scholarly journals Antagonistic Potential of Novel Endophytic Bacillus Strains and Mediation of Plant Defense against Verticillium Wilt in Upland Cotton

Plants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1438
Author(s):  
Nadeem Hasan ◽  
Ayaz Farzand ◽  
Zhou Heng ◽  
Irfan Ullah Khan ◽  
Anam Moosa ◽  
...  
Keyword(s):  
Verticillium Wilt ◽  
Economic Loss ◽  
Antagonistic Activity ◽  
Dual Culture ◽  
Gene Products ◽  
Methanolic Extracts ◽  
Dual Culture Assay ◽  
Antagonistic Potential ◽  
Encoding Genes ◽  
Bacillus Strains

Verticillium wilt caused by Verticillium dahliae is a threatening disease of cotton, causing economic loss worldwide. In this study, nine endophytic Bacillus strains isolated from cotton roots exhibited inhibitory activity against V. dahliae strain VD-080 in a dual culture assay. B. altitudinis HNH7 and B. velezensis HNH9 were chosen for further experiments based on their high antagonistic activity. The secondary metabolites of HNH7 and HNH9 also inhibited the growth of VD-080. Genetic marker-assisted detection revealed the presence of bacillibactin, surfactin, bacillomycin and fengycin encoding genes in the genome of HNH7 and HNH9 and their corresponding gene products were validated through LC-MS. Scanning electron microscopy revealed mycelial disintegration, curling and shrinkage of VD-080 hyphae after treatment with methanolic extracts of the isolated endophytes. Furthermore, a significant reduction in verticillium wilt severity was noticed in cotton plants treated with HNH7 and HNH9 as compared to control treatments. Moreover, the expression of defense-linked genes, viz., MPK3, GST, SOD, PAL, PPO and HMGR, was considerably higher in plants treated with endophytic Bacillus strains and inoculated with VD-080 as compared to control.

scholarly journals Weed-Associated Fungal Endophytes as Biocontrol Agents of Fusariumoxysporum f. sp. cubense TR4 in Cavendish Banana

2021 ◽  
Vol 7 (3) ◽  
pp. 224
Author(s):  
Dennice G. Catambacan ◽  
Christian Joseph R. Cumagun
Keyword(s):  
Fusarium Oxysporum ◽  
Inhibitory Activity ◽  
Disease Incidence ◽  
Fungal Endophytes ◽  
Antagonistic Activity ◽  
Dual Culture ◽  
Trichoderma Asperellum ◽  
Cavendish Banana ◽  
Leaf Yellowing ◽  
Dual Culture Assay

The antagonistic activity of fungal endophytes isolated from weeds growing in Cavendish banana farms was determined against Fusarium oxysporum f. sp. cubense TR4 (Foc TR4) causing Fusarium wilt of Cavendish banana. Forty-nine out of the total 357 fungal endophytes from the roots of weeds exhibited antagonistic activity against Foc TR4. High inhibitory activity at 79.61–99.31% based on dual culture assay was recorded in endophytes Lasiodiplodia theobromae TDC029, Trichoderma asperellum TDC075, Ceratobasidium sp. TDC037, Ceratobasidium sp. TDC241, and Ceratobasidium sp. TDC474. All five endophytes were identified through DNA sequencing with 86–100% identity. Endophyte-treated Grand Naine and GCTCV 218 plantlets showed significantly lower disease incidence (p = 0.014), significantly lower degree of leaf yellowing (p = 0.037) and rhizome discoloration (p = 0.003). In addition, the cultivar Grand Naine was consistently highly susceptible compared with the tolerant cultivar GCTCV 218.

scholarly journals In-vitro Evaluation of Actinobacteria for its Potential in Bio-control of Fungal Plant Pathogens

2019 ◽  
Vol 7 (1) ◽  
pp. 82-87
Author(s):  
Zothan puia ◽  
◽  
W. Carrie ◽  
V.V. Leo ◽  
A.K. Passari ◽  
...  
Keyword(s):  
Plant Pathogens ◽  
Control Strategies ◽  
Dual Culture ◽  
Inhibition Activity ◽  
Fungal Plant Pathogens ◽  
Basic Understanding ◽  
Dual Culture Assay ◽  
Antagonistic Potential ◽  
Fungal Phytopathogens

