scholarly journals The Effect of Surfactants of Microbial Origin on Phytopathogenic Microorganisms

2021 ◽  
Vol 83 (6) ◽  
pp. 75-94
Author(s):  
T.P. Pirog ◽  
◽  
D.V. Piatetska ◽  
H.А. Yarova ◽  
G.O. Iutynska ◽  
...  

Biodegradable non-toxic surfactants of microbial origin are multifunctional preparations, which due to antimicrobial activity are promising for use in crop production to control phytopathogenic microorganisms. Studies on the prospects of using microbial surfactants to control the number of phytopathogenic microorganisms are conducted in three directions: laboratory studies of antimicrobial activity of surfactants in vitro, determination of the effect of surfactants on phytopathogens in vegetative experiments in the process of plants growing in a laboratory or greenhouse, post-harvest treatment of fruits and vegetables with solutions of microbial surfactants to extend their shelf life. The review presents literature data on antimicrobial activity of surfactants against phytopathogenic bacteria and fungi in vitro. Antimicrobial activity of surfactants is evaluated by three main parameters: minimum inhibitory concentration, zones of growth retardation of test cultures on agar media and inhibition of growth of test cultures on agar or liquid media. The vast majority of available publications relate to the antifungal activity of surfactant lipopeptides and rhamnolipids, while data on the effect of these microbial surfactants on phytopathogenic bacteria (representatives of the genera Ralstonia, Xanthomonas, Pseudomonas, Agrobacterium, Pectobacterium) are few. The researchers determined the antimicrobial activity of either total lipopeptides extracted with organic solvents from the culture broth supernatant, or individual lipopeptides (iturin, surfactin, fengycin, etc.) isolated from a complex of surfactants, or culture broth supernatant. Lipopeptides synthesized by members of the genus Bacillus exhibit antimicrobial activity on phytopathogenic fungi of the genera Alternaria, Verticillium, Aspergillus, Aureobasidium, Botrytis, Rhizoctonia, Fusarium, Penicillium, Phytophora, Sclerotinia, Curvularia, Colletotrichum, etc. in sufficiently high concentrations. Thus, the minimum inhibitory concentrations of lipopeptides against phytopathogenic fungi are orders of magnitude higher (in average 0.04–8.0 mg/mL, or 40–8000 μg/mL) than against phytopathogenic bacteria (3–75 μg/mL). However, the antifungal activity of lipopeptidecontaining supernatants is not inferior by the efficiency to the activity of lipopeptides isolated from them, and therefore, to control the number of phytopathogenic fungi in crop production, the use of lipopeptidecontaining supernatants is more appropriate. Rhamnolipids synthesized by bacteria of the genus Pseudomonas are more effective antimicrobial agents comparing to lipopeptides: the minimum inhibitory concentrations of rhamnolipids against phytopathogenic fungi are 4–276 μg/mL, which is an order of magnitude lower than lipopeptides. In contrast to the data on the antifungal activity of rhamnolipids against phytopathogens, there are only a few reports in the literature on the effect of these surfactants on phytopathogenic bacteria, whilst the minimal inhibitory concentrations are quite high (up to 5000 μg/mL). The advantage of rhamnolipids as antimicrobial agents compared to lipopeptides is the high level of synthesis on cheap and available in large quantities industrial waste. Currently in the literature there is little information about the effect of surface-active sophorolipids of microbial origin on phytopathogenic fungi, and all these works are mainly about the antifungal activity of sophorolipids. We note that in contrast to surfactant lipopeptides and rhamnolipids, the effective concentration of most sophorolipids, which provides the highest antimicrobial activity against phytopathogens, is higher and reaches 10,000 μg/mL.

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4383
Author(s):  
Barbara Lapinska ◽  
Aleksandra Szram ◽  
Beata Zarzycka ◽  
Janina Grzegorczyk ◽  
Louis Hardan ◽  
...  

