scholarly journals ANTIMICROBIAL POTENTIALS OF SOIL FUNGI METABOLITES, MOLECULAR DYNAMICS AND THEIR 3D PROTEIN STRUCTURAL PREDICTION USING BIOINFORMATICS TOOL

Author(s):  
MAJOLAGBE O. N. ◽  
AINA D. A. ◽  
OMOMOWO I. O. ◽  
THOMAS A.

Objective: To determine the antimicrobial potentials of secondary metabolite of soil fungi and predict their 3D structure and molecular identity. Methods: Pure soil fungi were isolated from soil samples and cultured under submerged fermentation (Smf) for their metabolites using Potato Dextrose Agar and Broth. The secondary metabolites of the isolated fungi were obtained intracellularly after 21 d of incubation in a rotary shaker incubator. The antimicrobial potentials of the metabolites were investigated against four (4) clinical isolates, namely: Staphylococcus aureus, Klebsiella spp, Candida albicans and Escherichia coli. These soil fungi were further characterized to the molecular level and their evolutionary relationships established using bioinformatics tools. Protein structure of each of the fungi isolates was predicted using PHYRE-2. Results: Out of all the soil fungi isolated, the metabolite of Aspergillus aculeatus showed the highest antimicrobial activities against Staphylococcus aureus (23.00±2.34 mm), Escherichia coli (9.00±1.44 mm) and Klebsiella spp (24.00±3.45 mm). The 3D protein structure predicted showed that each of the organisms consists of different amino-acid compositions such as: serine, tyrosine, proline, arginine, glycine, phenylalanine leucine with other notable biological properties. Conclusion: The work revealed that secondary metabolites of the isolated fungi carry an important role in combating infectious agents thereby, providing roadmaps for the biosynthesis of many synthetic and semi-synthetic drugs and bio-products which are environmentally friendly.

Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1588 ◽  
Author(s):  
Bi Foua Claude Alain Gohi ◽  
Hong-Yan Zeng ◽  
Xiao-Ju Cao ◽  
Kai-Min Zou ◽  
Wenlin Shuai ◽  
...  

Hybrid nano-supra molecular structured materials can boost the functionality of nano- or supra-molecular materials by providing increased reactivity and conductivity, or by simply improving their mechanical stability. Herein, the studies in materials science exploring hybrid systems are investigated from the perspective of two important related applications: healthcare and food safety. Interfacing phase strategy was applied, and ZnAl layered double hydroxide-chitosan hybrids, prepared by the urea method (U-LDH/CS), were successfully synthesized under the conditions of different chitosan(CS) concentrations with a Zn/Al molar ratio of 5.0. The structure and surface properties of the U-LDH/CS hybrids were characterized by X-ray diffraction (XRD), Fourier-transform infrared spectrometer(FTIR), scanning electronmicroscopy (SEM), ultravioletvisible (UV-Vis), and zero point charge (ZPC) techniques, where the effect of CS concentration on the structure and surface properties was investigated. The use of the U-LDH/CS hybrids as antimicrobial agents against Escherichia coli, Staphylococcus aureus, and Penicillium cyclopium was investigated in order to clarify the relationship between microstructure and antimicrobial ability. The hybrid prepared in a CS concentration of 1.0 g∙L−1 (U-LDH/CS1) exhibited the best antimicrobial activity and exhibited average inhibition zones of 24.2, 30.4, and 22.3mm against Escherichia coli, Staphylococcus aureus, and Penicillium cyclopium, respectively. The results showed that the appropriate addition of CS molecules could increase antimicrobial ability against microorganisms.


2018 ◽  
Author(s):  
Nathan J. Rollins ◽  
Kelly P. Brock ◽  
Frank J. Poelwijk ◽  
Michael A. Stiffler ◽  
Nicholas P. Gauthier ◽  
...  

