Bioactive antifungal metabolites produced by Streptomyces amritsarensis V31 help to control diverse phytopathogenic fungi

2021 ◽  
Author(s):  
Mohammad Shahid ◽  
Bansh Narayan Singh ◽  
Shaloo Verma ◽  
Prassan Choudhary ◽  
Sudipta Das ◽  
...  
Keyword(s):  
Phytopathogenic Fungi ◽  
Antifungal Metabolites

scholarly journals A Metabolomic Study of Epichloë Endophytes for Screening Antifungal Metabolites

Metabolites ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 37
Author(s):  
Krishni Fernando ◽  
Priyanka Reddy ◽  
Kathryn M. Guthridge ◽  
German C. Spangenberg ◽  
Simone J. Rochfort
Keyword(s):  
Phytopathogenic Fungi ◽  
Bioactive Metabolites ◽  
Symbiotic Association ◽  
In Planta ◽  
Vitro Assay ◽  
Antifungal Metabolites ◽  
Bioassay Guided Fractionation ◽  
Toxic Alkaloids ◽  
Epichloë Endophytes

Epichloë endophytes, fungal endosymbionts of Pooidae grasses, are commonly utilized in forage and turf industries because they produce beneficial metabolites that enhance resistance against environmental stressors such as insect feeding and disease caused by phytopathogen infection. In pastoral agriculture, phytopathogenic diseases impact both pasture quality and animal production. Recently, bioactive endophyte strains have been reported to secrete compounds that significantly inhibit the growth of phytopathogenic fungi in vitro. A screen of previously described Epichloë-produced antifeedant and toxic alkaloids determined that the antifungal bioactivity observed is not due to the production of these known metabolites, and so there is a need for methods to identify new bioactive metabolites. The process described here is applicable more generally for the identification of antifungals in new endophytes. This study aims to characterize the fungicidal potential of novel, ‘animal friendly’ Epichloë endophyte strains NEA12 and NEA23 that exhibit strong antifungal activity using an in vitro assay. Bioassay-guided fractionation, followed by metabolite analysis, identified 61 metabolites that, either singly or in combination, are responsible for the observed bioactivity. Analysis of the perennial ryegrass-endophyte symbiota confirmed that NEA12 and NEA23 produce the prospective antifungal metabolites in symbiotic association and thus are candidates for compounds that promote disease resistance in planta. The “known unknown” suite of antifungal metabolites identified in this study are potential biomarkers for the selection of strains that enhance pasture and turf production through better disease control.

Role of chitinase and β-1,3-glucanase activities produced by a fluorescent pseudomonad and in vitro inhibition of Phytophthora capsici and Rhizoctonia solani

2007 ◽  
Vol 53 (2) ◽  
pp. 207-212 ◽  
Author(s):  
Naveen Kumar Arora ◽  
Min Jeong Kim ◽  
Sun Chul Kang ◽  
Dinesh Kumar Maheshwari
Keyword(s):  
Rhizoctonia Solani ◽  
Phytophthora Capsici ◽  
Phytopathogenic Fungi ◽  
Culture Technique ◽  
Dual Culture ◽  
Fluorescent Pseudomonad ◽  
Antifungal Metabolites ◽  
Fluorescent Pseudomonas

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.

scholarly journals Antifungal activity of indigenous bacillus sp. isolate Q3 against marshmallow mycobiota

2011 ◽  
pp. 111-120
Author(s):  
Dragana Josic ◽  
Radmila Pivic ◽  
Snezana Pavlovic ◽  
Sasa Stojanovic ◽  
Goran Aleksic ◽  
...  
Keyword(s):  
Hydrolytic Enzymes ◽  
Pathogenic Fungi ◽  
Phytopathogenic Fungi ◽  
Bacterial Suspension ◽  
Dual Culture ◽  
Seed Infection ◽  
Bacillus Sp ◽  
Antifungal Metabolites ◽  
Parasitic Fungi ◽  
Plant Growth Promoting

Marshmallow is a host of a number of saprophytic and parasitic fungi in Serbia. The seeds of marshmallow are contaminated with fungi from different genera, especially Alternaria and Fusarium, which significantly reduced seed germination and caused seedling decay. In this study we investigate antagnonism of indigenous Bacillus sp. isolate Q3 against marshmallow mycopopulation. Bacillus sp. Q3 was isolated from maize rhizosphere, characterized by polyphasic approch and tested for plant growth promoting treats. Bacillus sp. Q3 produced antifungal metabolites with growth inhibition activity against numerous fungi in dual culture: 61.8% of Alternaria alternata, 74.8% of Myrothecium verrucaria and 33.6% of Sclerotinia sclerotiorum. That effect could be caused by different antifungal metabolites including siderophores, hydrolytic enzymes, organic acids and indole acetic acid (IAA). Suppression of natural marshmallow seed infection by Q3 isolate was observed. The seeds were immersed in different concentrations of bacterial suspension during 2h and their infections by phytopathogenic fungi were estimated. The results showed significant reduction of seed infection by Alternaria spp. The presented results indicate possible application of this isolate as promising biological agent for control of marshmallow seed pathogenic fungi.

