas aeruginosa biofilms. Biofilms grown using different model systems and growth conditions were shown to contain MVs when thin sectioned for transmission electron microscopy, and mechanically disrupted biofilms revealed MVs in association with intercellular material. MVs were also isolated from biofilms by employing techniques for matrix isolation and a modified MV isolation protocol. Together these observations verified the presence and frequency of MVs and indicated that MVs were a definite component of the matrix. Characterization of planktonic and biofilm-derived MVs revealed quantitative and qualitative differences between the two and indicated functional roles, such as proteolytic activity and binding of antibiotics. The ubiquity of MVs was supported by observations of biofilms from a variety of natural environments outside the laboratory and established MVs as common biofilm constituents. MVs appear to be important and relatively unacknowledged particulate components of the matrix of gram-negative or mixed bacterial biofilms.

Synthesizing Single DOF Linkages Via Transition Linkage Identification

2007 ◽  
Vol 130 (2) ◽  
Author(s):  
Andrew P. Murray ◽  
Michael L. Turner ◽  
David T. Martin
Keyword(s):  
Classification Scheme ◽  
Degree Of Freedom ◽  
Physical Parameters ◽  
Single Degree Of Freedom ◽  
Loop Closure ◽  
Single Degree ◽  
The Matrix ◽  
Comprehensive Classification ◽  
Insight Into ◽  
Selection Of

A linkage is partially classified by identifying those links capable of unceasing and drivable rotation and those that are not. In this paper, we examine several planar single degree-of-freedom linkages to identify all changes to the physical parameters that may alter this classification. The limits on the physical parameters that result in no change in the classification are defined by transition linkages. More rigorously, a transition linkage possesses a configuration at which the matrix defined by the derivative of the loop closure equations with respect to the joint variables loses rank. Transition linkages divide the set of all linkages into different classifications. In the simplest cases studied, transition linkage identification produces a comprehensive classification scheme. In all cases, this identification is used to alter a linkage’s physical parameters without changing its classification and produces insight into the selection of these parameters to produce a desired classification.

scholarly journals Influencers and Major Themes in a Gifted Education Community of Practice on Twitter

2021 ◽  
Author(s):  
Erin Morris Miller ◽  
Jennifer Jolly ◽  
Jacqueline Latz ◽  
Kelsi Listman
Keyword(s):  
Community Of Practice ◽  
Gifted Education ◽  
Past Research ◽  
Sources Of Information ◽  
False Information ◽  
Education Professionals ◽  
Education Community ◽  
The Matrix ◽  
Online Sources ◽  
Insight Into

Twitter is a valuable resource for research because of its potential to provide insight into public opinions as well as identify whom are the most influential sources of information. However, false information spreads easily on Twitter and parents often trust online sources even when those ideas run counter to the information from professionals (Külhaş Çelik et al., 2019). Convergent mixed methods exploratory analysis was used to evaluate the discourse on Twitter regarding gifted education. The results of the quantitative analysis of the matrix of connections using NodeXL Pro indicate that gifted education Twitter is a cohesive network and that the top influencers are organizations and educational consultants. The qualitative analyses suggest that gifted education professionals and parents engage in Twitter in similar ways to what has been described in past research: to share interesting articles and videos, to discuss current issues, promote one’s ideas, and seek opportunities.

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