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 The influence of cultivation conditions of promising Bacillus subtilis strains on their ability to produce antifungal metabolites

2020 ◽  
Author(s):  
T. M. Sidorova ◽  
A. M. Asaturova ◽  
A. I. Khomyak
Keyword(s):  
Bacillus Subtilis ◽  
Nutrient Medium ◽  
Antifungal Compounds ◽  
Cultivation Temperature ◽  
Cultivation Conditions ◽  
Iturin A ◽  
Antifungal Metabolites ◽  
Medium Acidity

Antifungal compounds, including surfactin and iturin A, are accumulated by B. subtilis BZR336g strain at the cultivation temperature of 20.0-25.0 °C and the nutrient medium acidity pH8.0, for B. subtilis BZR517 strain these parameters are 30.0-35.0 °C and pH8.0-10.0, respectively.

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.

Cloning, Sequencing, and Characterization of the Genetic Region Relevant to Biosynthesis of the Lipopeptides Iturin A and Surfactin in Bacillus subtilis

2003 ◽  
Vol 47 (4) ◽  
pp. 272-277 ◽  
Author(s):  
Shiyi Yao ◽  
Xuewen Gao ◽  
Norbert Fuchsbauer ◽  
Wolfgang Hillen ◽  
Joachim Vater ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Iturin A ◽  
Genetic Region

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

Influence of the Production of Two Lipopeptides, Iturin A and Surfactin S1, on Oxygen Transfer During Bacillus subtilis Fermentation

1996 ◽  
pp. 571-579
Author(s):  
Choukri Hbid ◽  
Philippe Jacques ◽  
Hary Razafindralambo ◽  
Mpanya Kalonda Mpoyo ◽  
Eric Meurice ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Oxygen Transfer ◽  
Iturin A

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.

scholarly journals Bacillus spp.; perspectiva de su efecto biocontrolador mediante antibiosis en cultivos afectados por fitopatógenos

Nova ◽  
2011 ◽  
Vol 9 (16) ◽  
pp. 177 ◽  
Author(s):  
Cristian Layton ◽  
Edna Maldonado ◽  
Luisa Monroy ◽  
Lucía Constanza Corrales Ramírez MSC ◽  
Ligia Consuelo Sánchez Leal MSC
Keyword(s):  
Bacillus Subtilis ◽  
Fusarium Oxysporum ◽  
Bacillus Sp ◽  
Bacillus Brevis ◽  
Iturin A ◽  
Bacillus Spp

El presente estudio documental evalúa el efecto biocontrolador del género <em>Bacillus sp </em>contra hongos fitopatógenos de plantas, particularmente, a través de relaciones antagónicas inductoras de muerte celular en términos inminentemente naturales. <em>Fusarium oxysporum </em>se encuentra muy relacionado con casos de marchitez vascular y pudrición de raíz en variedad de plantas, obstrucción de los vasos que permiten la circulación vegetal hasta causar amarillamiento de las hojas por imposibilidad en el transporte de nutrientes, causal de grandes pérdidas económicas en el campo agrícola nacional. Se han establecido varios mecanismos para controlar este hongo micelial dentro de las que se encuentran el uso extensivo y variable de agroquímicos y pesticidas, práctica que por sus efectos nocivos con el medio ambiente se ha comenzado a reemplazar por empleo de especies del género <em>Bacillus. </em>La acción biocontroladora de este género bacteriano esta mediada por su perfil bioquímico ya que son productores de múltiples metabolitos biológicamente activos, en el caso de <em>Bacillus subtilis </em>de Iturin A y fengycin y en <em>Bacillus brevis de gramicidina S </em>(1-5) son capaces de inhibir el desarrollo y crecimiento normal de otros microorganismos, lo que sugiere su utilización para el biocontrol de plagas en aras al fortalecimiento de los actuales estándares de calidad en los procesos ambientales.

scholarly journals Activity of Fengycin and Iturin A Isolated From Bacillus subtilis Z-14 on Gaeumannomyces graminis Var. tritici and Soil Microbial Diversity

2021 ◽  
Vol 12 ◽  
Author(s):  
Jiawen Xiao ◽  
Xiaojun Guo ◽  
Xinlei Qiao ◽  
Xuechao Zhang ◽  
Xiaomeng Chen ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Relative Abundance ◽  
Gaeumannomyces Graminis ◽  
Control Effect ◽  
Soil Bacterial Diversity ◽  
Soil Microbial Diversity ◽  
Wheat Seedlings ◽  
Iturin A ◽  
Soil Microbial ◽  
Take All

Bacillus subtilis Z-14 can inhibit phytopathogenic fungi, and is used as a biocontrol agent for wheat take-all disease. The present study used the soil-borne fungus Gaeumannomyces graminis var. tritici (Ggt), which causes wheat take-all disease, and the soil microbial community as indicators, and investigated the antifungal effects of fengycin and iturin A purified from strain Z-14 using high performance liquid chromatography and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, respectively. The results showed that fengycin destroyed the internal structure of Ggt cells by digesting the cytoplasm and organelles, forming vacuoles, and inducing hyphal shrinkage and distortion. Iturin A induced cell wall disappearance, membrane degeneration, intracellular material shrinkage, and hyphal fragmentation. A biocontrol test demonstrated a 100% control effect on wheat take-all when wheat seedlings were treated with fengycin at 100 μg/ml or iturin A at 500 μg/ml. Iturin A and fengycin both reduced the relative abundance of Aspergillus and Gibberella. At the genus level, iturin A reduced the relative abundance of Mortierella and Myrothecium, while fengycin reduced that of Fusarium. Only fengycin treatment for 7 days had a significant effect on soil bacterial diversity.

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