scholarly journals Physiological and biochemical aspects of the fungicidal action of promising biocontrol Bacillus subtilis strains against phytopathogenic fungi pp. Fusarium and Pyrenophora

2020 ◽  
Vol 21 ◽  
pp. 00016
Author(s):  
Marina Pavlova ◽  
Anzhela Asaturova ◽  
Valeria Allakhverdian ◽  
Tatyana Sidorova
Keyword(s):  
Bacillus Subtilis ◽  
Culture Fluid ◽  
Phytopathogenic Fungi ◽  
Fungicidal Action ◽  
Iturin A ◽  
Antifungal Metabolites ◽  
Physiological And Biochemical

The article presents some aspects of the interaction between biocontrol Bacillus subtilis strains and phytopathogenic fungi Fusarium and Pyrenophora. The presence of antifungal metabolites complexes in the culture fluid of the strains, including surfactin and iturin A has been found. The nature of the changes in the mycelium of phytopathogenic fungi is examined when co-cultivated with B.subtilis strains.

scholarly journals Chromatographic profiles of antifungal exo- and endometabolites of Bacillus velezensis

2021 ◽  
Vol 2(26) ◽  
pp. 191-199
Author(s):  
T.M. Sidorova ◽  
◽  
A.M. Asaturova ◽  
V.V. Allakhverdyan ◽  
◽  
...  
Keyword(s):  
Antifungal Activity ◽  
Fusarium Oxysporum ◽  
Phytopathogenic Fungi ◽  
Antagonistic Activity ◽  
Active Metabolites ◽  
Fungicidal Action ◽  
Antifungal Metabolites ◽  
Alternaria Sp ◽  
Tlc Analysis

The antifungal activity of the Bacillus bacteria is based on their ability to produce metabolites. Therefore, when selecting a strain that produces an effective biofungicide, it is necessary to assess the metabolism of bacteria. The aim of this work is to isolate exo- and endometabolites of the promising B. velezensis BZR 336g and B. velezensis BZR 517 strains and assess their antifungal activity. Studies were carried out in 2020–2021. The object of the study is a liquid culture of the B. velezensis BZR 336g and B. velezensis BZR 517 strains. Methods of liquid extraction, ascending thin layer chromatography (TLC), bioautography with a test-culture of Fusarium oxysporum var. orthoceras and Alternaria sp. fungi were used to analyze metabolites. The ability of the strains to accumulate a complex of active metabolites showing antifungal effect from fungistatic to fungicidal action was revealed. On the bioautogram of exometabolites, we found two most pronounced zones (Rf 0.18 and 0.29) of Fusarium oxysporum var. orthoceras BZR P1 growth inhibition (fungicide). Zones with Rf 0.58 for B. velezensis BZR 336g and Rf 0.70 for B. velezensis BZR 517 correspond to the test fungus growth retardation (fungistatic). Significant suppression of Alternaria sp. BZR P8 growth was also observed in two zones (Rf 0.18 and 0.29). The use of surfactin, iturin A, fengycin (Sigma-Aldrich®) in the TLC analysis made it possible to detect similar lipopeptides in the composition of metabolite complexes produced by the studied bacteria. It should be noted that the studied strains differed both in their ability to produce metabolites of different structure (can be found when analyzing chromatograms under ultraviolet light) and in their effect on phytopathogenic fungi in vitro. This may indicate possible differences in the mechanism of antagonistic activity of bacteria against phytopathogenic fungi. Thus, B. velezensis BZR 336g and B. velezensis BZR 517 produce a significant set of antifungal metabolites and can be used as strains to produce effective biofungicides.

scholarly journals Antifungal Secondary Metabolites Produced by the Fungal Endophytes: Chemical Diversity and Potential Use in the Development of Biopesticides

2021 ◽  
Vol 12 ◽  
Author(s):  
Kuo Xu ◽  
Xiu-Qi Li ◽  
Dong-Lin Zhao ◽  
Peng Zhang
Keyword(s):  
Natural Products ◽  
Crop Production ◽  
Fungal Endophytes ◽  
Phytopathogenic Fungi ◽  
Chemical Diversity ◽  
Plant Diseases ◽  
Chemical Examination ◽  
Global Food Security ◽  
Antifungal Metabolites ◽  
Potential Use