Modifying the composition of dental restorative materials with antimicrobial agents might induce their antibacterial potential against cariogenic bacteria, e.g., S.mutans and L.acidophilus, as well as antifungal effect on C.albicans that are major oral pathogens. Essential oils (EOs) are widely known for antimicrobial activity and are successfully used in dental industry. The study aimed at evaluating antibacterial and antifungal activity of EOs and composite resin material (CR) modified with EO against oral pathogens. Ten EOs (i.e., anise, cinnamon, citronella, clove, geranium, lavender, limette, mint, rosemary thyme) were tested using agar diffusion method. Cinnamon and thyme EOs showed significantly highest antibacterial activity against S.mutans and L.acidophilus among all tested EOs. Anise and limette EOs showed no antibacterial activity against S.mutans. All tested EOs exhibited antifungal activity against C.albicans, whereas cinnamon EO showed significantly highest and limette EO significantly lowest activity. Next, 1, 2 or 5 µL of cinnamon EO was introduced into 2 g of CR and microbiologically tested. The modified CR showed higher antimicrobial activity in comparison to unmodified one. CR containing 2 µL of EO showed the best antimicrobial properties against S.mutans and C.albicans, while CR modified with 1 µL of EO showed the best antimicrobial properties against L.acidophilus.


2021 ◽  
Vol 10 (1) ◽  
pp. 76-82
Author(s):  
Prabhulingayya S Bhixavatimath ◽  
Yasmeen Maniyar ◽  
Akram Naikawadi ◽  
Vijayakumar D

Introduction: In recent times, most of the currently available antimicrobial agents have developed resistance. Extensive pharmacological activities including bactericidal and bacteriostatic nature of flavonoids, made them as priority agents in this aspect of research study. Synthetic flavonoids such as hydroxy thiophen derivatives were considered to evaluate for antimicrobial activity in this study.   Objective: The present study involves the analysis for antimicrobial activity of thiophen substituted synthetic flavonoids. Methods: Claisen-Schmidt method of condensation fallowed by oxidative cyclization reactions from substituted hydroxyacetophenone with aromatic aldehydes were used to synthesize the various analogues of flavonoid compounds. Then these compounds after their FTIR, 1H NMR, MS spectral characterization and elemental analysis, were screened for in vitro antibacterial and antifungal activity by using disc diffusion method followed by determining their respective zone of inhibitions. Results: All the synthesized test flavonoid compounds exhibited the good antibacterial and antifungal  spectrum activity over B. subtilis, S. aureus, E. coli and P. aeurugenosa bacteria and Candida albicans and Aspergillus niger fungal microbes. However compounds such as F1, F2 and F4 showed moderately significant antibacterial activity against P. aerugenosa organism than the other test compounds and the same F1 and F2 test compounds exhibited significant antifungal activity at100µg concentration. Conclusion:  The present study demonstrated that the novel thiophen substituted flavonoids (F1, F2, F3 and F4 ) found to have promising antimicrobial and antifungal activity which needs to be confirmed by in vivo studies.


2018 ◽  
Vol 16 (1) ◽  
pp. 3-10
Author(s):  
Aniket P. Sarkate ◽  
Kshipra S. Karnik ◽  
Pravin S. Wakte ◽  
Ajinkya P. Sarkate ◽  
Ashwini V. Izankar ◽  
...  

Background:A novel copper-catalyzed synthesis of substituted-1,2,3-triazole derivatives has been developed and performed by Huisgen 1,3-dipolar cycloaddition reaction of azides with alkynes. The reaction is one-pot multicomponent.Objective:We state the advancement and execution of a methodology allowing for the synthesis of some new substituted 1,2,3-triazole analogues with antimicrobial activity.Methods:A series of triazole derivatives was synthesized by Huisgen 1,3-dipolar cycloaddition reaction of azides with alkynes. The structures of the synthesized compounds were elucidated and confirmed by 1H NMR, IR, MS and elemental analysis. All the synthesized compounds were tested for their antimicrobial activity against a series of strains of Bacillus subtilis, Staphylococcus aureus and Escherichia coli for antibacterial activity and against the strains of Candida albicans, Aspergillus flavus and Aspergillus nigar for antifungal activity, respectively.Results and Conclusion:From the antimicrobial data, it was observed that all the newly synthesized compounds showed good to moderate level of antibacterial and antifungal activity.


