scholarly journals Antagonistic effect in vitro of three commercial strains of Bacillus sp. against the forest pathogen Diplodia corticola

2021 ◽  
Author(s):  
Emigdio Jordán Muñoz‐Adalia ◽  
Andreu Meijer ◽  
Jonatan C. Campillo‐Brocal ◽  
Carlos Colinas
Keyword(s):  
Antagonistic Effect ◽  
Bacillus Sp ◽  
Forest Pathogen

In vitro Antagonistic Activity of Diverse Bacillus Species Against Cochliobolus sativus (Common Root Rot) of Barley

2020 ◽  
Vol 55 (1) ◽  
pp. 35-42
Author(s):  
M. Harba ◽  
M. Jawhar ◽  
M. I. E. Arabi
Keyword(s):  
16S Rrna Gene Sequencing ◽  
Antagonistic Activity ◽  
Antagonistic Effect ◽  
Cochliobolus Sativus ◽  
Bacillus Species ◽  
Rrna Gene ◽  
Bacillus Sp ◽  
Common Root ◽  
Antagonistic Microorganisms

Antagonistic microorganisms have been used as biological control agents to reduce the use of chemical fungicides in the control of crop diseases. The present work was conducted to determine the antagonistic potential of Bacillus sp. isolates against the soil-borne fungus Cochliobolus sativus, the causal agent of barley common root (CRR) disease. Out of 525 isolates, 40 were showed in vitro antagonistic activity against the virulent C. sativus isolate CRR16. On the basis of 16S rRNA gene sequencing Bacillus sp. isolates are identified as B. atrophaeus, B. subtilis, Paenibacillus polymyxa, B. amyloliquefaciens, B. simplex and B. tequilensis. Results showed that Bacillus sp. had significant (P<0.05) antagonistic activities against the C. sativus where the percentage of radial growth inhibition of the fungi colonies ranged from 59 to 92%, compared to the untreated control. The B. subtilis isolate SY41B had the highest inhibition effect on the vegetative growth zones as compared with the other species isolates. In view of these, our results indicate that the antagonistic effect of the Bacillus sp. isolates may be important contributors as a biocontrol approach that could be employed as a part of integrated CRR management system.

scholarly journals Mutual influence of selenium nanoparticles and FGF2-STAB® on biocompatible properties of collagen/chitosan 3D scaffolds: in vitro and ex ovo evaluation

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Johana Muchová ◽  
Vanessa Hearnden ◽  
Lenka Michlovská ◽  
Lucie Vištejnová ◽  
Anna Zavaďáková ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Metabolic Activity ◽  
Mutual Influence ◽  
Chorioallantoic Membrane ◽  
Antagonistic Effect ◽  
Dermal Fibroblasts ◽  
Selenium Nanoparticles ◽  
Freeze Dried ◽  
Chitosan Scaffolds

AbstractIn a biological system, nanoparticles (NPs) may interact with biomolecules. Specifically, the adsorption of proteins on the nanoparticle surface may influence both the nanoparticles' and proteins' overall bio-reactivity. Nevertheless, our knowledge of the biocompatibility and risk of exposure to nanomaterials is limited. Here, in vitro and ex ovo biocompatibility of naturally based crosslinked freeze-dried 3D porous collagen/chitosan scaffolds, modified with thermostable fibroblast growth factor 2 (FGF2-STAB®), to enhance healing and selenium nanoparticles (SeNPs) to provide antibacterial activity, were evaluated. Biocompatibility and cytotoxicity were tested in vitro using normal human dermal fibroblasts (NHDF) with scaffolds and SeNPs and FGF2-STAB® solutions. Metabolic activity assays indicated an antagonistic effect of SeNPs and FGF2-STAB® at high concentrations of SeNPs. The half-maximal inhibitory concentration (IC50) of SeNPs for NHDF was 18.9 µg/ml and IC80 was 5.6 µg/ml. The angiogenic properties of the scaffolds were monitored ex ovo using a chick chorioallantoic membrane (CAM) assay and the cytotoxicity of SeNPs over IC80 value was confirmed. Furthermore, the positive effect of FGF2-STAB® at very low concentrations (0.01 µg/ml) on NHDF metabolic activity was observed. Based on detailed in vitro testing, the optimal concentrations of additives in the scaffolds were determined, specifically 1 µg/ml of FGF2-STAB® and 1 µg/ml of SeNPs. The scaffolds were further subjected to antimicrobial tests, where an increase in selenium concentration in the collagen/chitosan scaffolds increased the antibacterial activity. This work highlights the antimicrobial ability and biocompatibility of newly developed crosslinked collagen/chitosan scaffolds involving FGF2-STAB® and SeNPs. Moreover, we suggest that these sponges could be used as scaffolds for growing cells in systems with low mechanical loading in tissue engineering, especially in dermis replacement, where neovascularization is a crucial parameter for successful skin regeneration. Due to their antimicrobial properties, these scaffolds are also highly promising for tissue replacement requiring the prevention of infection.

