scholarly journals In vitro potential of Paenibacillus alvei DZ-3 as a biocontrol agent against several phytopathogenic fungi

Biologija ◽  
2018 ◽  
Vol 64 (1) ◽  
Author(s):  
Natalija Atanasova-Pancevska ◽  
Dzoko Kungulovski

Fungal phytopathogens cause significant losses in many economically important crops and vegetables. One way to control these devastating pathogens is using higher doses of fungicides that not only increase the cost of production but also cause significant damage to the environment. Consequently, there is an increasing demand from consumers and officials to reduce the use of chemical pesticides. In this context, biological control through the use of natural antagonistic microorganisms has emerged as a promising alternative. The goal of this paper is to evaluate environmentally-friendly treatment for in vitro control of some fungal phytopathogens. In the present study, the bacterial strain DZ-3, which shows strong antifungal activity, was isolated from the samples of rotten apple compost from the composting plant in Resen, Macedonia, and identified as Paenibacillus alvei according to morphological and taxonomic characteristics and 16S rRNA gene sequence analysis. As test microorganisms, we used Botrytis cinerea FNSFCC 23, Fusarium oxysporum FNS- FCC 103, Plasmopara viticola FNS- FCC 65, Alternaria alternata FNS- FCC 624, but also Aspergilus ochraceus FNS- FCC 46, Aspergilus niger FNS- FCC 142, and Penicillium commune FNS- FCC 864. The effect of Paenibacillus alvei DZ-3 on growth of the tested fungi was evaluated by the dual culture technique and disc diffusion method. Clear inhibition zones were observed in all test microorganisms. The above-described results indicate that Paenibacillus alvei DZ-3 may have the potential as a biocontrol agent to control various phytopathogenic fungi.

Agronomy ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 891
Author(s):  
Mila Santos ◽  
Fernando Diánez ◽  
Alejandro Moreno-Gavíra ◽  
Brenda Sánchez-Montesinos ◽  
Francisco J. Gea

A study was conducted to explore the efficacy of potential biocontrol agent Cladobotryum mycophilum against different phytopathogenic fungi. The growth rates of 24 isolates of C. mycophilum were determined, and their antagonistic activity was analysed in vitro and in vivo against Botrytis cinerea, Fusarium oxysporum f. sp. radicis-lycopersici, Fusarium oxysporum f.sp. cucumerinum, Fusarium solani, Phytophthora parasitica, Phytophthora capsici, Pythium aphanidermatum and Mycosphaerella melonis. Most isolates grow rapidly, reaching the opposite end of the Petri dish within 72–96 h. Under dual-culture assays, C. mycophilum showed antagonistic activity in vitro against all phytopathogenic fungi tested, with mycelial growth inhibition ranging from 30 to 90% against all the different phytopathogens tested. Similarly, of all the selected isolates, CL60A, CL17A and CL18A significantly (p < 0.05) reduced the disease incidence and severity in the plant assays compared to the controls for the different pathosystems studied. Based on these results, we conclude that C. mycophilum can be considered as a potential biological control agent in agriculture. This is the first study of Cladobotryum mycophilum as a biological control agent for different diseases caused by highly relevant phytopathogens in horticulture.


2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Mohamed Taha Yassin ◽  
Ashraf Abdel-Fattah Mostafa ◽  
Abdulaziz Abdulrahman Al-Askar

Abstract Background High losses of sorghum crops due to fungal diseases, such as grain mold and stalk rot, are economically harmful and cause increased use of environmentally damaging chemical fungicides, which also are detrimental to human health. Hence, finding safe and effective ways to manage fungal diseases of sorghum is urgently needed. Results In the present study, the antagonistic activities of Trichoderma viride and T. harzianum against different pathogenic fungal strains were evaluated in vitro using a dual culture assay. Furthermore, the anti-mycotic activity of Trichoderma spp. culture filtrates was evaluated against different fungal strains using a food poisoning technique. Additionally, the antifungal activities of ethyl acetate extracts of T. viride and T. harzianum against different pathogens were evaluated using a disk diffusion method. As indicated by the dual culture assay, T. harzianum suppressed 66.8, 69.5, 68.7, 54.6, 84.12, and 71.39% of the mycelial growth of Curvularia lunata, Exserohilum rostratum, Fusarium chlamydosporum, F. incarnatum, F. proliferatum, and Macrophomina phaseolina, respectively. T. viride was more effective for controlling the growth of these pathogens, inhibiting 81.0, 89.0, 63.0, 70.7, 84.4, and 71.8% of mycelial growth, respectively. Both E. rostratum and M. phaseolina showed resistance to carbendazim fungicide at all tested concentrations, whereas the fungicidal concentrations of carbendazim against C. lunata, F. chlamydosporum, and F. incarnatum strains were 2.50, 1.50, and 2.00 ppm, respectively. Furthermore, F. proliferatum was sensitive to carbendazim fungicide at all tested concentrations. Antifungal assays of the ethyl acetate extracts of T. viride and T. harzianum indicated the potent activity of these extracts against fungal phytopathogens with different susceptibility patterns. F. chlamydosporum was the most sensitive to the extracts of T. viride and T. harzianum with minimum inhibitory concentrations of 0.5 and 1.0 mg/disk, respectively. Conclusion The potent suppression of sorghum phytopathogens by T. viride and T. harzianum makes them potential sources of safe and effective natural fungicides compared to carbendazim fungicide.