2019 ◽  
Vol 15 (1) ◽  
pp. 63-70
Author(s):  
Shiv Dev Singh ◽  
Arvind Kumar ◽  
Firoz Babar ◽  
Neetu Sachan ◽  
Arun Kumar Sharma

Background: Thienopyrimidines are the bioisoster of quinazoline and unlike quinazoline exist in three isomeric forms corresponding to the three possible types annulation of thiophene to the pyrimidine ring viz thieno[2,3-d] pyrimidine, thieno[3,2-d] pyrimidine and thieno[3,4-d]pyrimidine. Heterocyclic containing the thienopyrimidinone moiety exhibits various pronounced activities such as anti-hypertensive, analgesic and anti-inflammatory, antiviral, platelet aggregation inhibitory, antiprotozoal bronchodilatory, phosphodiesterase inhibitory, antihistaminic, antipsychotic and antimicrobial activity. Objective: Synthesis of novel 3(N,N-dialkylamino)alkyl/phenyl substituted thieno[2,3-d]pyrimidinones as H1-anti-histaminic and antimicrobial agents. Methods: A series of 3-[(N,N-dialkylamino)alkyl/phenyl]-2-(1H)thioxo-5,6,7,8-tetrahydrobenzo(b) thieno(2,3-d)pyrimidine-4(3H)-ones[4a-d], their oxo analogous [5a-d] and 3-[(N,N-dialkylamino)alkyl]- 2-chlorophenyl-5,6,7,8-tetrahydrobenzo(b)thieno(2,3-d)pyrimidine- 4 (3H)-ones[6a-d]derivative were synthesized from 2-amino-4,5,6,7-tetrahydrobenzo(b)thiophene-3-carboxylic acid by nucleophilic substitution of different N,N-dialkyl alkylene/phenylene diamines on activated 3-acylchloride moiety followed by cyclocondensation with carbon disulfide and ethanolic potassium hydroxide to get [4a-d] and in second reaction by condensation with 4-chlorobenzoyl chloride to get [6a-d] by single pot novel innovative route. The oxo analogous [5a-d] were prepared by treating derivatives [4a-d] with potassium permagnate in ethanolic KOH. The synthesized compound were evaluated for H1-antihistaminic and antimicrobial activities. Results: All synthesized compounds exhibited significant H1-antihistaminic activity by in vitro and in vivo screening methods and data were verified analytically and statistically. The compound 4a, 4b, 5a and 5b showed significant H1-antihistaminiic activity than the reference standard chlorpheniramine maleate. The compound 6d, 6c, 5c and 4c exhibited significant antimicrobial activity.


Molecules ◽  
2012 ◽  
Vol 17 (11) ◽  
pp. 13026-13035 ◽  
Author(s):  
Xin-Juan Yang ◽  
Fang Miao ◽  
Yao Yao ◽  
Fang-Jun Cao ◽  
Rui Yang ◽  
...  

Author(s):  
Aseel Alsarahni ◽  
Zuhair Muhi Eldeen ◽  
Elham Al-kaissi ◽  
Ibrahim Al- Adham ◽  
Najah Al-muhtaseb

<p><strong>Objective: </strong>To design and synthesize amino acetylenic and thiocarbonate of 2-mercapto-1,3-benthiazoles as potential antimicrobial agents.</p><p><strong>Methods: </strong>A new series of 2-{[4-(t-amino-1-yl) but-2-yn-1-yl] sulfanyl}-1,3-benzothiazole derivatives (AZ1-AZ6), and S-1,3-benzothiazol-2-yl-O-alkyl carbonothioate derivatives were synthesised, with the aim that the target compounds show new and potential antimicrobial activity. The elemental analysis was indicated by the EuroEA elemental analyzer, and biological characterization was via IR, <sup>1</sup>H-NMR, [13]C-NMR, DSC were determined with the aid of Bruker FT-IR and Varian 300 MHz spectrometer using DMSO-d<sub>6</sub> as a solvent.<em> </em><em>In vitro </em>antimicrobial activity, evaluation was done for the synthesised compounds, by agar diffusion method and broth dilution test. The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) were determined. <em></em></p><p><strong>Results: </strong>The IR, <sup>1</sup>H-NMR, <sup>13</sup>C-NMR, DSC and elemental analysis were consistent with the assigned structures. Compound of 2-{[4-(4-methylpiperazin-1-yl)but-2-yn-1-yl] sulfanyl}-1,3-benzothiazole (AZ1), 2-{[4-(2-methylpiperidin-1-yl)but-2-yn-1-yl]sulfanyl}-1,3-benzothiazole (AZ2), 2-{[4-(piperidin-1-yl) but-2-yn-1-yl]sulfanyl}-1, 3-benzothiazole (AZ6), S-1,3-benzothiazol-2-yl-O-ethyl carbonothioate (AZ7), and S-1,3-benzothiazol-2-yl-O-(2-methylpropyl) carbonothioate (AZ9) showed the highest antimicrobial activity against <em>Pseudomonas aeruginosa </em>(<em>P. aeruginosa</em>), AZ-9 demonstrated the highest antifungal activity against <em>Candida albicans </em>(<em>C. albicans</em>), with MIC of 31.25 µg/ml.</p><p><strong>Conclusion: </strong>These promising results promoted our interest to investigate other structural analogues for their antimicrobial activity further.</p>


