scholarly journals Mycobiota in the Carposphere of Sour and Sweet Cherries and Antagonistic Features of Potential Biocontrol Yeasts

2021 ◽  
Vol 9 (7) ◽  
pp. 1423
Author(s):  
Ramunė Stanevičienė ◽  
Juliana Lukša ◽  
Živilė Strazdaitė-Žielienė ◽  
Bazilė Ravoitytė ◽  
Regina Losinska-Sičiūnienė ◽  
...  
Keyword(s):  
Fungal Pathogens ◽  
Dna Isolation ◽  
Pathogenic Fungi ◽  
Antagonistic Activity ◽  
Rrna Gene ◽  
Sequencing Analysis ◽  
Sweet Cherries ◽  
Postharvest Handling ◽  
Fungal Assemblages ◽  
Dna Fragment

Sour cherries (Prunus cerasus L.) and sweet cherries (P. avium L.) are economically important fruits with high potential in the food industry and medicine. In this study, we analyzed fungal communities associated with the carposphere of sour and sweet cherries that were freshly harvested from private plantations and purchased in a food store. Following DNA isolation, a DNA fragment of the ITS2 rRNA gene region of each sample was individually amplified and subjected to high-throughput NGS sequencing. Analysis of 168,933 high-quality reads showed the presence of 690 fungal taxa. Investigation of microbial ASVs diversity revealed plant-dependent and postharvest handling-affected fungal assemblages. Among the microorganisms inhabiting tested berries, potentially beneficial or pathogenic fungi were documented. Numerous cultivable yeasts were isolated from the surface of tested berries and characterized by their antagonistic activity. Some of the isolates, identified as Aureobasidium pullulans, Metschnikowia fructicola, and M. pulcherrima, displayed pronounced activity against potential fungal pathogens and showed attractiveness for disease control.

scholarly journals Molecular Characterization of Trichoderma spp. Isolates by Internal Transcribed Spacer (ITS) Region Sequencing Technique and its Use as a Biocontrol Agent

2020 ◽  
Vol 14 (1) ◽  
pp. 70-77
Author(s):  
Ziyaul Haque ◽  
Mohammed S. Iqbal ◽  
Ausaf Ahmad ◽  
Mohd S. Khan ◽  
Jyoti Prakash
Keyword(s):  
Internal Transcribed Spacer ◽  
Biocontrol Agent ◽  
Its Region ◽  
Antagonistic Activity ◽  
Rrna Gene ◽  
Dual Culture ◽  
Sequencing Analysis ◽  
Trichoderma Spp ◽  
Sequencing Technique ◽  
Its Region Sequencing

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.

scholarly journals Investigation of antagonistic activities of actinomycetes isolated from Cuc Phuong and Ba Be National Parks against four plant pathogenic fungi

2020 ◽  
Vol 17 (3) ◽  
pp. 527-535
Author(s):  
Nguyen Thi Van ◽  
Dinh Thi Ngoc Mai ◽  
Le Thi Hoang Yen ◽  
Nguyen Hong Minh ◽  
Nguyen Kim Nu Thao
Keyword(s):  
Botrytis Cinerea ◽  
National Parks ◽  
Fungal Pathogens ◽  
Colletotrichum Gloeosporioides ◽  
Phytophthora Capsici ◽  
Sodium Dodecyl ◽  
Pathogenic Fungi ◽  
Antagonistic Activity ◽  
Antagonistic Microorganisms ◽  
Alternaria Sp

Fungal diseases are a huge problem in agriculture, causing serious damage to annual crop yields worldwide. In order to control fungal pathogens in plants, using antagonistic microorganisms is a common approach, especially actinomycetes, as biocontrols considered to be very potential and safe for the environment. With the advantage of high levels of biodiversity, Vietnamese actinomycetes are of a valuable resource for finding strains that are capable of biocontrolling fungal pathogens in plants. Thus, in this study, 70 actinomycete strains were isolated from Cuc Phuong and Ba Be National Parks by four different isolation methods including rehydration centrifugation, sodium dodecyl sulfate – yeast extract, dry heating and dilution methods. Of these, 29 strains (41.4%) belong to rare actinomycete genera including Actinoplanes, Acrocarpospora, Dactylosporangium, Kineosporia, Micromonospora, Nocardia, Nocardiopsis and Pseudonocardia, which are rarely studied in Vietnam. Subsequently, 70 actinomycete strains were subjected to antagonistic activity assays against four highly pathogenic fungi in plants including Alternaria sp., Botrytis cinerea, Colletotrichum gloeosporioides and Phytophthora capsici. The results showed that 80.5% of Streptomyces and 31% of rare actinomyces could inhibit the growth of at least one of the four pathogenic fungal strains. Moreover, ten actinmomycete strains were found to be able to inhibit three types of tested fungal pathogens, simutaneously. Especially, four actinomycete strains (VTCC-A-828, VTCC-A-671, VTCC-A-605, and VTCC-A-69), having the highest antagonistic activity against four fungal pathogens Alternaria sp., Botrytis cinerea, Colletotrichum gloeosporioides and Phytophthora capsici, respectively, were selected. The results in this study indicate the great potential application for Vietnam's microorganisms in the field of plant protection.