Infections caused by fungal plant pathogens are recently recognized as a threat to food security worldwide and its control strategies need to be taken care where naturally synthesized fungicides such as those obtained from actinobacteria are becoming an area of great interest. A total of 68 isolates of actinobacteria were evaluated for their antagonistic potential against four fungal plant pathogens viz., Fusarium oxysporum CABI-293942, Fusarium udum MTCC-2755, Fusarium proliferatum MTCC-286 and Fusarium graminearum MTCC-1893 by dual culture assay. It was found that 83.8% of the isolates showed inhibitory activity against at least one of the tested plant pathogens with the percentage of inhibition ranging from 20–87.2. Thirteen Streptomyces isolates and one Nocardiposis isolate exhibited inhibition activity against all the tested pathogens. Overall, this study gives a basic understanding of the potential aspect of freshwater sediments derived actinobacteria against fungal phytopathogens.

scholarly journals Screening of antagonistic activity of microorganisms against Colletotrichum acutatum and Colletotrichum gloeosporioides

2010 ◽  
Vol 62 (3) ◽  
pp. 611-623 ◽  
Author(s):  
Svetlana Zivkovic ◽  
S. Stojanovic ◽  
Z. Ivanovic ◽  
V. Gavrilovic ◽  
Tatjana Popovic ◽  
...  
Keyword(s):  
Colletotrichum Gloeosporioides ◽  
Antagonistic Activity ◽  
Colletotrichum Acutatum ◽  
Dual Culture ◽  
Streptomyces Species ◽  
Anthracnose Disease ◽  
Streptomyces Noursei ◽  
Dual Culture Assay ◽  
Streptomyces Natalensis

The antagonistic activities of five biocontrol agents: Trichoderma harzianum, Gliocladium roseum, Bacillus subtilis, Streptomyces noursei and Streptomyces natalensis, were tested in vitro against Colletotrichum acutatum and Colletotrichum gloeosporioides, the causal agents of anthracnose disease in fruit crops. The microbial antagonists inhibited mycelial growth in the dual culture assay and conidial germination of Colletotrichum isolates. The two Streptomyces species exhibited the strongest antagonism against isolates of C. acutatum and C. gloeosporioides. Microscopic examination showed that the most common mode of action was antibiosis. The results of this study identify T. harzianum, G. roseum, B. subtilis, S. natalensis and S. noursei as promising biological control agents for further testing against anthracnose disease in fruits. .

scholarly journals Klebsiella Phage ΦK64-1 Encodes Multiple Depolymerases for Multiple Host Capsular Types

2017 ◽  
Vol 91 (6) ◽  
Author(s):  
Yi-Jiun Pan ◽  
Tzu-Lung Lin ◽  
Ching-Ching Chen ◽  
Yun-Ting Tsai ◽  
Yi-Hsiang Cheng ◽  
...  
Keyword(s):  
Sequence Similarity ◽  
Amino Acid Sequence Similarity ◽  
Gene Products ◽  
Capsular Type ◽  
Expression And Purification ◽  
Content Type ◽  
Infection Mechanisms ◽  
Host Infection ◽  
Encoding Genes ◽  
Tail Fibers