2021 ◽  
Vol 11 (6) ◽  
pp. 888-903
Author(s):  
Hanan Alghamdi ◽  
Syed Nazreen ◽  
Ahmed A. Elhenawy ◽  
Mohamed Abdelbaset

The antimicrobial resistance is a global human threat which has led to the withdrawal of antibiotics from the market. Therefore, it is a need to develop new and effective antimicrobial agents to overcome this problem. In this paper, new Dioxovanadium(V) complexes (1–8) with ligands viz. (2-(5-phenyl-1,3,4-oxadiazole-2-yl)phenol; L1) and 2,5-bis(2-hydroxyphenyl)-1,3,4-oxadiazole (L2) were synthesized and assessed for antimicrobial-activity. Both a bidentate and tetradentate oxadiazole ligands coordinate with vanadium ions through the nitrogen and oxygen atoms giving octahedral geometries. Thermal analysis and IR data confirmed the presence of hydrated water in the metal-complexes. The investigated compounds were assessed for antimicrobial viz four strains of bacterial and one a fungal strain. The antibacterial data showed that, the complexes (1–8) are lower potency against bacterial strain than the free ligands except (5) and (7) complexes. These complexness showed the highest antibacterial potency via the Staphylococcus aureus. All investigated compounds were inactive against C. albicans except complexes 2 and 5 which showed high activity. The performance of DFT was conducted to examine an interaction mode of the target compounds with biological system. The QSPR was calculated as: optimization geometries, (FMOs), and chemical-reactivities for the synthesized compounds. The (MEPs) were figured to predict the interaction behavior of the ligand and its complexes against the receptor. The molecular docking was performed against DNA gyrase to study the interaction mode with biological system.


INDIAN DRUGS ◽  
2015 ◽  
Vol 52 (04) ◽  
pp. 37-41
Author(s):  
S. M Pawaskar ◽  
◽  
K. C. Sasangan

The present study was undertaken to evaluate in vitro antimicrobial activity of the successive leaf extracts of Cynodon dactylon in petroleum ether, ethyl acetate, acetone, ethanol, methanol and water, against various gram positive & gram negative bacterial strains using zone of inhibition. Both Agar well diffusion method & Agar disc diffusion method were used to evaluate the antibacterial efficacy. The microorganisms used in the test were – Escherichia coli, Proteus vulgaris, Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa, Shigella flexneri, Salmonella typhi, Salmonella paratyphi A, Salmonella paratyphi B, Bacillus subtilis, Streptococcus pyogenes, Vibrio cholerac and Enterobacter aerogenes. Two fungal strains - Candida albicans and Saccharomyces cerevisiae were also tested to evaluate the antifungal potential of the said plant extract. The reference antibiotics chloramphenicol & ampicillin (antibacterial); nystatin & clotrimazole and (antifungal) were also tested against these standard microorganisms used in the assay and the results were compared with that of the plant extracts.The results of the study revealed that all the seven successive extracts of the leaf powder of Cynodon dactylon ( L.) Pers. exhibited prominent antimicrobial and antifungal activity against all microorganisms used in the study. The nonpolar extracts i.e. petroleum ether, ethyl acetate and acetone showed the most significant antibacterial and antifungal activity against all tested organisms. The petroleum ether and ethyl acetate extracts showing maximum inhibition in the range of 8 mm - 15 mm. This was closely followed by, acetone extract, which showed the inhibition in the range of 9 mm - 13 mm.