SummaryHigh-throughput experimental techniques have made possible the systematic sampling of the single mutation landscape for many proteins, defined as the change in protein fitness as the result of point mutation sequence changes. In a more limited number of cases, and for small proteins only, we also have nearly full coverage of all possible double mutants. By comparing the phenotypic effect of two simultaneous mutations with that of the individual amino acid changes, we can evaluate epistatic effects that reflect non-additive cooperative processes. The observation that epistatic residue pairs often are in contact in the 3D structure led to the hypothesis that a systematic epistatic screen contains sufficient information to identify the 3D fold of a protein. To test this hypothesis, we examined experimental double mutants for evidence of epistasis and identified residue contacts at 86% accuracy, including secondary structure elements and evidence for an alternative all-α-helical conformation. Positively epistatic contacts – corresponding to compensatory mutations, restoring fitness – were the most informative. Folded models generated from top-ranked epistatic pairs, when compared with the known structure, were accurate within 2.4 Å over 53 residues, indicating the possibility that 3D protein folds can be determined experimentally with good accuracy from functional assays of mutant libraries, at least for small proteins. These results suggest a new experimental approach for determining protein structure.


2020 ◽  
Vol 21 (2) ◽  
pp. 106-113
Author(s):  
D.K. Adeyemi ◽  
A.O. Adeluola ◽  
M.J. Akinbile ◽  
O.O. Johnson ◽  
G.A. Ayoola

Background: Nanotechnology offers an advantage as a green route for synthesis of metal nanoparticles (NPs) with plant extracts as capping agent. Spondias mombin is a fruit-bearing tree and its leaf extracts have been reported to possess anxiolytic, hypoglycaemic, antiepileptic, antipsychotic, sedative, antioxidant, and antimicrobial properties. The objective of the study is to determine the antibacterial potential of a simple non-toxic product of green synthesis of metallic (Ag, Zn and Cu) nanoparticles using the leaf of Spondias mombin aqueous extracts (SMAE) as a reducing and capping agents of the metal ions.Methodology: Nanoparticles were characterized by UV visible spectrophotometeric analysis, Fourier Transform Infra-Red (FT-IR) spectrophotometer and scanning electron microscope (SEM). Antimicrobial activities of synthesized NPs against Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa were determined by agar well diffusion technique.Results: The synthesized NPs varied in colour from dark brown to green and appears dominantly spherical, occasionally rod or triangular shaped with size ranging from 65-90 nm. UV spectroscopy absorption spectra of Ag, Zn and Cu NPs had absorbance peak at 267, 262 and 765 nm respectively. FT-IR spectrometry of Zn NP, Cu NP, and SMAE gave wave number ranging from 895.71-3320.67, 747.02-3225.45 and 658.25-3674.49 respectively. FT-IR analysis showed that SMAE acted as reducing and stabilizing agent while the NPs exhibited lower energy absorption band when compared to the plant extract. The NPs demonstrated higher antimicrobial activities against S. aureus than Ps. aeruginosa and E. coli. The antimicrobial activity was higher with copper NP than Ag and Zn NPs, and also higher than SMAE.Conclusion: The result from this study presents an indication for an alternative means for development of novel antimicrobial agents for clinical and biotechnological applications.Keywords: synthesis, nanoparticles, FT-IR, UV-visible spectrophotometry, antibacterial activitiesFrench Title: Synthèse verte de nanoparticules d'Ag, de Zn et de Cu à partir d'extrait aqueux de feuilles de Spondias mombin et évaluation de leur activité antibactérienneContexte: La nanotechnologie offre un avantage en tant que voie verte pour la synthèse de nanoparticules métalliques (NP) avec des extraits de plantes comme agent de coiffage. Spondias mombin est un arbre fruitier et ses extraits de feuilles possèdent des propriétés anxiolytiques,  hypoglycémiques, antiépileptiques, antipsychotiques, sédatives,  antioxydantes et antimicrobiennes. L’objectif de l’étude est de déterminer le potentiel antibactérien d’un simple produit non toxique de synthèse verte de nanoparticules métalliques (Ag, Zn et Cu) à l’aide de la feuille d’extraits aqueux de Spondias mombin (SMAE) en tant qu’agent réducteur et coiffant de la ions métalliques.Méthodologie: Les nanoparticules ont été caractérisées par analyse  spectrophotométrique UV visible, spectrophotomètre à transformée de Fourier infrarouge (FT-IR) et microscope électronique à balayage (MEB). Lesactivités antimicrobiennes de NP synthétisées contre Escherichia coli, Staphylococcus aureus et Pseudomonas aeruginosa ont été déterminées par une technique de diffusion sur puits d’agar.Résultats: Les NP synthétisés ont une couleur allant du brun foncé au vert et apparaissent principalement sphériques, parfois en bâtonnets ou en triangles, avec des tailles allant de 65 à 90 nm. Les spectres  d'absorption par spectroscopie UV des NP Ag, Zn et Cu présentaient des pics  d'absorbance à 267, 262 et 765 nm respectivement. La spectrométrie FT-IR de Zn NP, Cu NP et SMAE a donné un nombre d'onde allant de 895,71 à 3320,67, 747,02 à 3225,45 et 658,25 à 3674,49 respectivement. L'analyse FT-IR a montré que le SMAE agissait en tant qu'agent réducteur et  stabilisant, alors que les NP présentaient une bande d'absorption d'énergie inférieure à celle de l'extrait de plante. Les NP ont démontré des activités antimicrobiennes plus élevées contre S. aureus que Ps. aeruginosa et E. coli. L'activité antimicrobienne était plus élevée avec les NP en cuivre que dans les NP Ag et Zn, et également supérieure à celle du SMAE.Conclusion: le résultat de cette étude présente une indication d'un autre moyen de développement de nouveaux agents antimicrobiens pour des applications cliniques et biotechnologiques.Mots-clés: synthèse, nanoparticules, FT-IR, spectrophotométrie UV-visible, activités antibactériennes 