scholarly journals Microbiota Associated with Sclerotia of Soilborne Fungal Pathogens – A Novel Source of Biocontrol Agents Producing Bioactive Volatiles

2019 ◽  
Vol 3 (2) ◽  
pp. 125-136 ◽  
Author(s):  
Pascal Mülner ◽  
Alessandro Bergna ◽  
Philipp Wagner ◽  
Dženana Sarajlić ◽  
Barbara Gstöttenmayr ◽  
...  
Keyword(s):  
Fungal Pathogens ◽  
Plant Pathogens ◽  
Control Strategies ◽  
Antagonistic Activity ◽  
Biocontrol Agents ◽  
High Yield ◽  
Rrna Gene ◽  
Strain Collection ◽  
Antifungal Volatiles ◽  
Differential Imaging

Soilborne plant pathogens are an increasing problem in modern agriculture, and their ability to survive long periods in soil as persistent sclerotia makes control and treatment particularly challenging. To develop new control strategies, we explored bacteria associated with sclerotia of Sclerotinia sclerotiorum and Rhizoctonia solani, two soilborne fungi causing high yield losses. We combined different methodological approaches to get insights into the indigenous microbiota of sclerotia, to compare it to bacterial communities of the surrounding environment, and to identify novel biocontrol agents and antifungal volatiles. Analysis of 16S rRNA gene fragment amplicons revealed significant compositional differences in the bacterial microbiomes of Rhizoctonia sclerotia, the unaffected tuber surface and surrounding soil. Moreover, distinctive bacterial lineages were associated with specific sample types. Flavobacteriaceae and Caulobacteraceae were primarily found in unaffected areas, while Phyllobacteriaceae and Bradyrhizobiaceae were associated with sclerotia of R. solani. In parallel, we studied a strain collection isolated from sclerotia of the pathogens for emission of bioactive volatile compounds. Isolates of Bacillus, Pseudomonas, and Buttiauxella exhibited high antagonistic activity toward both soilborne pathogens and were shown to produce novel, not yet described volatiles. Differential imaging showed that volatiles emitted by the antagonists altered the melanized sclerotia surface of S. sclerotiorum. Interestingly, combinations of bacterial antagonists increased inhibition of mycelial growth up to 60% when compared with single isolates. Our study showed that fungal survival structures are associated with a specific microbiome, which is also a reservoir for new biocontrol agents.

Potato-associated bacteria and their antagonistic potential towards plant-pathogenic fungi and the plant-parasitic nematodeMeloidogyne incognita(Kofoid & White) Chitwood

2002 ◽  
Vol 48 (9) ◽  
pp. 772-786 ◽  
Author(s):  
Annette Krechel ◽  
Annekathrin Faupel ◽  
Johannes Hallmann ◽  
Andreas Ulrich ◽  
Gabriele Berg
Keyword(s):  
Fungal Pathogens ◽  
Bacterial Species ◽  
Pathogenic Fungi ◽  
Antagonistic Activity ◽  
Polymorphism Analysis ◽  
Culturable Bacteria ◽  
Streptomyces Species ◽  
Associated Bacteria ◽  
Antagonistic Potential