Plant diseases caused by phytopathogenic fungi can lead to huge losses in the agricultural fields and therefore remain a continuous threat to the global food security. Chemical-based fungicides contributed significantly in securing crop production. However, indiscriminate application of fungicides has led to increased chemical resistance and potential risks to human health and environment. Thus, there is an urgent need for searching for new bioactive natural products and developing them into new biopesticides. Fungal endophytes, microorganisms that reside in the fresh tissues of living plants, are regarded as untapped sources of novel natural products for exploitation in agriculture and/or medicine. Chemical examination of endophytic fungi has yielded enormous antifungal natural products with potential use in the development of biopesticides. This review summarizes a total of 132 antifungal metabolites isolated from fungal endophytes in the past two decades. The emphasis is on the unique chemical diversity of these metabolic products, together with their relevant antifungal properties. Moreover, some “star molecules,” such as griseofulvin and trichothecene, as well as their synthetic derivatives that possess high potential as candidates of new natural fungicides, are also presented herein.

ASSESSMENT OF SOME ABIOTIC FACTORS ON MICROBIAL BIOPRODUCTS USEFUL IN BIOCONTROL OF PHYTOPATHOGENS

2016 ◽  
Vol 5 (3) ◽  
pp. 799-803
Author(s):  
Sergiu Fendrihan ◽  
Sorina Dinu ◽  
Oana Alina Sicuia ◽  
Florica Constantinescu
Keyword(s):  
Abiotic Factors ◽  
Fungal Growth ◽  
Phytopathogenic Fungi ◽  
Antagonistic Activity ◽  
Antagonistic Effect ◽  
Limiting Factors ◽  
Multiplication Rate ◽  
Antifungal Metabolites ◽  
Ph Conditions

The environmental factors may influence the growth of microorganisms, by favoring their growth or slowing their multiplication rate and the synthesis of different metabolites. Parameters such as temperature, aeration, nutrients, pH or tolerance to NaCl can become limiting factors for microorganisms survival. Bacillus subtilis and related species can grow in variable pH conditions, maintaining the cytoplasmically pH in a relatively close range, stable to the synthesis of proteins and nucleic acids.The aim of this work was to assess the influence of some abiotic factors on the biocontrol activity of microbial bioproducts, based on beneficial strains from Bacillus sp.. The bioproducts were tested in vitro against soil borne fungi at different temperatures and pH conditions. The results showed that the antagonistic activity of the biopreparates, tested at 27°C and 25°C, against phytopathogenic fungi released antifungal metabolites which inhibited the fungal growth. Also, when different pH values were analyzed, the results reflected that at pH 5.5 and pH 8.5 the bioproducts maintained the same antagonistic effect as in the control variant (pH 7.0).

scholarly journals Biocontrol of Avocado Dematophora Root Rot by Antagonistic Pseudomonas fluorescens PCL1606 Correlates With the Production of 2-Hexyl 5-Propyl Resorcinol

2006 ◽  
Vol 19 (4) ◽  
pp. 418-428 ◽  
Author(s):  
Francisco M. Cazorla ◽  
Simon B. Duckett ◽  
Ed T. Bergström ◽  
Sadaf Noreen ◽  
Roeland Odijk ◽  
...  
Keyword(s):  
Pseudomonas Fluorescens ◽  
Root Rot ◽  
Hydrolytic Enzymes ◽  
Test System ◽  
Phytopathogenic Fungi ◽  
Antagonistic Activity ◽  
Antifungal Metabolites ◽  
Antifungal Antibiotics ◽  
Biocontrol Activity ◽  
Tn5 Mutants

A collection of 905 bacterial isolates from the rhizospheres of healthy avocado trees was obtained and screened for antagonistic activity against Dematophora necatrix, the cause of avocado Dematophora root rot (also called white root rot). A set of eight strains was selected on the basis of growth inhibitory activity against D. necatrix and several other important soilborne phytopathogenic fungi. After typing of these strains, they were classified as belonging to Pseudomonas chlororaphis, Pseudomonas fluorescens, and Pseudomonas putida. The eight antagonistic Pseudomonas spp. were analyzed for their secretion of hydrogen cyanide, hydrolytic enzymes, and antifungal metabolites. P. chlororaphis strains produced the antibiotic phenazine-1-carboxylic acid and phenazine-1-carboxamide. Upon testing the biocontrol ability of these strains in a newly developed avocado-D. necatrix test system and in a tomato-F. oxysporum test system, it became apparent that P. fluorescens PCL1606 exhibited the highest biocontrol ability. The major antifungal activity produced by strain P. fluorescens PCL1606 did not correspond to any of the major classes of antifungal antibiotics produced by Pseudomonas biocontrol strains. This compound was purified and subsequently identified as 2-hexyl 5-propyl resorcinol (HPR). To study the role of HPR in biocontrol activity, two Tn5 mutants of P. fluorescens PCL1606 impaired in antagonistic activity were selected. These mutants were shown to impair HRP production and showed a decrease in biocontrol activity. As far as we know, this is the first report of a Pseudomonas biocontrol strain that produces HPR in which the production of this compound correlates with its biocontrol activity.

