scholarly journals Antifungal Activity of Propyl Disulfide from Neem (Azadirachta indica) in Vapor and Agar Diffusion Assays against Anthracnose Pathogens (Colletotrichum gloeosporioides and Colletotrichum acutatum) in Mango Fruit

2021 ◽  
Vol 9 (4) ◽  
pp. 839
Author(s):  
Muhammad Rafiullah Khan ◽  
Vanee Chonhenchob ◽  
Chongxing Huang ◽  
Panitee Suwanamornlert

Microorganisms causing anthracnose diseases have a medium to a high level of resistance to the existing fungicides. This study aimed to investigate neem plant extract (propyl disulfide, PD) as an alternative to the current fungicides against mango’s anthracnose. Microorganisms were isolated from decayed mango and identified as Colletotrichum gloeosporioides and Colletotrichum acutatum. Next, a pathogenicity test was conducted and after fulfilling Koch’s postulates, fungi were reisolated from these symptomatic fruits and we thus obtained pure cultures. Then, different concentrations of PD were used against these fungi in vapor and agar diffusion assays. Ethanol and distilled water were served as control treatments. PD significantly (p ≤ 0.05) inhibited more of the mycelial growth of these fungi than both controls. The antifungal activity of PD increased with increasing concentrations. The vapor diffusion assay was more effective in inhibiting the mycelial growth of these fungi than the agar diffusion assay. A good fit (R2, 0.950) of the experimental data in the Gompertz growth model and a significant difference in the model parameters, i.e., lag phase (λ), stationary phase (A) and mycelial growth rate, further showed the antifungal efficacy of PD. Therefore, PD could be the best antimicrobial compound against a wide range of microorganisms.

2021 ◽  
Vol 3 (1) ◽  
pp. 27
Author(s):  
Cláudia Ferreira ◽  
Rui Oliveira

Several phytopathogenic fungi greatly affect the production of important crops across the globe, as they lead to huge losses. To control diseases caused by fungal phytopathogens, a wide range of synthetic fungicides are applied in the fields. However, these agrochemicals are harmful for ecosystems (aerial, aquatic and terrestrial), non-target organisms and humans. In addition, since these antifungals have one specific cellular target, fungi can acquire resistance to them via the accumulation of mutations. Plant extracts provide natural alternatives to the use of synthetic fungicides in agriculture. Several plants are rich in secondary metabolites, including alkaloids, coumarins, flavonoids, terpenoids and saponins, which confer antifungal activity. This sustainable option is biodegradable, environmentally friendly and proves to be safer, and it is less prone to development resistance since they often have several cellular targets. This study was conducted to investigate the antifungal activity of Urtica dioica extract against Colletotrichum acutatum, Colletotrichum gloeosporioides, Colletotrichum godetiae, Colletotrichum nymphaeae, Diplodia corticola and Phytophthora cinnamomi. Urtica dioica extract was prepared with 50% (v/v) ethanol, the solvent was evaporated at a low pressure, and the residue was dissolved in water. The extract was incorporated into PDA medium at different concentrations (100, 500, 1000 and 2000 µg/mL) and mycelial discs were placed in the center of each Petri dish. Growth was measured in terms of radial mycelial growth in the third, sixth and ninth days of incubation, at 25 °C and in the dark. Urtica dioica extract was able to inhibit the growth of all strains except C. nymphaeae. Growth inhibition was around 20% at 2000 µg/mL for the remaining Colletotrichum species. An inhibition of growth was also observed with D. corticola in a concentration-dependent manner, from 100 µg/mL to 2000 µg/mL and revealed statistically significant differences (p < 0.05) between these concentrations. Regarding the growth of P. cinnamomi, significant differences were observed between the 100 µg/mL and 2000 µg/mL extract (p < 0.0001 and p < 0.05 on day 3 and 6, respectively). The most pronounced mycelial growth reduction (39.9%) was observed on day 3, an effect that is significantly different from (24.9%; p < 0.05) the result observed on the sixth day of incubation. Overall, the results of this work suggest U. dioca as a potential, ecologically sustainable alternative to conventional fungicides to protect crops from damage caused by phytopathogenic fungi.