To study the effect of microenvironments on potato-associated bacteria, the abundance and diversity of bacteria isolated from the rhizosphere, phyllosphere, endorhiza, and endosphere of field grown potato was analyzed. Culturable bacteria were obtained after plating on R2A medium. The endophytic populations averaged 103and 105CFU/g (fresh wt.) for the endosphere and endorhiza, respectively, which were lower than those for the ectophytic microenvironments, with 105and 107CFU/g (fresh wt.) for the phyllosphere and rhizosphere, respectively. The composition and richness of bacterial species was microenvironment-dependent. The occurrence and diversity of potato-associated bacteria was additionally monitored by a cultivation-independent approach using terminal restriction fragment length polymorphism analysis of 16S rDNA. The patterns obtained revealed a high heterogeneity of community composition and suggested the existence of microenvironment-specific communities. In an approach to measure the antagonistic potential of potato-associated bacteria, a total of 440 bacteria was screened by dual testing for in vitro antagonism towards the soilborne pathogens Verticillium dahliae and Rhizoctonia solani. The proportion of isolates with antagonistic activity was highest for the rhizosphere (10%), followed by the endorhiza (9%), phyllosphere (6%), and endosphere (5%). All 33 fungal antagonists were characterized by testing their in vitro antagonistic mechanisms, including their glucanolytic, chitinolytic, pectinolytic, cellulolytic, and proteolytic activity, and by their BOX-PCR fingerprints. In addition, they were screened for their biocontrol activity against Meloidogyne incognita. Overall, nine isolates belonging to Pseudomonas and Streptomyces species were found to control both fungal pathogens and M. incognita and were therefore considered as promising biological control agents. Key words: biocontrol, antagonistic potential, plant-associated bacteria.

scholarly journals Antagonostic effectiveness of Macromycetes against Candida albicans strains and Issatchenkia orientalis

2021 ◽  
Vol 20 (1) ◽  
pp. e760
Author(s):  
Victor Barshteyn ◽  
Tetiana Krupodorova ◽  
Olena Pokas
Keyword(s):  
Candida Albicans ◽  
Fungal Pathogens ◽  
Lentinula Edodes ◽  
Interspecific Interactions ◽  
Pathogenic Fungi ◽  
Antagonistic Activity ◽  
Partial Replacement ◽  
Dual Culture ◽  
Complete Replacement ◽  
Issatchenkia Orientalis

The trend to search novel natural antifungal compounds has recently been increasing. Interspecific interactions between 30 Macromycetes species and fungal pathogens (Issatchenkia orientalis, Candida albicans strains) have been evaluated using dual culture plate assay. Interaction reactions between studied fungi were different: deadlock after mycelia contact or at a distance, overgrowth without initial deadlock, partial or complete replacement after initial deadlock with contact. Domination of replacement (78.7 %) of pathogenic fungi by Macromycetes was established. Complete replacement was almost twice more frequent (30.7 %) than partial replacement (19.3 %). These results clearly indicate effectiveness of Macromycetes against pathogenic fungi via contact antagonism. Strong antagonistic activity with high antagonistic index (AI) was established by xylotrophic species Ganoderma applanatum (AI = 22.5), Lentinula edodes (AI = 21.0), Flammulina velutipes, Irpiciporus litschaueri and Pleurotus ostreatus (AI = 20.5), leaf litter decay fungus Crinipellis schevczenkoi (AI = 21), and soil saprotroph   Lyophyllum shimeji (AI = 21).

scholarly journals ISOLATION AND SELECTION OF INDIGENOUS ANTIFUNGAL MICROORGANISMS AGAINST PATHOGENIC FUNGI OF PEPPER PLANT IN TAY NGUYEN

2018 ◽  
Vol 16 (2) ◽  
pp. 385-392
Author(s):  
Pham Thi Thuy Hoai ◽  
Ton That Huu Dat ◽  
Tran Thi Hong ◽  
Nguyen Thi Kim Cuc ◽  
Tran Dinh Man ◽  
...  
Keyword(s):  
Fungal Pathogens ◽  
Rapid Development ◽  
Control Plant ◽  
Morphological Characteristics ◽  
Pathogenic Fungi ◽  
Plant Diseases ◽  
Rrna Gene ◽  
Pepper Plant ◽  
Bacterial Strains ◽  
Genus Streptomyces

The pathogenic fungi often cause huge impacts on agricultural crops, and occupy over 80% of plant diseases. Fusarium oxysporum and Rhizoctonia solani are fungal pathogens that can lead to rapid development of plant diseases on important crops in Tay Nguyen (e.g., pepper, coffee, rubber, cashew). Therefore, the study of microorganisms with bioactivity against these pathogens is essential to control plant diseases. In this study, we isolated microorganisms from rhizospheres of pepper in Tay Nguyen and screened beneficial microbes against two pathogenic fungi using agar well diffusion assay. Obtained results showed that there are different about isolated microbial density between samples collected from diseased and healthy pepper. The bacterial population is higher in rhizosphere region of healthy pepper than in those of diseased plants. In contrast, fungal density is lower in rhizosphere region of healthy plants than in those of diseased ones. From isolation plates, we selected and purified 391 strains including 236 bacteria, 149 actinomycetes and 6 fungi for screening antifungal activity. Out of isolated microorganisms, 44 strains (36 bacteria, 6 actinomycetes, and 2 fungi) showed antagonistic activity against at least one of two pathogens (F. oxysporum and R. solani), of which 15 isolates showed activity against both fungi. Identification of isolates with highest activity using the 16S rRNA gene sequences showed bacterial strains belonged to different species Enterobacter ludwigii, Pseudomonas fulva, Bacillus subtilis, whereas 2 actinomycetes belonged to the genus Streptomyces: Streptomyces sp. and Streptomyces diastatochromogenes. Identification of the isolated fungus based on morphological characteristics and the 18S rRNA gene sequence revealed that this strain belonged to species Penicillium oxalicum. Our study revealed the potential of the indigenous microorganisms in preventing and controlling plant-pathogenic fungi.