2020 ◽  
Vol 13 (2) ◽  
pp. 54-65 ◽  
Author(s):  
M.E.A. Bendaha ◽  
H.A. Belaouni

SummaryThis study aims to develop a biocontrol agent against Fusarium oxysporum f.sp. radicis-lycopersici (FORL) in tomato. For this, a set of 23 bacterial endophytic isolates has been screened for their ability to inhibit in vitro the growth of FORL using the dual plate assay. Three isolates with the most sound antagonistic activity to FORL have been qualitatively screened for siderophore production, phosphates solubilization and indolic acetic acid (IAA) synthesis as growth promotion traits. Antagonistic values of the three candidates against FORL were respectively: 51.51 % (EB4B), 51.18 % (EB22K) and 41.40 % (EB2A). Based on 16S rRNA gene sequence analysis, the isolates EB4B and EB22K were closely related to Enterobacter ludwigii EN-119, while the strain EB2A has been assigned to Leclercia adecarboxylata NBRC 102595. The promotion of tomato growth has been assessed in vitro using the strains EB2A, EB4B and EB22K in presence of the phytopathogen FORL. The treatments with the selected isolates increased significantly the root length and dry weight. Best results were observed in isolate EB4B in terms of growth promotion in the absence of FORL, improving 326.60 % of the root length and 142.70 % of plant dry weight if compared with untreated controls. In the presence of FORL, the strain EB4B improved both root length (180.81 %) and plant dry weight (202.15 %). These results encourage further characterization of the observed beneficial effect of Enterobacter sp. EB4B for a possible use as biofertilizer and biocontrol agent against FORL.


2020 ◽  
Vol 30 (1) ◽  
Author(s):  
Zahaed Evangelista-Martínez ◽  
Erika Anahí Contreras-Leal ◽  
Luis Fernando Corona-Pedraza ◽  
Élida Gastélum-Martínez

Abstract Background Fungi are one of the microorganisms that cause most damage to fruits worldwide, affecting their quality and consumption. Chemical controls with pesticides are used to diminish postharvest losses of fruits. However, biological control with microorganisms or natural compounds is an increasing alternative to protect fruits and vegetables. In this study, the antifungal effect of Streptomyces sp. CACIS-1.5CA on phytopathogenic fungi that cause postharvest tropical fruit rot was investigated. Main body Antagonistic activity was evaluated in vitro by the dual confrontation over fungal isolates obtained from grape, mango, tomato, habanero pepper, papaya, sweet orange, and banana. The results showed that antagonistic activity of the isolate CACIS-1.5CA was similar to the commercial strain Streptomyces lydicus WYEC 108 against the pathogenic fungi Colletotrichum sp., Alternaria sp., Aspergillus sp., Botrytis sp., Rhizoctonia sp., and Rhizopus sp. with percentages ranging from 30 to 63%. The bioactive extract obtained from CACIS-1.5 showed a strong inhibition of fungal spore germination, with percentages ranging from 92 to 100%. Morphological effects as irregular membrane border, deformation, shrinkage, and collapsed conidia were observed on the conidia. Molecularly, the biosynthetic clusters of genes for the polyketide synthase (PKS) type I, PKS type II, and NRPS were detected in the genome of Streptomyces sp. CACIS-1.5CA. Conclusions This study presented a novel Streptomyces strain as a natural alternative to the use of synthetic fungicides or other commercial products having antagonistic microorganisms that were used in the postharvest control of phytopathogenic fungi affecting fruits.


2017 ◽  
Vol 7 (1) ◽  
pp. 10
Author(s):  
Tatsuya Ohike ◽  
Minori Maeda ◽  
Tetsuya Matsukawa ◽  
Masahiro Okanami ◽  
Shin’ichiro Kajiyama ◽  
...  