2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Luce Mattio ◽  
Giorgia Catinella ◽  
Marcello Iriti ◽  
Lisa Vallone

Stilbenoids (resveratrol and its derivatives) are secondary metabolites produced by plants as defence mechanism to microbial infection. These compounds are known for their anti-inflammatory action and health benefits in preventing a wide range of disorders (e.g. cancer and cardiovascular diseases). However, their antimicrobial properties are less investigated. A series of 8 stilbenoid compounds were synthesized and their antifungal activity against 19 wild strains of filamentous fungi and yeasts (isolated from the environment and food) was tested in vitro. Using an agar diffusion assay, compounds were tested at the concentration of 100 μg/ml on filamentous fungi and yeasts at 104 CFU/ml. The results showed that tested derivatives possess moderate antifungal activity: in particular, monomeric stilbenoids 3’-hydroxy-pterostilbene and piceatannol, and dimeric stilbenoids (±)-trans-δ-viniferin and pallidol were active against mycotoxigenic fungi.


2018 ◽  
Vol 13 (3) ◽  
pp. 1934578X1801300 ◽  
Author(s):  
Andrea Labruzzo ◽  
Charles L. Cantrell ◽  
Alessandra Carrubba ◽  
Abbas Ali ◽  
David E. Wedge ◽  
...  

A systematic bioassay-guided fractionation of methylene chloride extracts of the aerial part of Artemisia arborescens was performed in order to identify its phytotoxic compounds Two lignans were isolated, sesamin and ashantin, that inhibited growth of Agrostis stolonifera (bentgrass), a monocot, and Lactuca sativa (lettuce), a dicot, at 1 mg mL–1. In a dose-response screening of these lignans for growth inhibition against Lemna paucicostata (duckweed), ashantin was the most active with an IC50 of ca. 224 μM. The mode of action of these compounds is still unknown. In mosquito larvicidal bioassays the pure compounds sesamin and ashantin did not cause mortality at the highest dose of 125 mg/L against 1-d-old Aedes aegypti larvae. In bioautography bioassays for antifungal activity using Botrytis cinerea, Fusarium oxysporum, Colletotrichum fragariae, Colletotrichum acutatum, and Colletotrichum gloeosporioides, ashantin and sesamin were inactive at 5 μg and were therefore not subjected to additional screening in secondary antifungal assays.


Toxins ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 513
Author(s):  
Wassim Habib ◽  
Mario Masiello ◽  
Romy El Ghorayeb ◽  
Elvis Gerges ◽  
Antonia Susca ◽  
...  

The tomato is one of the most consumed agri-food products in Lebanon. Several fungal pathogens, including Alternaria species, can infect tomato plants during the whole growing cycle. Alternaria infections cause severe production and economic losses in field and during storage. In addition, Alternaria species represent a serious toxicological risk since they are able to produce a wide range of mycotoxins, associated with different toxic activities on human and animal health. Several Alternaria species were detected on tomatoes, among which the most important are A. solani, A. alternata, and A. arborescens. A set of 49 Alternaria strains isolated from leaves and stems of diseased tomato plants were characterised by using a polyphasic approach. All strains were included in the recently defined phylogenetic Alternaria section and grouped in three well-separated sub-clades, namely A. alternata (24 out of 49), A. arborescens (12 out of 49), and A. mali morpho-species (12 out of 49). One strain showed high genetic similarity with an A.limoniasperae reference strain. Chemical analyses showed that most of the Alternaria strains, cultured on rice, were able to produce alternariol (AOH), alternariol methyl ether (AME), altenuene (ALT) and tenuazonic acid (TA), with values up to 5634, 16,006, 5156, and 4507 mg kg−1, respectively. In addition, 66% of the strains were able to co-produce simultaneously the four mycotoxins investigated. The pathogenicity test carried out on 10 Alternaria strains, representative of phylogenetic sub-clades, revealed that they were all pathogenic on tomato fruits. No significant difference among strains was observed, although A. alternata and A. arborescens strains were slightly more aggressive than A. mali morpho-species strains. This paper reports new insights on mycotoxin profiles, genetic variability, and pathogenicity of Alternaria species on tomatoes.