scholarly journals In vitro activity of allicin combined with two antibiotics on intestinal Shigella

2017 ◽  
Vol 6 (1) ◽  
pp. 25-29 ◽  
Author(s):  
Yuchi Jia ◽  
Xiaomei Wu
Keyword(s):  
Intestinal Tract ◽  
Inhibitory Concentration ◽  
Synergistic Effects ◽  
Antagonistic Effect ◽  
Additive Effects ◽  
In Vitro Activity ◽  
Antibacterial Effects ◽  
Combined Application ◽  
Combined Use

Abstract Objective We aimed to evaluate the combined antibacterial effects of allicin in combination with levofloxacin and ceftriaxone on Shigella isolated from the intestinal tract in vitro. Materials and Methods Using a checkerboard design, broth microdilution assay was used to test the effects of the compounds on the organism. We also determined the MIC of the two groups of antibacterial drugs against 30 strains of Shigella and calculated the fractional inhibitory concentration (FIC) index, to judge the combination effect. Result After the combined application of allicin and ceftriaxone the MIC decreased significantly. Distribution of the FIC index was as follows: FIC ≤0.5, accounting for 10%; 0.5< FIC ≤1.0, accounting for 60%; 1 < FIC ≤2, accounting for 30%; FIC >2, percentage is zero. After combined application of allicin and levofloxacin, distribution of FIC index was as follows: FIC≤0.5, ratio is zero; 0.5< FIC ≤1, accounting for 56.7%; 1 < FIC ≤2, accounting for 43.3%; FIC >2, ratio is zero. Conclusion After the combined use of ceftriaxone, levofloxacin, and allicin, most of the tests showed synergistic effects and additive effects on Shigella, while some of them showed no correlation and no antagonistic effect.

scholarly journals Interaction of Soy Protein Isolate Hydrolysates with Cyanidin-3-O-Glucoside and Its Effect on the In Vitro Antioxidant Capacity of the Complexes under Neutral Condition

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1721
Author(s):  
Yaru Wu ◽  
Zhucheng Yin ◽  
Xuejiao Qie ◽  
Yao Chen ◽  
Maomao Zeng ◽  
...  
Keyword(s):  
Antioxidant Capacity ◽  
Soy Protein ◽  
Average Particle Size ◽  
Soy Protein Isolate ◽  
Surface Hydrophobicity ◽  
Protein Isolate ◽  
Antagonistic Effect ◽  
Masking Effect ◽  
Average Particle

The interaction of soy protein isolate (SPI) and its hydrolysates (SPIHs) with cyanidin-3-O-glucoside (C3G) at pH 7.0 were investigated to clarify the changes in the antioxidant capacity of their complexes. The results of intrinsic fluorescence revealed that C3G binds to SPI/SPIHs mainly through hydrophobic interaction, and the binding affinity of SPI was stronger than that of SPIHs. Circular dichroism and Fourier-transform infrared spectroscopy analyses revealed that the interaction with C3G did not significantly change the secondary structures of SPI/SPIHs, while the surface hydrophobicity and average particle size of proteins decreased. Furthermore, the SPI/SPIHs-C3G interaction induced an antagonistic effect on the antioxidant capacity (ABTS and DPPH) of the complex system, with the masking effect on the ABTS scavenging capacity of the SPIHs-C3G complexes being lower than that of the SPI-C3G complexes. This study contributes to the design and development of functional beverages that are rich in hydrolysates and anthocyanins.

scholarly journals Isolation, Characterization, and Identification of Biological Control Agent for Potato Soft Rot in Bangladesh

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
M. M. Rahman ◽  
M. E. Ali ◽  
A. A. Khan ◽  
A. M. Akanda ◽  
Md. Kamal Uddin ◽  
...  
Keyword(s):  
Biological Control ◽  
Biological Control Agent ◽  
Erwinia Carotovora ◽  
Soft Rot ◽  
Control Agent ◽  
Antagonistic Activity ◽  
Antagonistic Effect ◽  
Antagonistic Bacteria ◽  
And Storage

