scholarly journals Antimicrobial activity of extracellular metabolites from antagonistic bacteria isolated from potato (Solanum phureja) crops

2014 ◽  
Vol 40 (3) ◽  
pp. 212-220 ◽  
Author(s):  
Sinar David Granada García ◽  
Antoni Rueda Lorza ◽  
Carlos Alberto Peláez
Keyword(s):  
Antimicrobial Activity ◽  
Cyclic Peptide ◽  
Biological Activities ◽  
Pathogenic Fungi ◽  
Antagonistic Activity ◽  
Solanum Phureja ◽  
Dual Culture ◽  
Crude Extracts ◽  
Extracellular Metabolites

Microorganisms for biological control are capable of producing active compounds that inhibit the development of phytopathogens, constituting a promising tool toob tain active principles that could replace synthetic pesticides. This study evaluatedtheability of severalpotentialbiocontrol microorganismsto produce active extracellular metabolites. In vitro antagonistic capability of 50 bacterial isolates from rhizospheric soils of "criolla" potato (Solanum phureja) was tested through dual culture in this plant with different plant pathogenic fungi and bacteria. Isolates that showed significantly higher antagonistic activity were fermented in liquid media and crude extracts from the supernatants had their biological activities assessed by optical density techniques. Inhibitory effecton tested pathogens was observed for concentrations between 0.5% and 1% of crude extracts. There was a correlation between the antimicrobial activity of extracts and the use of nutrient-rich media in bacteria fermentation. Using a bioguided method, a peptidic compound, active against Fusarium oxysporum, was obtained from the 7ANT04 strain (Pyrobaculum sp.). Analysis by nuclear magnetic resonance and liquid chromatography coupled to mass detector evidenced an 11-amino acid compound. Bioinformatic software using raw mass data confirmed the presence of a cyclic peptide conformed by 11 mostly non-standard amino acids.

scholarly journals ANTAGONISTIC TEST OF RIAU LOCAL FUNGAL ISOLATES AGAINST SOME PATHOGENIC IN CULTIVATED PLANTS

2019 ◽  
Vol 12 (2) ◽  
pp. 124-132
Author(s):  
Nia Safitri ◽  
Atria Martina ◽  
Rodesia Mustika Roza
Keyword(s):  
Fusarium Oxysporum ◽  
Crop Production ◽  
Plant Pathogens ◽  
Pathogenic Fungi ◽  
Culture Method ◽  
Antagonistic Activity ◽  
Cultivated Plants ◽  
Dual Culture ◽  
Trichoderma Sp

Tanaman budi daya merupakan tanaman yang sering diserang oleh cendawan pathogen, sehingga mengakibatkan penurunan populasi dan produksi tanaman. Pengendalian hayati dengan cendawan antagonis merupakan salah satu metode yang paling efektif dan lebih ramah lingkungan dalam menekan pertumbuhan patogen tanaman. Penelitian ini bertujuan untuk menguji aktivitas antagonis cendawan isolat lokal Riau terhadap beberapa cendawan patogen pada tanaman budi daya. Uji antagonis dilakukan secara in vitro dengan metode dual culture menggunakan lima belas cendawan isolat lokal Riau terhadap Fusarium oxysporum f.sp. lycopersici, Ganoderma philippii, G. boninense, Rigidoporus microporus dan Colletotrichum sansevieria. Hasil penelitian menunjukkan bahwa Trichoderma sp. PNE 4 memiliki aktivitas antagonis tertinggi dan isolat FER C1 serta isolat LLB07 hanya memiliki aktivitas antagonis yang tinggi dalam menekan pertumbuhan cendawan patogen. Trichoderma sp. PNE 4 mampu menghambat pertumbuhan miselium F. oxysporum sebesar 85,30%, G. Philippii (100%), G. boninense (100%), dan C. sansevieria (100%). Isolat FER C1 hanya menghambat R. Microporus (50,39%) dan isolat LLB07 menghambat G. philippii (52,20%). Trichoderma sp. PNE 4 merupakan cendawan uji yang terpilih sebagai cendawan antagonis, karena memiliki kemampuan daya hambat  >70%.Abstract Cultivated plants are often attacked by pathogenic fungi resulting in a decline of population and crop production. Biocontrol with antagonistic fungi is one of the most effective and environmentally friendly methods in suppressing the growth of plant pathogens. This study aims to examine the antagonistic activity of local isolates fungi Riau against some pathogenic fungi on cultivated plants. The antagonistic test was performed in vitro by dual culture method using fifteen local isolates fungal Riau against Fusarium oxysporum f.sp. lycopersici, Ganoderma philippii, G. boninense, Rigidoporus microporus and Colletotrichum sansevieria. The results showed that Trichoderma sp. PNE 4 isolate exhibited highest activites and  FER C1 and LLB07 isolates exhibited high activities suppressed the growth of the fungal pathogen. Trichoderma sp. PNE 4 isolate inhibited mycelial growth F. oxysporum (85.30%), G. philippii (100%), G. boninense (100%) and C. sansevieria (100%). FER C1 isolate only inhibited R. microporus (50.39%), and LLB07 isolate inhibited G. philippii (52.20%). Trichoderma sp. PNE 4 isolate is test isolates as fungal antagonistic.