2011 ◽  
Vol 13 (4) ◽  
pp. 408-412 ◽  
Author(s):  
E.S. Naruzawa ◽  
M.F.S. Papa

This study aimed to determine the antifungal activity of leaf aqueous and hydroethanolic extracts of 10 plants from the Brazilian Cerrado on Colletotrichum gloeosporioides and Corynespora cassiicola. Antifungal activity was measured through the incorporation of each extract in a culture media or spore suspension, at 50% concentration relative to the volume, determining respectively the mycelial growth and the spore germination. Then, the percentages of mycelial growth inhibition and spore germination inhibition were obtained based on the comparison with the control. The extracts had a variable action on the phytopathogens, from mycelial growth stimulation for Aristolochia esperanzae and Byrsonima verbascifolia extracts to complete inhibition of mycelial growth and spore germination for Myracrodruon urundeuva and Lafoensia pacari extracts. M. urundeuva, L. pacari and Caryocar brasiliense leaf extracts had antifungal activity against Colletotrichum gloeosporioides and Corynespora cassiicola; the hydroethanolic extracts presented more antifungal activity than the aqueous extracts, and spore germination of both phytopathogens was more affected than their mycelial growth.


Pathogens ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 209
Author(s):  
Vantha Choub ◽  
Chaw Ei Htwe Maung ◽  
Sang-Jae Won ◽  
Jae-Hyun Moon ◽  
Kil Yong Kim ◽  
...  

The aim of this study was to investigate the antifungal activity of a cyclic tetrapeptide from Bacillus velezensis CE 100 against anthracnose-causing fungal pathogen Colletotrichum gloeosporioides. Antifungal compound produced by B. velezensis CE 100 was isolated and purified from ethyl acetate extract of B. velezensis CE 100 culture broth using octadecylsilane column chromatography. The purified compound was identified as cyclo-(prolyl-valyl-alanyl-isoleucyl) based on mass spectrometer and nuclear magnetic resonance analyses. This is the first report of the isolation of a cyclic tetrapeptide from B. velezensis CE 100 culture filtrate. Cyclic tetrapeptide displayed strong antifungal activity at concentration of 1000 µg/mL against C. gloeosporioides mycelial growth and spore germination. Our results demonstrate that the antifungal cyclic tetrapeptide from B. velezensis CE 100 has potential in bioprotection against anthracnose disease of plants caused by C. gloeosporioides.


2020 ◽  
Vol 9 (4) ◽  
pp. e27942662
Author(s):  
Patrícia Capellato ◽  
Cláudia Eliana Bruno Marino ◽  
Gilbert Silva ◽  
Lucas Victor Benjamim Vasconcelos ◽  
Rodrigo Perito Cardoso ◽  
...  

During the last decades, researchers have been growing the interest in surface treatment with an antimicrobial agent. Silver nanoparticles (AgNPs) are widely used in biomedical fields due to their potent antimicrobial activity. So, in this study was investigated silver particles (isles) coated on titanium surface for dental and orthopedic application. Silver particles coating process on titanium surface were performed via sputtering that is a plasma-assisted deposition technique with and titanium without treatment was applied as comparing standard. Plasma treatment parameters were optimized so that the result was not a thin film of Ag but dispersed particles of Ag on the Ti-cp surface. The alloy surfaces were investigated using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). In order to investigate antibacterial potential Staphylococcus aureus and Escherichia coli have been used at Agar diffusion assay. The results were analyzed by analysis of variance (ANOVA) in order to verify significant difference antimicrobial activity between samples that have shown no difference between the surfaces studied treatments. For silver deposition scattered particles (isles) over titanium surface for a 10-minute treatment, EDS revealed by silver clusters that the particles were not properly scattered onto surface, hence, the low effectiveness in antibacterial activity.