scholarly journals Antifungal Activity of Endophytic Bacteria Associated with Sweet Sorghum (Sorghum bicolor)

2021 ◽  
Vol 53 (1) ◽  
pp. 16-30
Author(s):  
Siti Meliah ◽  
Tri Ratna Sulistiyani ◽  
Puspita Lisdiyanti ◽  
Atit Kanti ◽  
I Made Sudiana ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Sweet Sorghum ◽  
Endophytic Bacteria ◽  
Fungal Pathogens ◽  
Hydrolytic Enzymes ◽  
Antagonistic Activity ◽  
Lytic Enzyme ◽  
Rrna Gene ◽  
Antifungal Compound

The contribution of endophytic bacteria to the wellbeing of plants as biocontrol agents may be due to endophytic bacteria growing in the same niche as phytopathogens. This work was conducted to study the antagonistic activity of endophytic bacteria recovered from sweet sorghum against Sclerotium rolfsii, Fusarium solani, Fusarium oxysporum, Colletotrichum gloeosporioides in vitro and evaluate the mechanisms of these fungal inhibitions. We selected 78 endophytic bacteria from the stem and root of sweet sorghum plants. They were tested for antagonist activity by direct confrontation method. Antifungal compound production and lytic enzyme activity were examined to determine their mechanisms in inhibiting fungal pathogens. Antifungal compound production was checked by detecting the presence of NRPS and PKS genes. Lytic enzyme activity of the bacteria was evaluated by their ability to produce cellulase, chitinase, and protease. Selected bacteria were identified using molecular analysis based on the 16S rRNA gene. 14 out of the 78 tested isolates showed antagonistic activity and two were able to inhibit all four tested fungal strains. Four bacteria, designated as ACIL1, ACNM4, ACNM6, and ATNM4, produced natural products via NRPS pathway, but only one bacterial extract, designated as ACNM4, showed fungal inhibition. Ten isolates were able to produce hydrolytic enzymes. Endophytic bacteria identified as Burkholderia were revealed to have potential as a biocontrol agent.

scholarly journals Survey and Identification of Date Palm Pathogens and Indigenous Biocontrol Agents

Plant Disease ◽  
2020 ◽  
Vol 104 (9) ◽  
pp. 2498-2508
Author(s):  
Resna Nishad ◽  
Talaat A. Ahmed
Keyword(s):  
Endophytic Fungi ◽  
Fungal Pathogens ◽  
Date Palm ◽  
Defense Mechanism ◽  
Pathogenic Fungi ◽  
Antagonistic Activity ◽  
Immune Defense ◽  
Biocontrol Agents ◽  
Antifungal Metabolites ◽  
Different Seasons

Fungal diseases are considered a major threat to plant growth and productivity. However, some beneficial fungi growing in the same environment protect plants from various pathogens, either by secreting antifungal metabolites or by stimulating the host immune defense mechanism. Date palms are susceptible to several fungal pathogens. Nevertheless, information on the pathogenic fungal distribution in date palm fields across different seasons is limited, especially that from Qatar. Therefore, the current study’s aim was to evaluate the pathogenic and beneficial fungal diversity and distribution, including the endophytic fungi from the date palm tissues and root-associated soil fungi, during different seasons, for the identification of indigenous biocontrol agents. Our results showed that the highest number of fungal species was isolated in fall and spring, and pathogenic fungi were isolated mainly in spring. This is the first report that in Qatar, Neodeightonia phoenicum and Thielaviopsis punctulata cause date palm root rot disease, Fusarium brachygibbosum and Fusarium equiseti cause date palm wilting, and N. phoenicum causes diplodia disease in date palm offshoots. The combinations of the fungi that did not frequently occur together in date palm rhizosphere soil were investigated to identify indigenous biocontrol agents. Based on the results, we determined that Trichoderma harzianum and Trichoderma longibrachiatum are effective antagonistic fungi against T. punctulata, N. phoenicum, F. brachygibbosum, and Fusarium solani, qualifying them as potential biocontrol agents. Antagonistic activity of endophytic fungi against the pathogens was tested; except for Ulocladium chartarum, no endophytic fungi showed antagonistic activity against the tested pathogens. [Formula: see text] Copyright © 2020 The Author(s). This is an open access article distributed under the CC BY 4.0 International license .

