Inhibitory Effect and Morphological Changes by Organic Acids to Bacterial Strains Causing Sugar Beet Soft Root Rot In Vitro

The antimicrobial action of the dietary supplement Oxidal® was tested using the classic Bauer and Kirby agar-gel diffusion method. Clinical and reference strains of Staphylococcus aureus and Escherichia coli were used in the studies. The tested dietary supplement showed a well-pronounced inhibitory effect against the microbial strains commensurable with that of the broad-spectrum chemotherapeutic agent Enrofloxacin and showed even higher activity than the broad spectrum antibiotic Thiamphenicol. The proven inhibitory effect of the tested dietary supplement against the examined pathogenic bacteria is in accordance with the established clinical effectiveness standards for antimicrobial agents.

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Sensitivity of Rhizoctonia solani AG-2-2 from Sugar Beet to Fungicides

Plant Disease ◽

10.1094/pdis-04-16-0525-re ◽

2016 ◽

Vol 100 (12) ◽

pp. 2427-2433 ◽

Cited By ~ 4

Author(s):

Sahar Arabiat ◽

Mohamed F. R. Khan

Keyword(s):

Sugar Beet ◽

Rhizoctonia Solani ◽

Root Rot ◽

The United States ◽

Damping Off ◽

Growth Assay ◽

The Mean ◽

Crown And Root Rot ◽

Mean Concentration

Rhizoctonia damping-off and crown and root rot caused by Rhizoctonia solani are major diseases of sugar beet (Beta vulgaris L.) worldwide, and growers in the United States rely on fungicides for disease management. Sensitivity of R. solani to fungicides was evaluated in vitro using a mycelial radial growth assay and by evaluating disease severity on R. solani AG 2-2 inoculated plants treated with fungicides in the greenhouse. The mean concentration that caused 50% mycelial growth inhibition (EC50) values for baseline isolates (collected before the fungicides were registered for sugar beet) were 49.7, 97.1, 0.3, 0.2, and 0.9 μg ml−1 and for nonbaseline isolates (collected after registration and use of fungicides) were 296.1, 341.7, 0.9, 0.2, and 0.6 μg ml−1 for azoxystrobin, trifloxystrobin, pyraclostrobin, penthiopyrad, and prothioconazole, respectively. The mean EC50 values of azoxystrobin, trifloxystrobin, and pyraclostrobin significantly increased in the nonbaseline isolates compared with baseline isolates, with a resistant factor of 6.0, 3.5, and 3.0, respectively. Frequency of isolates with EC50 values >10 μg ml−1 for azoxystrobin and trifloxystrobin increased from 25% in baseline isolates to 80% in nonbaseline isolates. Although sensitivity of nonbaseline isolates of R. solani to quinone outside inhibitors decreased, these fungicides at labeled rates were still effective at controlling the pathogen under greenhouse conditions.

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Variations in Pathogenicity of Three Different Forms of Rhizoctonia Inoculum and Assessment of Cultivar Resistance of Sugar Beet

Journal of Pathology & Microbiology ◽

10.26420/jpatholmicrobiol.2021.1019 ◽

2021 ◽

Vol 3 (1) ◽

Author(s):

Haque ME ◽

◽

Parvin MS ◽

Keyword(s):

Seed Germination ◽

Sugar Beet ◽

Root Rot ◽

Large Scale ◽

Culture Media ◽

Damping Off ◽

Require Time ◽

Time Space ◽

The Usa

Rhizoctonia solani causes pre-emergence and post-emergence damping-off, as well as crown and root rot of sugar beet (Beta vulgaris L.), which significantly affects the yield returns in the USA and Europe. The pathogen overwinters as sclerotia or melanized mycelium. Traditionally, the resistance of cultivars to R. solani is evaluated by scoring disease reactions at the crowns and roots of older seedlings, thus resistance is not evaluated during seed germination. Moreover, earlier studies evaluated cultivars resistance to R. solani using colonized whole barley or wheat grains which, unlike sclerotia, are artificial inocula of the pathogen that require time, space and technical know-how to produce. Moreover, colonized grains are prone to contamination with other pathogens, consumed by rodents/birds while applied in the field, and are often uneconomic. Considering those limitations, a study was undertaken (1) to develop in vitro methods to generate large-scale sclerotia, (2) to compare pathogenic potentials of sclerotia, mycelia, and colonized barley grains for optimization of dampingoff assays, and (3) to evaluate Rhizoctonia resistance of selected commercial cultivars during the seed germination phase. Comparing six different culture media, we found that R. solani had the highest radial growth (8.9 ± 0.04, cm³) at 8-days and the maximum number of sclerotia produced (203 ± 4.6) at 28-days in CV8 medium. We demonstrated significant differences in pathogenicity of the three different forms of R. solani inocula and susceptibility of cultivars to preand post-emergence damping-off. The highest pre-emergence damping-off and root rot were observed with sclerotia, and the highest post-emergence dampingoff was recorded with both sclerotial and colonized barley inocula. In addition, varietal differences in susceptibility to pre- and post-emergence damping-off were noted. The highest pre-emergence damping-off was recorded on cv Crystal 101RR and lowest in Maribo MA 504. The highest post-emergence damping-off was recorded on BTS 8500 and the lowest in Crystal 467. The maximum mean root rot was observed in BTS 8500, BTS 8606, and Crystal 101R. Our studies demonstrated that sclerotia serve as efficient natural inocula, reemphasized that host-pathogen interactions differ at the early vs. late stages of sugar beet growth, and highlighted the need to reevaluate commercial sugar beet cultivars for resistance at the seed germination stage.