A total of 91 isolates of probable antagonistic bacteria of potato soft rot bacteriumErwinia carotovorasubsp.carotovora(Ecc) were extracted from rhizospheres and endophytes of various crop plants, different soil varieties, and atmospheres in the potato farming areas of Bangladesh. Antibacterial activity of the isolated probable antagonistic bacteria was testedin vitroagainst the previously identified most common and most virulent soft rot causing bacterial strain Ecc P-138. Only two isolates E-45 and E-65 significantly inhibited thein vitrogrowth of Ecc P-138. Physiological, biochemical, and carbon source utilization tests identified isolate E-65 as a member of the genusBacillusand the isolate E-45 asLactobacillussp. The stronger antagonistic activity against Ecc P-138 was found in E-65in vitroscreening and storage potatoes. E-65 reduced the soft rot infection to 22-week storage potatoes of different varieties by 32.5–62.5% in model experiment, demonstrating its strong potential to be used as an effective biological control agent for the major pectolytic bacteria Ecc. The highest (62.5%) antagonistic effect of E-65 was observed in the Granola and the lowest (32.7%) of that was found in the Cardinal varieties of the Bangladeshi potatoes. The findings suggest that isolate E-65 could be exploited as a biocontrol agent for potato tubers.

scholarly journals Antifungal activity of several isolates of Trichoderma against Cladosporium and Botrytis

2018 ◽  
Vol 8 (1) ◽  
pp. 88-91 ◽  
Author(s):  
M. Skaptsov ◽  
S. Smirnov ◽  
M. Kutsev ◽  
O. Uvarova ◽  
T. Sinitsyna ◽  
...  
Keyword(s):  
Antifungal Activity ◽  
Trichoderma Harzianum ◽  
Its Region ◽  
Botanical Garden ◽  
Antagonistic Activity ◽  
Antagonistic Effect ◽  
Soil Samples ◽  
Morphological Observation ◽  
The South

<p><em>Trichoderma</em> isolates (SSBGT07, SSBGT08, SSBGT09, SSBGT10) were isolated from the soil samples of the South-Siberian Botanical Garden and identified using morphological observation and ITS region analysis as <em>Trichoderma harzianum</em>, <em>T. asperellum, T. ghanense</em>, and <em>T. longibranchiatum</em>. Antagonistic activity against <em>Cladosporium </em>sp. and<em> Botrytis </em>sp. was evaluated <em>in vitro</em>. All isolates showed antagonistic effect by competition against <em>Cladosporium </em>sp. <em>T. asperellum </em>and <em>T. longibranchiatum</em> showed antagonism against <em>Botrytis </em>sp. All isolates showed hyper sporulation on the sclerotia of <em>Botrytis</em> sp. (except the <em>T. ghanense</em>) and colonies of the <em>Cladosporium</em> sp. Our study provides new isolates that affect the <em>Cladosporium </em>sp. and<em> Botrytis </em>sp.</p>

scholarly journals Antagonistic effectiveness of some bacteria against Fusarium graminearum causing crown rot disease on wheat (Triticum aestivum)

2021 ◽  
Vol 13 (1) ◽  
pp. 69-80
Author(s):  
Majida Hadi Mahdi Alsaady ◽  
Hussein Ali Salim ◽  
Rakib A. Al-ani ◽  
Hadi M. Aboud ◽  
Jamal Talib M Al Roubaie
Keyword(s):  
Fusarium Graminearum ◽  
Culture Method ◽  
Dry Weight ◽  
Antagonistic Effect ◽  
Crown Rot ◽  
Control Treatment ◽  
Enzyme Analysis ◽  
Dual Culture ◽  
Rot Disease