ABSTRACT The genome of the multihost bacteriophage ΦK64-1, capable of infecting Klebsiella capsular types K1, K11, K21, K25, K30, K35, K64, and K69, as well as new capsular types KN4 and KN5, was analyzed and revealed that 11 genes (S1-1, S1-2, S1-3, S2-1, S2-2, S2-3, S2-4, S2-5, S2-6, S2-7, and S2-8) encode proteins with amino acid sequence similarity to tail fibers/spikes or lyases. S2-5 previously was shown to encode a K64 capsule depolymerase (K64dep). Specific capsule-degrading activities of an additional eight putative capsule depolymerases (S2-4 against K1, S1-1 against K11, S1-3 against K21, S2-2 against K25, S2-6 against K30/K69, S2-3 against K35, S1-2 against KN4, and S2-1 against KN5) was demonstrated by expression and purification of the recombinant proteins. Consistent with the capsular type-specific depolymerization activity of these gene products, phage mutants of S1-2, S2-2, S2-3, or S2-6 lost infectivity for KN4, K25, K35, or K30/K69, respectively, indicating that capsule depolymerase is crucial for infecting specific hosts. In conclusion, we identified nine functional capsule depolymerase-encoding genes in a bacteriophage and correlated activities of the gene products to all ten hosts of this phage, providing an example of type-specific host infection mechanisms in a multihost bacteriophage. IMPORTANCE We currently identified eight novel capsule depolymerases in a multihost Klebsiella bacteriophage and correlated the activities of the gene products to all hosts of this phage, providing an example of carriage of multiple depolymerases in a phage with a wide capsular type host spectrum. Moreover, we also established a recombineering system for modification of Klebsiella bacteriophage genomes and demonstrated the importance of capsule depolymerase for infecting specific hosts. Based on the powerful tool for modification of phage genome, further studies can be conducted to improve the understanding of mechanistic details of Klebsiella phage infection. Furthermore, the newly identified capsule depolymerases will be of great value for applications in capsular typing.

scholarly journals In vitro and in vivo Assay for Assessment of the Biological Control Potential of Streptomyces sp. KT

2017 ◽  
Vol 7 (1) ◽  
pp. 10
Author(s):  
Tatsuya Ohike ◽  
Minori Maeda ◽  
Tetsuya Matsukawa ◽  
Masahiro Okanami ◽  
Shin’ichiro Kajiyama ◽  
...  
Keyword(s):  
Biological Control ◽  
Suppressive Effect ◽  
Phytopathogenic Fungi ◽  
Dual Culture ◽  
Biological Control Agents ◽  
Bipolaris Oryzae ◽  
Biological Control Potential ◽  
Dual Culture Assay

Rhizoctonia solani is fungal plant pathogen that infects many different host plants. Recently, biological control agents that are friendly to the environment and ecosystems have attracted much attention as an alternative to the use of chemical fungicide which have been used worldwide to control soil borne pathogens including R. solani. In this study, 53 strains of actinomycetes isolated from environmental soils, and antifungal activities of them were assessed by the dual culture assay. Strain KT showed strong inhibitory activities against 8 phytopathogenic fungi. A great suppressive effect on R. solani growth was observed in the inoculation test of plants using cucumber and chin-geng-sai. In addition, infection of Bipolaris oryzae also could be suppressed in the detached leaf assay using oats. As a result of genetic analysis, it was shown that KT was a species closely related to Streptomyces lavenduligriseus NRRL B-3173T. However, as far as we know, there is no report for biological control agents using S. lavenduligriseus. This study suggests that the strain KT may useful as biological control agents to suppress various crop diseases.

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 Glycerol Enhances the Antifungal Activity of Dairy Propionibacteria

2010 ◽  
Vol 2010 ◽  
pp. 1-9 ◽  
Author(s):  
Helena Lind ◽  
Anders Broberg ◽  
Karin Jacobsson ◽  
Hans Jonsson ◽  
Johan Schnürer
Keyword(s):  
Propionic Acid ◽  
Starter Cultures ◽  
Dual Culture ◽  
Penicillium Roqueforti ◽  
Glycerol Conversion ◽  
Antifungal Effect ◽  
Dual Culture Assay ◽  
Penicillium Commune ◽  
Dairy Propionibacteria ◽  
Type Strains