Rhizoctonia solani is fungal plant pathogen that infects many different host plants. Recently, biological control agents that are friendly to the environment and ecosystems have attracted much attention as an alternative to the use of chemical fungicide which have been used worldwide to control soil borne pathogens including R. solani. In this study, 53 strains of actinomycetes isolated from environmental soils, and antifungal activities of them were assessed by the dual culture assay. Strain KT showed strong inhibitory activities against 8 phytopathogenic fungi. A great suppressive effect on R. solani growth was observed in the inoculation test of plants using cucumber and chin-geng-sai. In addition, infection of Bipolaris oryzae also could be suppressed in the detached leaf assay using oats. As a result of genetic analysis, it was shown that KT was a species closely related to Streptomyces lavenduligriseus NRRL B-3173T. However, as far as we know, there is no report for biological control agents using S. lavenduligriseus. This study suggests that the strain KT may useful as biological control agents to suppress various crop diseases.


2007 ◽  
Vol 53 (2) ◽  
pp. 207-212 ◽  
Author(s):  
Naveen Kumar Arora ◽  
Min Jeong Kim ◽  
Sun Chul Kang ◽  
Dinesh Kumar Maheshwari

A study was conducted to investigate the possibility of involvement of chitinase and β-1,3-glucanase of an antagonistic fluorescent Pseudomonas in growth suppression of phytopathogenic fungi, Phytophthora capsici and Rhizoctonia solani . Fluorescent Pseudomonas isolates GRC3 and GRC4 were screened for their antifungal potential against phytopathogenic fungi by using dual culture technique both on solid and liquid media. The percent inhibition was calculated. Various parameters were monitored for optimization of enzyme activities by fluorescent Pseudomonas GRC3. The involvement of chitinases, β-1,3-glucanases, and antifungal metabolites of nonenzymatic nature was correlated with the inhibition of P. capsici and R. solani. The results provide evidence for antibiosis as a mechanism for antagonism. The study also confirms that multiple mechanisms are involved in suppressing phytopathogens as evidenced by the involvement of chitinase and β-1,3-glucanase in inhibition of R. solani but not P. capsici by isolate GRC3.


2020 ◽  
Vol 14 (1) ◽  
pp. 70-77
Author(s):  
Ziyaul Haque ◽  
Mohammed S. Iqbal ◽  
Ausaf Ahmad ◽  
Mohd S. Khan ◽  
Jyoti Prakash

Objective: In the present investigation, Trichoderma spp., isolated from rhizospheric soil, has been identified by Internal Transcribed Spacer (ITS) region sequencing technique and its antagonistic activity was evaluated against A. niger. Methods: The sequencing analysis was done with its ITS1 region of the rRNA gene. Using the ITS1 amplified products for all isolated fungi, a bi-directional DNA sequencing was done with high quality bases (>98% - 100%). Antagonistic activity was done using dual culture technique. Results: All of the ITS1 nucleotide sequences obtained in this study matched 97% - 100% with the published sequence of Trichoderma spp. The results confirmed the strains as T. asperellum and T. viride with gene bank accession no. (ZTa); MK937669 and (ZTv); MK503705, respectively. When phylogenetic analysis was done for the isolates, the optimal tree with the sum of branch length = 0.69585023 and 0.10077756 for T. asperellum and T. viride, respectively, was observed. There were a total of 678 and 767 for T. asperellum and T. viride positions in the final dataset, respectively. Antagonistic activity was done for the isolated strains of Trichoderma spp. against A. niger, and it was found that T. asperellum showed maximum antagonistic activity (79.33±7.09%). Conclusion: The findings prolong the genome availability for relative investigations pointing out phenotypic variances to compare with Trichoderma genetic diversity. The present investigation delivered the Bases of future studies for better knowledge in understanding the complicated connections of Trichoderma spp. to be used as an effective biocontrol agent.