In this study, the antagonistic effect of five bacteria genera namely Bacillus, Pseudomonas, Azotobacter, Azospirillum, and Streptomyces isolated from rhizosphere of wheat were evaluated against Fusarium graminearum as potential biocontrol agents in vitro. F. graminearum was molecularly diagnosed using the Polymerase chain reaction (PCR) technique. Each bacteria were tested for the production of catalase enzyme, oxidase enzyme, analysis of starch, analyze of gelatin, and the motility, where Azotobacter, Azospirillum, and Bacillus subtilis were positive for all tested. Fungal inhibition tests were performed by using the dual culture method and agar well diffusion technique. Among them, Streptomyces and Azospirillum exhibited potent inhibition to the growth of F. graminearum (72.14% and 66.42%) respectively, followed by B.pumillus, P.fluorescens, B. subtilis and Azotobacter ( 58.28%, 43.23%, 39.71% and 35.71%) respectively as compared with the control treatment (0.0%).The dry weight of the fungus biomass was decreased with bacteria P. fluorescens, Streptomyces sp, Azotobacter sp, Azospirillum sp, B. subtilis, and B. pumillus which reached (0.114, 0.103, 0.147, 0.101, 0.143, and 0.107 g) respectively compared to the control treatment that was 0. 665 g.

scholarly journals Streptococcus pluranimalium 2N12 Exerts an Antagonistic Effect Against the Swine Pathogen Actinobacillus pleuropneumoniae by Producing Hydrogen Peroxide

2021 ◽  
Vol 8 ◽  
Author(s):  
Katy Vaillancourt ◽  
Michel Frenette ◽  
Marcelo Gottschalk ◽  
Daniel Grenier
Keyword(s):  
Hydrogen Peroxide ◽  
Culture Supernatant ◽  
Actinobacillus Pleuropneumoniae ◽  
Antagonistic Effect ◽  
Economic Losses ◽  
Protective Mechanism ◽  
Upper Respiratory Tract ◽  
Lactate Oxidase ◽  
Swine Industry

Actinobacillus pleuropneumoniae is the causal agent of porcine pleuropneumonia, a highly contagious and often deadly respiratory disease that causes major economic losses in the swine industry worldwide. The aim of the present study was to investigate the hydrogen peroxide (H2O2)-dependent antagonistic activity of Streptococcus pluranimalium 2N12 (pig nasal isolate) against A. pleuropneumoniae. A fluorimetric assay showed that S. pluranimalium produces H2O2 dose- and time-dependently. The production of H2O2 increased in the presence of exogenous lactate, suggesting the involvement of lactate oxidase. All 20 strains of A. pleuropneumoniae tested, belonging to 18 different serovars, were susceptible to H2O2, with minimal inhibitory concentrations and minimal bactericidal concentrations ranging from 0.57 to 2.3 mM. H2O2, as well as a culture supernatant of S. pluranimalium, killed planktonic cells of A. pleuropneumoniae. Treating the culture supernatant with catalase abolished its bactericidal property. H2O2 was also active against a pre-formed biofilm-like structure of A. pleuropneumoniae albeit to a lesser extent. A checkerboard assay was used to show that there were antibacterial synergistic interactions between H2O2 and conventional antibiotics, more particularly ceftiofur. Based on our results and within the limitations of this in vitro study, the production of H2O2 by S. pluranimalium could be regarded as a potential protective mechanism of the upper respiratory tract against H2O2-sensitive pathogens such as A. pleuropneumoniae.

scholarly journals Potential of Trichosporon asahii against Alternaria sp. and mechanisms of actions

2020 ◽  
Vol 46 (1) ◽  
pp. 20-25
Author(s):  
Ariane Silva Bosqueiro ◽  
Rodolfo Bizarria Júnior ◽  
Márcia Maria Rosa-Magri
Keyword(s):  
Antagonistic Activity ◽  
Mechanisms Of Action ◽  
Antagonistic Effect ◽  
Production Chain ◽  
Trichosporon Asahii ◽  
Modern Agriculture ◽  
Killer Toxins ◽  
Alternaria Sp ◽  
Mycelial Development

ABSTRACT Alternaria sp. is a fungus that causes rot in several crops, causing damage to the agricultural production chain. Biological control agents constitute an alternative to reduce the use of pesticides in the crops, a social demand for modern agriculture. The aim of the present study is to demonstrate the antagonistic effect of the yeast Trichosporon asahii (3S44) on the mycelial development of Alternaria sp. and some in vitro mechanisms of action. Trichosporon asahii showed antagonistic activity towards Alternaria sp., presenting mycelial inhibition (57.47%). The assays indicated production of volatile organic compounds (VOCs), competition for nutrients, biofilm formation, production of killer toxins and β-1,3-glucanase as mechanisms of action of T. asahii. Collectively, our results showed the potential of T. asahii to control the mycelial development of Alternaria sp. and some mechanisms of action of this yeast for future biotechnological studies.

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