Author(s):  
A. Muntala ◽  
P. M. Norshie ◽  
K. G. Santo ◽  
C. K. S. Saba

A survey was conducted in twenty-five cashew (Anacardium occidentale) orchards in five communities in the Dormaa-Central Municipality of Bono Region of Ghana to assess the incidence and severity of anthracnose, gummosis and die-back diseases on cashew. Cashew diseased samples of leaves, stem, inflorescences, twigs, flowers, nuts and apples showing symptoms (e. g. small, water-soaked, circular or irregular yellow, dark or brown spots or lesions on leaves, fruits and flowers, sunken surface, especially on the apples, blight, gum exudates) were collected for isolation of presumptive causative organism. The pathogen was isolated after disinfecting the excised diseased pieces in 70% ethanol, plated on potato dextrose agar (PDA) and incubated at 28 oC for 3 to 7 days. The identity of the putative pathogen was morphologically and culturally confirmed as belonging to Colletotrichum gloeosporioides species complex using standard mycological identification protocols. The pathogen had varied conidia sizes of between 9-15 up to 20 μm in length and diameter of 3-6 μm. The conidia were straight and cylindrically shaped with rounded or obtuse ends. The septate mycelium was whitish-grey, velvety and cotton-like in appearance from the top. The results confirmed the presence of the pathogen in the orchards with incidence ranging from 6.9% and 14.0% for gummosis and averaged 22.9% for anthracnose infected orchards. The result of the pathogenicity test confirmed the isolates to be pathogenic on inoculated cashew seedlings and were consistently re-isolated, thereby establishing the pathogen as the true causal agent of the said diseases in cashew trees and thus completed the Koch’s postulate.


2017 ◽  
Vol 9 (2) ◽  
pp. 71
Author(s):  
Nurhasanah Nurhasanah ◽  
Fauzia Andrini ◽  
Yulis Hamidy

Shallot (Allium ascalonicum L.) has been known as traditional medicine. Shallot which has same genus with garlic(Allium sativum L.) contains allicin that is also found in garlic and has been suspected has fungicidal activity toCandida albicans. It is supported by several researches. Therefore, shallot is suspected has antifungal activity too.The aim of this research was to know antifungal activity of shallot’s water extortion againsts Candida albicans invitro. This was a laboratory experimental research which used completely randomized design, with diffusion method.Shallot’s water extortion was devided into three concentrations, there were 50%, 100% and 200%. Ketoconazole 2%was positive control and aquadest was negative control. The result of this research based on analysis of varians(Anova), there was significant difference between several treatments and was confirmed with Duncan New MultipleRange Test (DNMRT) p<0,05, there was significant difference between 100% shallot’s water extortion with othertreatments, but there was no significant difference between 50% shallot’s water extortion with 200% shallot’s. Theconclusion was shallot’s water extortion had antifungal activity againsts Candida albicans with the best concentration100%, but it was lower than ketoconazole 2%.


2017 ◽  
Vol 5 (2) ◽  
pp. 1
Author(s):  
Mulyati Mulyati ◽  
Suryati Suryati ◽  
Irfani Baga

The study aims to isolate, characterize, and examine probiotic bacteria's inhibitory ability against Vibrio harveyi bacteria, both in-vitro and in vivo. Methods used in the study consist of 1) An Isolation of Candidate Probiotic Bacteria, 2) An Antagonistic Test of Candidate Probiotic Bacteria in vitro, 3) An Identification of Bacteria, 4) A Pathogenicity Test of Candidate Probiotic Bacteria, 5) An Antagonistic Test of Candidate Probiotic Bacteria against V. harveyi in vivo. According to the isolation of candidate probiotic bacteria, there are 18 isolated candidate probiotic. After being tested for its inhibitory ability in vitro, there are 8 isolates with zone of inhibition as follows: isolate MM 7 from intestine (22 mm), isolate MM 6 from intestine (12 mm), isolate MM 10 from sea water (10 mm), isolate MM 5 from intestine (9 mm), isolate MM 4 from intestine (8 mm), isolate MM 3 from intestine (7 mm), isolate MM 2.2 from intestine (7 mm), isolate MM 2.1 from intestine (7 mm). Eight genera of the candidate probiotic bacteria is derived from Portunid crab, they are Staphylococcus, Streptococcus, bacillus, vibrio, Alcaligenes, Lactobacillus, micrococcus. Before proceeding the V. harveyi bacterial challenge test in vivo, three potential isolates consisting of MM6, MM7 and MM10 as the probiotic bacteria are pathogenicity-tested against V. harveyi. The survival rate of Portunid crab on pathogenicity test using MM6, MM7 and MM10 generates 91.11-100%, while the control generates 100% survival rate. Variance analysis result through post-hoc Tukey's Honest Significant Difference (HSD) test at 95% confidence interval indicates that isolate MM7 and MM10 are significantly able to increase hatchling Portunid crab's survival rate.


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