2021 ◽  
Vol 25 (2) ◽  
pp. 197
Author(s):  
Rochmalia Juniarti Putri ◽  
Retno Kawuri ◽  
Anak Agung Ketut Darmadi ◽  
Inna Narayani

Red chilli plant (Capsicum annum L.) is one of the most popular vegetable crops in Indonesian society. One of them the pathogens attacks is Colletotrichum acutatum, a fungus causing anthracnose on red chilli. This study aims to determine the existence of Streptomyces sp. bacteria in the rhizosphere of the red chilli plant; the ability of Streptomyces sp. in inhibiting C. acutatum; Minimum Inhibitory Concentration (MIC) of Streptomyces isolates extracts in inhibiting C. acutatum; The Streptomyces isolation was carried out by dilution method using selective meida, namely Yeast Malt Agar. The Dual Culture method was used as an inhibition test between Streptomyces sp. and C. acutatum in vitro. A well diffusion method was used to test the effectiveness of the Streptomyces sp. and MIC filtrate concentration in inhibiting C. acutatum. The data obtained in this study were analyzed with Analysis of Varian (ANOVA) then continued with Duncan Multiple Range Test with 5% significance. Five Streptomyces isolates were found, namely Streptomyces sp.1, Streptomyces sp.2, Streptomyces sp.3, Streptomyces sp.4, and Streptomyces sp.5 in the rhizosphere of healthy C. annum L. plants in Daup Village, Kintamani District, Bangli Regency. Streptomyces sp. isolates. can significantly inhibit the growth of the fungus C. acuatum with inhibitory power ranging from 50.30% to 83.76%, Streptomyces sp.5 isolate was able to provide the highest percentage of inhibition in C. acutatum of 83.76 ± 2.91% with MIC 7% (v/v) with a diameter of 6.40 mm.


1995 ◽  
Vol 37 (4) ◽  
pp. 291-296
Author(s):  
Claudio Tavares Sacchi ◽  
Ana Paula Silva de Lemos ◽  
Silvana Tadeu Casagrande ◽  
Alice Massumi Mori ◽  
Carmecy Lopes de Almeida

In the present study we report the results of an analysis, based on ribotyping of Corynebacterium diphtheriae intermedius strains isolated from a 9 years old child with clinical diphtheria and his 5 contacts. Quantitative analysis of RFLPs of rRNA was used to determine relatedness of these 7 C.diphtheriae strains providing support data in the diphtheria epidemiology. We have also tested those strains for toxigenicity in vitro by using the Elek's gel diffusion method and in vivo by using cell culture method on cultured monkey kidney cell (VERO cells). The hybridization results revealed that the 5 C.diphtheriae strains isolated from contacts and one isolated from the clinical case (nose case strain) had identical RFLP patterns with all 4 restriction endonucleases used, ribotype B. The genetic distance from this ribotype and ribotype A (throat case strain), that we initially assumed to be responsible for the illness of the patient, was of 0.450 showing poor genetic correlation among these two ribotypes. We found no significant differences concerned to the toxin production by using the cell culture method. In conclusion, the use of RFLPs of rRNA gene was successful in detecting minor differences in closely related toxigenic C.diphtheriae intermedius strains and providing information about genetic relationships among them.


Molecules ◽  
2020 ◽  
Vol 25 (20) ◽  
pp. 4856
Author(s):  
Liza Józsa ◽  
Zoltán Ujhelyi ◽  
Gábor Vasvári ◽  
Dávid Sinka ◽  
Dániel Nemes ◽  
...  

Natural products used in the treatment of acne vulgaris may be promising alternative therapies with fewer side effects and without antibiotic resistance. The objective of this study was to formulate creams containing Spirulina (Arthrospira) platensis to be used in acne therapy. Spirulina platensis belongs to the group of micro algae and contains valuable active ingredients. The aim was to select the appropriate nonionic surfactants for the formulations in order to enhance the diffusion of the active substance and to certify the antioxidant and antibacterial activity of Spirulina platensis-containing creams. Lyophilized Spirulina platensis powder (SPP) was dissolved in Transcutol HP (TC) and different types of nonionic surfactants (Polysorbate 60 (P60), Cremophor A6:A25 (CR) (1:1), Tefose 63 (TFS), or sucrose ester SP 70 (SP70)) were incorporated in creams as emulsifying agents. The drug release was evaluated by the Franz diffusion method and biocompatibility was tested on HaCaT cells. In vitro antioxidant assays were also performed, and superoxide dismutase (SOD) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays were executed. Antimicrobial activities of the selected compositions were checked against Staphylococcus aureus (S. aureus) and Cutibacteriumacnes (C. acnes) (formerly Propionibacterium acnes) with the broth microdilution method. Formulations containing SP 70 surfactant with TC showed the most favorable dissolution profiles and were found to be nontoxic. This composition also showed significant increase in free radical scavenger activity compared to the blank sample and the highest SOD enzyme activity was also detected after treatment with the cream samples. In antibacterial studies, significant differences were observed between the treated and control groups after an incubation time of 6 h.


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