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Efficacy of Bacterial Seed Treatments for Controlling Pythium Root Rot of Winter Wheat

Plant Disease ◽

10.1094/pdis.1997.81.2.180 ◽

1997 ◽

Vol 81 (2) ◽

pp. 180-184 ◽

Cited By ~ 33

Author(s):

E. A. Milus ◽

C. S. Rothrock

Keyword(s):

Root Rot ◽

Burkholderia Cepacia ◽

Field Conditions ◽

Yield Enhancement ◽

Bacterial Strains ◽

Seed Treatments ◽

Wheat Roots ◽

Commercial Use ◽

Pythium Root Rot

Pythium root rot, caused by various Pythium spp., is a widespread disease of wheat. The objective of this study was to identify bacterial strains from wheat roots in Arkansas that suppressed Pythium root rot and to compare their efficacy with that of bacterial strains from other areas. Bacterial strains (applied as seed treatments) that suppressed Pythium root rot in growth chamber assays were evaluated further for in vitro antibiosis against three Pythium spp. and for efficacy under field conditions. Pseudomonas fluorescens strain 2-79R, Burkholderia cepacia strain 1-23, and Pseudomonas sp. strain 1-30 were the most effective for suppressing Pythium root rot under field conditions and significantly (P = 0.10) increased yield in one experiment. Strains that were effective in the field also expressed in vitro antibiosis to at least two of three Pythium spp.; however, strains expressing the highest levels of antibiosis were not effective in the field. In the field, root rot suppression and yield enhancement were inconsistent across experiments and generally small in magnitude. Therefore, these strains have little potential for commercial use under the conditions in which they were tested.

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Changes in the Density and Composition of Rhizosphere Pathogenic Fusarium and Beneficial Trichoderma Contributing to Reduced Root Rot of Intercropped Soybean

10.21203/rs.3.rs-1067184/v1 ◽

2021 ◽

Author(s):

Xiaoli Chang ◽

Huiting Xu ◽

Li Yan ◽

Dan Zhu ◽

Wei Wang ◽

...

Keyword(s):

Root Rot ◽

Cell Walls ◽

Rhizosphere Soil ◽

Fusarium Species ◽

Inhibitory Effect ◽

Trichoderma Species ◽

Soybean Root ◽

The Difference ◽

Rhizosphere Microbial Community

Abstract BackgroundThe dynamic of soil-borne disease is closely related to the rhizosphere microbial communities. Maize-soybean intercropping can suppress soybean root rot as compared to monoculture. However, it is still unknown whether rhizosphere microbial community participates in the regulation of intercropped soybean root rot.MethodsIn this study, the difference of rhizosphere Fusarium and Trichoderma community was compared between healthy or root-rotted soybean rhizosphere soil from soybean monoculture and maize-soybean intercropping, and the inhibitory effect of potential biocontrol Trichoderma against pathogenic Fusarium were examined.ResultsThe abundance of rhizosphere Fusarium was remarkably different between intercropping and monoculture, while Trichoderma was largely accumulated in healthy rhizosphere soil of intercropping rather than monoculture. Four rhizosphere Fusarium species identified were all pathogenic to soybean but displayed distinct composition and isolation proportion in the corresponding soil types. As the dominant and most aggressive species, F. oxysporum was more frequently isolated in diseased soil of monoculture. Furthermore, of three Trichoderma species identified, T. harzianum dramatically increased in the rhizosphere of intercropping rather than monoculture as compared to T. virens and T. afroharzianum. For in-vitro antagonism test, Trichoderma strains had antagonistic effects on F. oxysporum with the percentage of mycelial inhibition ranging of 50.59%-92.94%, and they displayed good mycoparasitic abilities against F. oxysporum through coiling around and entering into the hyphae, expanding along cell-cell lumen and even dissolving cell walls of target fungus.ConclusionThese results indicate maize-soybean intercropping significantly increase the density and composition proportion of beneficial Trichoderma to antagonist the pathogenic Fusarium species, thus contributing to the suppression of soybean root rot under intercropping.