scholarly journals Evaluation of Antifungal Activity of Antagonistic Bacteria against Butt Rot Disease Pathogen of Pineapple

2017 ◽  
Vol 15 (4) ◽  
pp. 283-293 ◽  
Author(s):  
Mat Nawi NURNADIRAH ◽  
Kartini Che Mohd Ramli NENI ◽  
Mohd Yunus Nor YUZIAH
Keyword(s):  
Antifungal Activity ◽  
Pathogenic Fungi ◽  
Culture Method ◽  
Antagonistic Activity ◽  
Dual Culture ◽  
Butt Rot ◽  
Additional Control ◽  
Inhibitory Potential ◽  
Rot Disease

Butt rot disease, caused by Thielaviopsis paradoxa (De Seynes) Hohn., is one of the major diseases in pineapple cultivation in Malaysia. The objectives of this study were to evaluate the antifungal effect of antagonist bacteria against T. paradoxa, a causal agent of butt rot disease, and to observe the mechanism of antifungal activity of tested antagonist bacteria microscopically. In this study, in vitro antifungal potential of 5 antagonist bacteria, namely B1, B2, B3, B4, and B5, were isolated from infected and non-infected soil samples and evaluated using dual culture method against T. paradoxa. The mechanisms of antifungal activities of antagonist bacteria against the pathogen were microscopically observed. All of the bacteria showed inhibitory effects against the pathogenic fungi. B1 bacteria showed the highest inhibitory potential, with 73 % inhibition, followed by B2, B3, B4, and B5, with 71, 57, 56, and 48 % of inhibition compared to control, respectively. The results also showed that B2, B3, and B4 bacteria exhibited positive inhibition towards the pathogen, with more than 50 % percentage inhibition. The development of a new product for use as a biocontrol agent, used as an additional control or used in combination with existing ones, may reduce dependency on chemical control and increase antagonistic activity efficiency.

scholarly journals Antagonistic activity of endophytic bacteria isolated from weed plant against stem end rot pathogen of pitaya in Vietnam

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
The Anh Luu ◽  
Quyet Tien Phi ◽  
Thi Thu Hang Nguyen ◽  
Mai Van Dinh ◽  
Bich Ngoc Pham ◽  
...  
Keyword(s):  
Endophytic Bacteria ◽  
Indole Acetic Acid ◽  
Pathogenic Fungi ◽  
Antagonistic Activity ◽  
Biofilm Production ◽  
Weed Plant ◽  
Seedling Biomass ◽  
Rot Disease ◽  
Positive Results