Antibiotics ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 188 ◽  
Author(s):  
Alberto Antonelli ◽  
Luca Giovannini ◽  
Ilaria Baccani ◽  
Valentina Giuliani ◽  
Riccardo Pace ◽  
...  

The recent increase in infections mediated by drug-resistant bacterial and fungal pathogens underlines the urgent need for novel antimicrobial compounds. In this study, the antimicrobial activity (inhibitory and cidal) of HybenX®, a novel dessicating agent, in comparison with commonly used sodium hypochlorite and chlorhexidine, against a collection of bacterial and yeast strains representative of the most common human pathogenic species was evaluated. The minimal inhibitory, bactericidal, and fungicidal concentrations (MIC, MBC, and MFC, respectively) of the three different antimicrobial agents were evaluated by broth microdilution assays, followed by subculturing of suitable dilutions. HybenX® was active against 26 reference strains representative of staphylococci, enterococci, Enterobacterales, Gram-negative nonfermenters, and yeasts, although at higher concentrations than sodium hypochlorite and chlorhexidine. HybenX® MICs were 0.39% for bacteria (with MBCs ranging between 0.39% and 0.78%), and 0.1–0.78% for yeasts (with MFCs ranging between 0.78% and 1.6%). HybenX® exhibited potent inhibitory and cidal activity at low concentrations against several bacterial and yeast pathogens. These findings suggest that HybenX® could be of interest for the treatment of parodontal and endodontic infections and also for bacterial and fungal infections of other mucous membranes and skin as an alternative to sodium hypochlorite and chlorhexidine.


2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Gabrielle Sherella Dijksteel ◽  
Peter H. Nibbering ◽  
Magda M. W. Ulrich ◽  
Esther Middelkoop ◽  
Bouke K. H. L. Boekema

Abstract Background Accurate determination of the efficacy of antimicrobial agents requires neutralization of residual antimicrobial activity in the samples before microbiological assessment of the number of surviving bacteria. Sodium polyanethol sulfonate (SPS) is a known neutralizer for the antimicrobial activity of aminoglycosides and polymyxins. In this study, we evaluated the ability of SPS to neutralize residual antimicrobial activity of antimicrobial peptides [SAAP-148 and pexiganan; 1% (wt/v) in PBS], antibiotics [mupirocin (Bactroban) and fusidic acid (Fucidin) in ointments; 2% (wt/wt))] and disinfectants [2% (wt/wt) silver sulfadiazine cream (SSD) and 0.5% (v/v) chlorhexidine in 70% alcohol]. Methods Homogenates of human skin models that had been exposed to various antimicrobial agents for 1 h were pipetted on top of Methicillin-resistant Staphylococcus aureus (MRSA) on agar plates to determine whether the antimicrobial agents display residual activity. To determine the optimal concentration of SPS for neutralization, antimicrobial agents were mixed with PBS or increasing doses of SPS in PBS (0.05–1% wt/v) and then 105 colony forming units (CFU)/mL MRSA were added. After 30 min incubation, the number of viable bacteria was assessed. Next, the in vitro efficacy of SAAP-148 against various gram-positive and gram-negative bacteria was determined using PBS or 0.05% (wt/v) SPS immediately after 30 min incubation of the mixture. Additionally, ex vivo excision wound models were inoculated with 105 CFU MRSA for 1 h and exposed to SAAP-148, pexiganan, chlorhexidine or PBS for 1 h. Subsequently, samples were homogenized in PBS or 0.05% (wt/v) SPS and the number of viable bacteria was assessed. Results All tested antimicrobials displayed residual activity in tissue samples, resulting in a lower recovery of surviving bacteria on agar. SPS concentrations at ≥0.05% (wt/v) were able to neutralize the antimicrobial activity of SAAP-148, pexiganan and chlorhexidine, but not of SSD, Bactroban and Fucidin. Finally, SPS-neutralization in in vitro and ex vivo efficacy tests of SAAP-148, pexiganan and chlorhexidine against gram-positive and gram-negative bacteria resulted in significantly higher numbers of CFU compared to control samples without SPS-neutralization. Conclusions SPS was successfully used to neutralize residual activity of SAAP-148, pexiganan and chlorhexidine and this prevented an overestimation of their efficacy.


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