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Rapid and efficient synthesis of newer heterocyclic 2-azetidinone and 5-benzylidine-4-oxo-thiazolidine compounds and their pharmacological studies

10.31221/osf.io/myjaq ◽

2019 ◽

Author(s):

Chem Int

Keyword(s):

Inhibitory Effect ◽

Diffusion Method ◽

Spectroscopic Techniques ◽

Antimicrobial Compounds ◽

Efficient Synthesis ◽

Proteus Vulgaris ◽

Bacterial Strains ◽

Pharmacological Studies ◽

In Vitro Antibacterial Activity

A straightforward rapid and efficient protocol for the synthesis of 2-azetidinone (D1-10) and 5-benzylidine-4-oxo-thiazolidine (F1-10) has been designed and synthesized in order to find newer antimicrobial compounds. The structure of entitle compounds have been evaluated on the basis of various spectroscopic techniques FTIR, 1H-NMR, 13C-NMR as well as elemental microanalysis. The title compounds were screened for their preliminary in vitro antibacterial activity against a panel of selected pathogenic bacterial strains, Staphylococcus aureus (MTCC 96), Escherichia coli (MTCC 443), Proteus vulgaris (MTCC 426) and Pseudomonas aeruginosa (MTCC 424) using cup-plate agar diffusion method at 40 μg/ml concentration. Out of synthesized compounds, compound nos. D4, D5, D7, D8, D9 and D10 have shown outstanding inhibitory effect against all pathogens and consider as the best bioactive desired antibacterial analogue of the series as compare to standard drugs ampicilline and chloramphenicol.

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In vitro antibacterial activity of Terminalia chebula leaf gall extracts against some human pathogenic strains

International Current Pharmaceutical Journal ◽

10.3329/icpj.v1i8.11254 ◽

2012 ◽

Vol 1 (8) ◽

pp. 217-220 ◽

Cited By ~ 2

Author(s):

BE Ravi Shankara ◽

YL Ramachandra ◽

S Sundara Rajan ◽

J Preetham ◽

PS Sujan Ganapathy

Keyword(s):

Antibacterial Activity ◽

Aqueous Extract ◽

Ethanol Extract ◽

Pharmaceutical Journal ◽

Inhibitory Effect ◽

Diffusion Method ◽

Terminalia Chebula ◽

Bacterial Strains ◽

South Indian

The leaf galls of Terminalia chebula is used widely as Karkatasringi in south Indian markets. Karkatashringi is an important crude drug employed in various indigenous systems of medicine against several diseases and the drug has diverse medicinal properties. The present study was carried out to understand the antimicrobial activity of various extracts. The antibacterial activity of T. chebula (leaf gall) was evaluated against ten bacterial strains including Gram-positive and Gram-negative bacteria using the agar-well diffusion method. Among the two extracts tested, the ethanol extract presented the best results against all the bacteria while aqueous extract showed moderate inhibition of the microbial growth. Each extract is unique against different microorganisms; Staphylococcus aureus was more susceptible to both extract among the tested organisms, whereas Serratia marcescens and Proteus mirabilis were less susceptible for ethanol and aqueous extract respectively. The inhibitory effect of the extracts was compared with standard antibiotic Ciprofloxacin.DOI: http://dx.doi.org/10.3329/icpj.v1i8.11254 International Current Pharmaceutical Journal 2012, 1(8): 217-220

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Characterization of an Exo-β-1,3-Glucanase Produced by Pichia anomala Strain K, Antagonist of Botrytis cinerea on Apples

Phytopathology ◽

10.1094/phyto.1998.88.4.335 ◽

1998 ◽

Vol 88 (4) ◽

pp. 335-343 ◽

Cited By ~ 133

Author(s):

M. Haïssam Jijakli ◽

Philippe Lepoivre

Keyword(s):