Abstract Background Fungal stem end rot disease of pitaya caused by Alternaria alternata is one of the most destructive diseases in Binh Thuan province, Vietnam. This study aimed to assess the antagonistic effects of some endophytic bacteria isolated from the weed plant (Echinochloa colonum) against A. alternata. Results A total of 19 endophytic bacteria were isolated and 5 of them presented in vitro antagonistic activity against A. alternata. Of five, strain EC80 significantly inhibited the pathogenic growth with a mean inhibition diameter of 11.88 ± 0.08 mm, while the other four (C79, EC83, EC90, and EC97) showed a weak inhibition. Interestingly, the combination of EC79 and EC80 reduced more biomass of pathogenic fungi than the single one did. EC79 showed positive results for amylase, indole acetic acid (IAA), and biofilm production, whereas EC80 presented positive capabilities for IAA and biofilm production and a negative one for amylase production. In addition, the combined filtrate of EC79 and EC80 presented non-antifungal activity on biocontrol tests in vitro, indicating that bacteria cells played a role in defending against the pathogen. Moreover, both isolates EC79 and EC80 significantly increased seedling biomass than the control. Conclusions The results suggest that those two strains in combination had the potential to be used as a biocontrol agent against A. alternata. More studies should be done in the future to evaluate their efficiency under the field conditions.

scholarly journals Biocontrol potential of Streptomyces sp. CACIS-1.5CA against phytopathogenic fungi causing postharvest fruit diseases

2020 ◽  
Vol 30 (1) ◽  
Author(s):  
Zahaed Evangelista-Martínez ◽  
Erika Anahí Contreras-Leal ◽  
Luis Fernando Corona-Pedraza ◽  
Élida Gastélum-Martínez
Keyword(s):  
Pathogenic Fungi ◽  
Phytopathogenic Fungi ◽  
Antagonistic Activity ◽  
Fruit Rot ◽  
Main Body ◽  
Type I ◽  
Tropical Fruit ◽  
Habanero Pepper ◽  
Antagonistic Microorganisms

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.

scholarly journals Pseudomonas sp. COW3 Produces New Bananamide-Type Cyclic Lipopeptides with Antimicrobial Activity against Pythium myriotylum and Pyricularia oryzae

Molecules ◽  
2019 ◽  
Vol 24 (22) ◽  
pp. 4170 ◽  
Author(s):  
Olumide Owolabi Omoboye ◽  
Niels Geudens ◽  
Matthieu Duban ◽  
Mickaël Chevalier ◽  
Christophe Flahaut ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Genome Mining ◽  
Antagonistic Activity ◽  
Pyricularia Oryzae ◽  
Pseudomonas Sp ◽  
Pythium Myriotylum ◽  
Cyclic Lipopeptides ◽  
Peptide Synthetase ◽  
Kendrick Mass Defect

Pseudomonas species are metabolically robust, with capacity to produce secondary metabolites including cyclic lipopeptides (CLPs). Herein we conducted a chemical analysis of a crude CLP extract from the cocoyam rhizosphere-derived biocontrol strain Pseudomonas sp. COW3. We performed in silico analyses on its whole genome, and conducted in vitro antagonistic assay using the strain and purified CLPs. Via LC-MS and NMR, we elucidated the structures of four novel members of the bananamide group, named bananamides D-G. Besides variability in fatty acid length, bananamides D-G differ from previously described bananamides A-C and MD-0066 by the presence of a serine and aspartic acid at position 6 and 2, respectively. In addition, bananamide G has valine instead of isoleucine at position 8. Kendrick mass defect (KMD) allowed the assignment of molecular formulae to bananamides D and E. We unraveled a non-ribosomal peptide synthetase cluster banA, banB and banC which encodes the novel bananamide derivatives. Furthermore, COW3 displayed antagonistic activity and mycophagy against Pythium myriotylum, while it mainly showed mycophagy on Pyricularia oryzae. Purified bananamides D-G inhibited the growth of P. myriotylum and P. oryzae and caused hyphal distortion. Our study shows the complementarity of chemical analyses and genome mining in the discovery and elucidation of novel CLPs. In addition, structurally diverse bananamides differ in their antimicrobial activity.

scholarly journals In vitro antimicrobial activity of the organic extract of Cladonia substellata Vainio and usnic acid against Staphylococcus spp. obtained from cats and dogs