scholarly journals Effect of agitation rate on the production of antifungal metabolites by Streptomyces hygroscopicus in a lab-scale bioreactor

2017 ◽  
pp. 231-244 ◽  
Author(s):  
Ivana Mitrovic ◽  
Jovana Grahovac ◽  
Jelena Dodic ◽  
Mila Grahovac ◽  
Sinisa Dodic ◽  
...  
Keyword(s):  
Inhibition Zone ◽  
Phytopathogenic Fungi ◽  
Plant Diseases ◽  
Streptomyces Hygroscopicus ◽  
Agitation Rate ◽  
Promising Alternative ◽  
Potato Dextrose Agar Medium ◽  
Antifungal Metabolites ◽  
Apple Fruits

The application of antifungal compounds produced by microorganisms in the control of plant diseases caused by phytopathogenic fungi is a promising alternative to synthetic pesticides. Among phytopathogenic fungi, Alternaria alternata and Fusarium avenaceum are significant pathogens responsible for the storage rot of apple fruits. During storage, transport and marketing A. alternata and F. avenaceum can cause significant losses of apple fruits and their control is of great importance for the producers and consumers. In the present study, the effects of agitation rate on the production of antifungal methabolite( s) by Streptomyces hygroscopicus in a 3-L lab-scale bioreactor (Biostat? Aplus, Sartorius AG, Germany) against two isolates of A. alternata and two isolates of F. avenaceum were investigated. The cultivation of S. hygroscopicus was carried out at 27?C with agitation rates of 100 rpm and 200 rpm during 7 days. The aim was to analyze the bioprocess parameters of biofungicide production in a medium containing glycerol as a carbon source, and examine the effect of agitation rate on the production of antifungal metabolite(s). The in vitro antifungal activity of the produced metabolites against fungi from the genera Alternaria and Fusarium grown on potato dextrose agar medium was determined every 24 h using wells technique. In the experiments conducted in the bioreactor at different stirring speeds, it was found that the maximum production of antifungal metabolites occurred after 96 hours of cultivation. A higher consumption of nutrients and a larger inhibition zone diameter was registered in the experiment with an agitation rate of 200 rpm.

scholarly journals Production of plant protection agents in medium containing waste glycerol by Streptomyces hygroscopicus: Bioprocess analysis

2020 ◽  
Vol 49 (3) ◽  
pp. 270-277
Author(s):  
I. Mitrović ◽  
J. Grahovac ◽  
J. Dodić ◽  
A. Jokić ◽  
Z. Rončević ◽  
...  
Keyword(s):  
Plant Protection ◽  
Phytopathogenic Fungi ◽  
Global Market ◽  
Biodiesel Production ◽  
Streptomyces Hygroscopicus ◽  
Diffusion Method ◽  
Agitation Rate ◽  
Antifungal Metabolites ◽  
Waste Glycerol ◽  
Fruit Samples

The surplus of waste glycerol, by-product of the biodiesel production process, is available at the global market. Some species of the genera Streptomyces have the ability to assimilate glycerol and convert it into valuable metabolic products. In the present study, the ability of Streptomyces hygroscopicus to assimilate waste glycerol and convert it into metabolic compounds with antifungal activity against four phytopathogenic fungi obtained from apple fruit samples expressing rot symptoms, was investigated. Production of antifungal metabolites by S. hygroscopicus was carried out in 3 l stirred tank bioreactor through 7 days. Fermentation was carried out at 27 °C with aeration rate of 1.5 vvm and agitation rate of 100 r.p.m. The aim of this work was to analyse bioprocess parameters and to determine at which stage of bioprocess the production of antifungal metabolites occurs. Activity of the cultivation liquid on two isolates of Alternaria alternata and two isolates of Fusarium avenaceum were determined every 12 h using in vitro well diffusion method. It was found that the maximum production of antifungal metabolites occurred at 108 hour of cultivation. Formed inhibition zones have shown that the produced antifungal metabolites have high efficacy on tested phytopathogenic fungi (inhibition zone diameter higher than 35 mm for all test organisms).

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