scholarly journals Rapid electrochemical identification of pathogenic Candida species

2009 ◽  
Vol 58 (9) ◽  
pp. 1182-1189 ◽  
Author(s):  
Alastair Muir ◽  
A. Toby A. Jenkins ◽  
Gordon Forrest ◽  
John Clarkson ◽  
Alan Wheals
Keyword(s):  
Fungal Pathogens ◽  
Limit Of Detection ◽  
Pathogenic Fungi ◽  
18S Rrna Gene ◽  
Fungal Species ◽  
Cross Reactivity ◽  
Its2 Region ◽  
Rrna Gene ◽  
Human Dna ◽  
Species Specific

This study describes the development of a novel assay to detect fungal DNA and identify the most clinically relevant invasive human pathogenic fungi to the species level using oligonucleotide probes, labelled with electrochemically active groups, and solid-state electrodes. A panfungal probe designed against the 18S rRNA gene region, capable of detecting all fungal pathogens tested, and species-specific probes, designed against the ITS2 region for detection of the five Candida species most commonly encountered in the clinical setting (Candida albicans, Candida glabrata, Candida parapsilosis species complex, Candida krusei and Candida tropicalis), are described. When tested with PCR-amplified DNA from both type and clinical strains of the relevant species, the probes were able to positively identify the relevant fungi, indicated by production of a current significantly elevated above the background reading. No cross-reactivity was observed with any of the species-specific probes when compared with nine non-target Candida species or in the presence of human DNA equivalent to an equal number of ITS2 targets. The panfungal probe gave results that were similarly positive against 15 other fungal species and also did not cross-react with human DNA. The limit of detection of the assay was shown to be approximately 1 genome equivalent for all probes using extracted genomic DNA.

scholarly journals In Vitro Antagonistic Activity of Diverse Bacillus Species Against Fusarium culmorum and F. solani Pathogens

2020 ◽  
Vol 14 (1) ◽  
pp. 157-163
Author(s):  
M. Harba ◽  
M. Jawhar ◽  
M.I.E. Arabi
Keyword(s):  
Fungal Pathogens ◽  
Fusarium Culmorum ◽  
Antagonistic Activity ◽  
Broth Culture ◽  
Bacillus Species ◽  
Rrna Gene ◽  
Antagonistic Effects ◽  
Biological Potential ◽  
Potential Activity

Background: Fusarium culmorum and Fusarium solani are economically important fungal pathogens of many plant species causing significant yield losses worldwide. Frequent uses of fungicides are hazardous to humans and the environment. Therefore, in vitro antagonistic activity of diverse Bacillus species isolates with biological potential activity to control these both pathogens should be investigated. Objective: The objectives were to isolate and identify the Bacillus spp., which are potential controls of F. culmorum and F. solani, and to characterize molecularly, at the species level, those isolates that have potential as biocontroller of the pathogens. Methods: The in vitro antagonistic potential of 40 Bacillus isolates against F. culmorum and F. solani was evaluated on the basis of fungal growth inhibition on nutrient broth culture. The colony morphology and the 16S rRNA gene sequencing of Bacillus spp. were used to identify the isolates. Results: Bacillus sp. isolates were identified as B. atrophaeus, B. subtilis, Paenibacillus polymxa, B. amyloliquefaciens, B. simplex and B. tequilensis. They had significant (P<0.05) antagonistic activities against F. culmorum and F. solani isolates as compared to the untreated control. The antagonistic effects varied depending on the Fusarium sp. The bacterial B. subtilis isolates SY116C and SY SY118C provided the most noteworthy result as both strongly inhibited mycelial growth of F. solani by 97.2%, while the B. tequilensis isolate SY145D was the most effective in the formation of inhibition zones against F. culmorum by 75%. Conclusion: It is apparent that Bacillus sp. isolates play an important role in the inhibition of growth of F. culmorum and F. solani, and that the B. subtilis isolates SY116C and SY118C had the highest biological potential activity against these fungi. These antagonistic effects may be important contributors as a biocontrol approach that could be employed as a part of integrated soil pathogen management system.

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