2017 ◽  
Vol 37 (4) ◽  
pp. 368-378 ◽  
Author(s):  
Jusciêne B. Moura ◽  
Agueda C. de Vargas ◽  
Gisele V. Gouveia ◽  
João J. de S. Gouveia ◽  
Juracy C. Ramos-Júnior ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Biological Activities ◽  
Meca Gene ◽  
Usnic Acid ◽  
Organic Extract ◽  
In Vitro Antimicrobial Activity ◽  
Low Concentrations ◽  
Wide Range ◽  
Staphylococcus Spp

ABSTRACT: Cladonia substellata Vainio is a lichen found in different regions of the world, including the Northeast of Brazil. It contains several secondary metabolites with biological activity, including usnic acid, which has exhibited a wide range of biological activities. The aim of this study was to evaluate the in vitro antimicrobial activity of the organic extract of C. substellata and purified usnic acid. Initially, Staphylococcus spp., derived from samples of skin and ears of dogs and cats with suspected pyoderma and otitis, were isolated and analyzed. In antimicrobial susceptibility testing against Staphylococcus spp., 77% (105/136) of the isolates were resistant to the antimicrobials tested. In the assessment of biofilm production, 83% (113/136) were classified as producing biofilm. In genetic characterization, 32% (44/136) were positive for blaZ, no isolate (0/136) was positive for the mecA gene, and 2% (3/136) were positive for the icaD gene. The in vitro antimicrobial activity of the organic extract of C. substellata and purified usnic acid against Staphylococcus spp. ranged from 0.25mg/mL to 0.0019mg/mL, inhibiting bacterial growth at low concentrations. The substances were more effective against biofilm-producing bacteria (0.65mg/mL-0.42mg/mL) when compared to non-biofilm producing bacteria (2.52mg/mL-2.71mg/mL). Usnic acid and the organic extract of C. substellata can be effective in the treatment of pyoderma and otitis in dogs and cats caused by Staphylococcus spp.

scholarly journals Antibiotic and Biosurfactant Properties of Cyclic Lipopeptides Produced by Fluorescent Pseudomonas spp. from the Sugar Beet Rhizosphere

2002 ◽  
Vol 68 (7) ◽  
pp. 3416-3423 ◽  
Author(s):  
T. H. Nielsen ◽  
D. Sørensen ◽  
C. Tobiasen ◽  
J. B. Andersen ◽  
C. Christophersen ◽  
...  
Keyword(s):  
Amino Acids ◽  
Biological Control ◽  
Cyclic Peptide ◽  
Agricultural Soils ◽  
Pathogenic Fungi ◽  
Growth Media ◽  
Single Strain ◽  
Cyclic Lipopeptides ◽  
Peptide Moiety

ABSTRACT Cyclic lipopeptides (CLPs) with antibiotic and biosurfactant properties are produced by a number of soil bacteria, including fluorescent Pseudomonas spp. To provide new and efficient strains for the biological control of root-pathogenic fungi in agricultural crops, we isolated approximately 600 fluorescent Pseudomonas spp. from two different agricultural soils by using three different growth media. CLP production was observed in a large proportion of the strains (approximately 60%) inhabiting the sandy soil, compared to a low proportion (approximately 6%) in the loamy soil. Chemical structure analysis revealed that all CLPs could be clustered into two major groups, each consisting of four subgroups. The two major groups varied primarily in the number of amino acids in the cyclic peptide moiety, while each of the subgroups could be differentiated by substitutions of specific amino acids in the peptide moiety. Production of specific CLPs could be affiliated with Pseudomonas fluorescens strain groups belonging to biotype I, V, or VI. In vitro analysis using both purified CLPs and whole-cell P. fluorescens preparations demonstrated that all CLPs exhibited strong biosurfactant properties and that some also had antibiotic properties towards root-pathogenic microfungi. The CLP-producing P. fluorescens strains provide a useful resource for selection of biological control agents, whether a single strain or a consortium of strains was used to maximize the synergistic effect of multiple antagonistic traits in the inoculum.

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