Botrytis Cinerea ◽

Culture Media ◽

Morphological Changes ◽

Synthetic Medium ◽

Inhibitory Effect ◽

Pichia Anomala ◽

Cell Swelling ◽

Glucanase Activity ◽

Cell Wall Preparation

The exo-β-1,3-glucanase (EC 3.2.1.58) activity of Pichia anomala strain K, an antagonistic yeast of Botrytis cinerea on postharvest apples, was studied in a synthetic medium supplemented with laminarin, a cell wall preparation (CWP) of B. cinerea, or glucose. The highest enzyme activity was detected in culture media containing a CWP of B. cinerea as the sole carbon source, whereas the lowest activity was observed in culture media supplemented with glucose. Exoglc1, an exo-β-1,3-glucanase, was purified to homogeneity from culture filtrates of strain K containing a CWP. The molecular mass of exoglc1 was estimated to be under 15 kDa. Optimum activity of exoglc1 was recorded at 50°C and pH 5.5. The exoglc1 Km value was estimated at 22.4 mg/ml. Exoglc1 showed in vitro a stronger inhibitory effect on germ tube growth of B. cinerea than on conidia germination and caused morphological changes such as leakage of cytoplasm and cell swelling. Exo-β-1,3-glucanase activity was detected on apples treated with strain K and was similar to exoglc1 on the basis of activity on native gel. Moreover, the addition of a CWP to a suspension of P. anomala stimulated both in situ exo-β-1,3-glucanase activity and protective activity against the pathogen, strengthening the hypothesis that exo-β-1,3-glucanase activity is one of the mechanisms of action involved in the suppression of B. cinerea by P. anomala strain K.

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The influence of plant essential oils on in vitro growth of Pectobacterium and Dickeya spp. bacteria

Acta Scientiarum Polonorum Hortorum Cultus ◽

10.24326/asphc.2021.6.3 ◽

2021 ◽

Vol 20 (6) ◽

pp. 19-29

Author(s):

Małgorzata Schollenberger ◽

Agnieszka Gadomska-Gajadhur ◽

Ewa Mirzwa-Mróz ◽

Damian Kret ◽

Ewa Skutnik ◽

...

Keyword(s):

Essential Oils ◽

Soft Rot ◽

Inhibitory Effect ◽

Diffusion Method ◽

Juniperus Virginiana ◽

Bacterial Strains ◽

Disk Diffusion Method ◽

First Report ◽

Plant Essential Oils

The activity of essential oils from Eucalyptus globulus, Pinus silvestris, Lavandula angustifolia, Juniperus virginiana, Rosmarinus officinalis and Citrus paradise against the soft-rot pathogens Pectobacterium carotovorum subsp. carotovorum, Pectobacterium atrosepticum, Pectobacterium parmentieri and Dickeya solani was determined in vitro. The antibacterial activity of the essential oils will be evaluated using the disk-diffusion method by Kirby-Bauer [Bauer et al. 1966]. It was found that all the presented essential oils varied in antimicrobial activity against the four bacterial strains. No differences in the influence of streptomycin on inhibition of growth of the four bacterial strains were observed. Among six tested plants, essential oils from P. sylvestris had the strongest inhibitory effect on the growth of soft rot bacteria from Pectobacterium genus. This paper constitute the first report on the activity of the essential oils obtained from J. virginiana against soft rot bacteria. They are also the first report on the activity of the essential oils obtained from E. globulus, P. silvestris, L. angustifolia and C. paradisi against P. atrosepticum, P. parmentieri and D. solani as well as on the activity of the R. officinalis essential oils against P. atrosepticum and P. parmentieri.

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Abundant Extractable Metabolites from Temperate Tree Barks: The Specific Antimicrobial Activity of Prunus Avium Extracts

Antibiotics ◽

10.3390/antibiotics9030111 ◽

2020 ◽

Vol 9 (3) ◽

pp. 111 ◽

Cited By ~ 2

Author(s):

Amin Abedini ◽

Marius Colin ◽

Jane Hubert ◽

Emilie Charpentier ◽

Apostolis Angelis ◽

...

Keyword(s):

Prunus Avium ◽

Lethal Effect ◽

Antimicrobial Activities ◽

Inhibitory Effect ◽

Major Constituent ◽

Bacterial Strains ◽

Gram Positive Bacteria ◽

Tree Barks ◽

13C Nuclear Magnetic Resonance

Tree barks are mainly considered as wood wastes from forestry activities, but represent valuable resources as they may contain antimicrobial compounds. Here, we aimed to evaluate the possible antimicrobial activities of bark extracts and to characterize the chemical composition of the most active extract. Ten methanol bark extracts were tested in vitro against 17 bacterial strains and 5 yeast strains, through minimum inhibitory concentration (MIC) and minimum bactericidal (or fungicidal) concentration (MBC/MFC) assays. The extract from Prunus avium (E2-4) displayed the largest bactericidal activity against Gram-positive bacteria, with a lethal effect on 6 out of 8 strains. Antibiofilm assays of E2-4 were performed by crystal violet staining and enumeration of adhered bacteria. Assays demonstrated a biofilm inhibitory effect of E2-4 against Staphylococcus aureus CIP 53.154 at concentrations equal to or higher than 250 µg/mL. Chemical profiling of E2-4 by 13C nuclear magnetic resonance (NMR) revealed the presence of dihydrowogonin as a major constituent of the extract. E2-4 was fractionated by centrifugal partition chromatography and the three fractions containing dihydrowogonin were tested for their antibacterial and antibiofilm activities, revealing similar activities to those of E2-4. Dihydrowogonin was positively assessed as an interesting antimicrobial compound, which could be valued from wastes of Prunus avium barks.

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