2018 ◽  
Vol 11 (1) ◽  
pp. 174-178
Author(s):  
Muhammad Saleh Salga ◽  
Sani Sabo

A series of four mixed ligand complexes synthesized by reacting benzoylacetone and salicylaldehyde with different metal chlorides in ethanolic medium, were tested for their antimicrobial studies and indicated that the compounds are active against microorganisms used (Escherichia coli, Staphylococcus aureus, and Candida albicans) when compared with the activity of the reference or standard drugs (Erythromycin and Suptrin).Keywords: Antimicrobial, Synthesis, Ligands, Complexes


1994 ◽  
Vol 302 (2) ◽  
pp. 535-538 ◽  
Author(s):  
J Alvarez-Bravo ◽  
S Kurata ◽  
S Natori

Previously, we identified a core undecapeptide of sapecin B having antimicrobial activity. Based on the structure of this peptide, we systematically synthesized peptides consisting of terminal basic motifs and internal oligo-leucine sequences and examined their antimicrobial activities. Of these peptides, RLKLLLLLRLK-NH2 and KLKLLLLLKLK-NH2 were found to have potent microbicidal activity against Staphylococcus aureus, Escherichia coli, methicillin-resistant S. aureus and Candida albicans in liquid medium. We also synthesized the D-enantiomer of KLKLLLLLKLK-NH2. This enantiomer was resistant to tryptic digestion and persisted longer in the culture medium, showing greater antimicrobial activity than the original peptide.


2020 ◽  
pp. 1-3
Author(s):  
Dunjia Wang ◽  
Dan Wang ◽  
Dunjia Wang ◽  
Heng Lyu ◽  
Hengyi Du ◽  
...  

Eight novel containing sulfur heterocyclic curcumins were synthesized and characterized by 1H-NMR, FTIR and MS spectroscopy. Their antimicrobial activities against Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Aspergillus niger were also tested for MIC by using serial tube dilution method. The results showed that the antimicrobial activities of synthesized curcumin derivatives were better than curcumin. Especially, the compound 4-(1,3-dithiolan-2-ylidene)-1,7-di(thiophen-2-yl) hepta-1,6-diene-3,5- dione (2g) exhibited excellent the antimicrobial activities among these curcumin derivatives.


Food Research ◽  
2020 ◽  
Vol 4 (S5) ◽  
pp. 1-10
Author(s):  
N.A. Abdullah ◽  
W.Z.W.M. Zain ◽  
H.A. Hamid ◽  
N.W. Ramli