Dairy propionibacteria are widely used in starter cultures for Swiss type cheese. These bacteria can ferment glucose, lactic acid, and glycerol into propionic acid, acetic acid, and carbon dioxide. This research examined the antifungal effect of dairy propionibacteria when glycerol was used as carbon source for bacterial growth. Five type strains of propionibacteria were tested against the yeastRhodotorula mucilaginosaand the moldsPenicillium communeandPenicillium roqueforti. The conversion of13C glycerol byPropionibacterium jenseniiwas followed with nuclear magnetic resonance. In a dual culture assay, the degree of inhibition of the molds was strongly enhanced by an increase in glycerol concentrations, while the yeast was less affected. In broth cultures, decreased pH in glycerol medium was probably responsible for the complete inhibition of the indicator fungi. NMR spectra of the glycerol conversion confirmed that propionic acid was the dominant metabolite. Based on the results obtained, the increased antifungal effect seen by glycerol addition to cultures of propionibacteria is due to the production of propionic acid and pH reduction of the medium.

scholarly journals Screening of endophytes from rubber trees (hevea brasiliensis) for biological control of Corticium salmonicolor

2020 ◽  
Vol 8 (2) ◽  
pp. 38-44
Author(s):  
Nguyen Van Minh ◽  
Mai Huu Phuc ◽  
Duong Nhat Linh ◽  
Tran Thi A Ni ◽  
Tran Kien Duc ◽  
...  
Keyword(s):  
Biological Control ◽  
Hevea Brasiliensis ◽  
Endophytic Bacteria ◽  
Rubber Tree ◽  
Antagonistic Activity ◽  
Ho Chi Minh City ◽  
Viet Nam ◽  
Dual Culture ◽  
Living Tissue ◽  
Tissue Samples

28 leaves and living-tissue samples of rubber tree (Hevea brasiliensis) were collected from Ho Chi Minh City, Binh Phuoc province and Binh Duong province (Viet Nam). We isolated and screened endophytes that have potential application as agents for biocontrol of Corticium salmonicolor, the agent of Pink Disease in rubber trees. As a result, 21 strains of endophytic bacteria and 14 strains of endophytic fungi were isolated. Antagonistic activity of the endophytes towards C. salmonicolor was checked by using a dual culture. Testing results showed that: T9, T15 and T16 strains have inhibited C. salmonicolor. T9 and T16 strains showed result that 100% of inhibiting C. salmonicolor at the concentration of 1:1. In the test of ability to kill C. salmonicolor, T9 and T16 strains showed that they could kill C. salmonicolor after 3 sprays of bacterial filtrate. T9 and T6 strains, which were identified by biochemical methods, have similar characteristics to Bacillus thuringiensis.

scholarly journals ​Antagonistic Activity of Panchagavya and Trichoderma spp. against Wilt Complex causing Pathogens of Chickpea (Cicer arietinum L.)

2022 ◽  
Author(s):  
H.V. Parmar ◽  
N.M. Gohel
Keyword(s):  
Low Cost ◽  
Trichoderma Viride ◽  
Macrophomina Phaseolina ◽  
Antagonistic Activity ◽  
Culture Technique ◽  
Plant Diseases ◽  
Dual Culture ◽  
Trichoderma Spp ◽  
Soil Borne Pathogens ◽  
Chickpea Wilt

Background: Chickpea wilt complex caused by several soil-borne pathogens is the major yield-reducing malady worldwide. Biological control is one of the best, low-cost and ecologically sustainable method for managing plant diseases caused by soil-borne pathogens. Methods: In this present investigation Panchagavya and Trichoderma spp. were evaluated by following poisoned food technique and dual culture technique against wilt complex causing pathogens i.e. Fusarium oxysporum f. sp. ciceri, Fusarium solani and Macrophomina phaseolina. Result: Among the different isolates of Trichoderma spp. evaluated, Trichoderma viride (AAU isolate) was highly antagonistic to F. oxysporum f. sp. ciceri (52.78%) and F. solani (65.37%) whereas, Trichoderma asperellum (AAU isolate) was highly antagonistic to M. phaseolina (65.93%). Panchagavya at the highest concentration (50%) showed significantly higher efficacy (80.74, 66.62 and 49.67%) in inhibiting the mycelial growth of all three pathogens and at the lowest concentration it was moderately effective.

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