This review is aimed to present information on the properties of Piperaceae which can be potentially used as a biopesticide. The chemical compounds involved in were different as each species consist of different amount of secondary metabolites which then leads to different properties. In recent years, several reports have been published regarding the composition and the biological activities of the essential oils of Piper species. These studies have highlighted the existence of marked chemical differences among oils extracted from different species or varieties. Analysis of volatile constituents from Piperaceae species has revealed the presence of monoterpenes, sesquiterpenes and arylpropanoids that have shown interesting biological properties including cytotoxic, fungistatic, insecticide, molluscicidal, antioxidant and antimicrobial activities. Essential oils are natural complex secondary metabolites characterized by strong odour, volatility and have generally lower density than water. Due to their volatility, essential oils are environmentally non-persistent. On top of that, essential oils are ‘generally recognized as safe’ by the United States Food and Drug Administration (FDA). Since technology has become more advanced, people started to replace synthetic pesticide with bio-pesticide. The demand for EO has increased as it has biological properties that can be used to replace synthetic pesticide


2021 ◽  
Vol 46 (2) ◽  
Author(s):  
O. B Daramola ◽  
A. A Olajide ◽  
N Torimiro ◽  
R. C George

Wound infections have become life threatening as a result of treatment failures caused by multi-drug resistant pathogens. The search for newer compounds potent against antibiotic resistant bacteria associated with wounds is crucial. Hence this study investigated the application of antibacterial photodynamic therapy using meso tetra-(4-phenyl) porphyrin (TPP), metallated with zinc, tin and silver (ZnTPP, SnTPP and AgTPP), meso tetra-(4-sulphonatephenyl) porphyrin (TPPS) and the corresponding metallo meso tetra-(4-sulphonatephenyl) porphyrin (MTPPS) as photosensitizers. The in-vitro toxicity and photo-toxicity properties on four chronic wound colonizing multi-drug resistant bacterial strains: Staphylococcus aureus, Klebsiella sp., Proteus sp., and Escherichia coli were assessed using agar well diffusion method. Photo-toxicity of the compounds was investigated using 100 Watt tungsten lamp. Inhibitory activity of porphyrins tested against these bacterial strains showed Staphylococcus aureus to have both lowest (11±0.0 mm) and highest (33±1.1 mm) susceptibility to SnTPPS and ZnTPPS respectively. The sequence of data also showed appreciable improvement in the antimicrobial activities of five metalloporphyrins (SnTPP, AgTPP, ZnTPPS, SnTPPS and AgTPPS) exposed to light rays than when tested against bacterial strains in dark condition. ZnTPPS exhibited the best activity with improved photo-toxic activities against all bacterial strains (Staphylococcus aureus 33±1.1 mm, Klebsiella sp. 32±0.7 mm, Proteus sp. 28±0.7 mm and Escherichia coli 30±1.4 mm) examined in this study.


2020 ◽  
pp. 5-9
Author(s):  
Partha Paul ◽  
Md. Zahid Al Hasan ◽  
Arup Kumar ◽  
Mohammad Hasan Chowdhury ◽  
Md. Jayed Chowdhury ◽  
...  

The study was done to isolate Klebsiella spp., Staphylococcus aureus, Escherichia coli & Pseudomonas spp. from raw milk, processed milk (powdered milk & ultra-high-temperature milk) and dairy products (mango milk, and ice cream). During 3 months’ time span of study, a total of ten samples were gathered where eight of the samples powdered milk (2), ultra-high-temperature milk (2), ice cream (2) & mango milk (2) were gathered from different places of Bangladesh & other 2 samples (raw milk) were collected from a cattle farm & individual households in & around Noakhali city. The samples were gathered under aseptic safety measures and were followed by plating on non-selective media (Nutrient broth) & selective media (Mannitol Salt Agar & Macconkey agar). The presumptive Klebsiella spp., Staphylococcus aureus, Escherichia coli & Pseudomonas spp. isolates were identified by biochemical tests. Analysis of the result discovered that out of a total of 10 samples; raw milk (2), processed milk i.e. powdered milk (2), ultra-high-temperature milk (2) and dairy products i.e. mango milk (2) and ice cream (2) resulted in the isolation of 8 isolates (2.5%) of S. aureus, (12.5%) of Klebsiella spp., (2.5%) of Pseudomonas spp. & (2.5%) of Escherichia coli. Results recommended a probability of potential public health threat of Staphylococcus aureus, Klebsiella spp., Escherichia coli & Pseudomonas spp. resulting from contamination of milk and dairy products with pathogenic microorganisms is mainly due to unhygienic practices and conditions in the handling, production, and processing.


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