scholarly journals Biological Control Potential of Streptomyces sp. AR10 Producing Albocycline Isolated from Soil around Ant Nest

2018 ◽  
Vol 10 (3) ◽  
pp. 54
Author(s):  
Tatsuya Ohike ◽  
Tetsuya Matsukawa ◽  
Masahiro Okanami ◽  
Shin’ichiro Kajiyama ◽  
Takashi Ano
Keyword(s):  
Biological Control ◽  
Plant Pathogens ◽  
Sequence Similarity ◽  
Antifungal Compound ◽  
Dual Culture ◽  
High Sequence Similarity ◽  
Genus Streptomyces ◽  
Fungal Plant Pathogens ◽  
Biological Control Potential ◽  
Dual Culture Assay

Fifty actinomycetes were isolated from fifteen soil samples and were screened for their antagonism against fungal plant pathogens by dual culture assay, and one of the strain named AR10 was shown to be most effective in suppression of growth of plant pathogen. An antifungal compound of AR10 was extracted, and purified by TLC and HPLC. As a result of NMR and LC-MS analysis, the antifungal compound was identified as albocycline. AR10 suppressed Rhizoctonia damping-off of cucumber in infection control assay. The 16S rDNA sequence of AR10 shows high sequence similarity to those of genus Streptomyces, and the closest similarity was found in the sequence of S. lanatus NBRC 12787T with 98.7% similarity. However, the production of albocycline in Streptomyces closely related to AR10 in the phylogenetic tree has not been reported. Our finding suggests that AR10 can be a candidate for biological control agents.

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 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 Evaluation of in-vitro methods to select effective streptomycetes against toxigenic fusaria

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6905 ◽  
Author(s):  
Elena Maria Colombo ◽  
Cristina Pizzatti ◽  
Andrea Kunova ◽  
Claudio Gardana ◽  
Marco Saracchi ◽  
...  
Keyword(s):  
Plant Pathogens ◽  
Culture Media ◽  
Screening Methods ◽  
Dual Culture ◽  
In Planta ◽  
In Vitro Method ◽  
In Vitro Methods ◽  
Strain Diversity ◽  
Fungal Plant Pathogens

Biocontrol microorganisms are emerging as an effective alternative to pesticides. Ideally, biocontrol agents (BCAs) for the control of fungal plant pathogens should be selected by an in vitro method that is high-throughput and is predictive of in planta efficacy, possibly considering environmental factors, and the natural diversity of the pathogen. The purpose of our study was (1) to assess the effects ofFusariumstrain diversity (N= 5) and culture media (N= 6) on the identification of biological control activity ofStreptomycesstrains (N= 20) againstFusariumpathogens of wheat in vitro and (2) to verify the ability of our in vitro screening methods to simulate the activity in planta. Our results indicate that culture media,Fusariumstrain diversity, and their interactions affect the results of an in vitro selection by dual culture assay. The results obtained on the wheat-based culture media resulted in the highest correlation score (r= 0.5) with the in planta root rot (RR) inhibition, suggesting that this in vitro method was the best predictor of in planta performance of streptomycetes against Fusarium RR of wheat assessed as extension of the necrosis on the root. Contrarily, none of the in vitro plate assays using the media tested could appropriately predict the activity of the streptomycetes against Fusarium foot rot symptoms estimated as the necrosis at the crown level. Considering overall data of correlation, the activity in planta cannot be effectively predicted by dual culture plate studies, therefore improved in vitro methods are needed to better mimic the activity of biocontrol strains in natural conditions. This work contributes to setting up laboratory standards for preliminary screening assays ofStreptomycesBCAs against fungal pathogens.

Development of a strain-specific SCAR marker for the detection of Trichoderma atroviride 11, a biological control agent against soilborne fungal plant pathogens

2001 ◽  
Vol 38 (6) ◽  
pp. 343-350 ◽  
Author(s):  
M. Rosa Hermosa ◽  
Isabel Grondona ◽  
José María Díaz-Mínguez ◽  
Enrique A. Iturriaga ◽  
Enrique Monte
Keyword(s):  
Biological Control ◽  
Plant Pathogens ◽  
Scar Marker ◽  
Biological Control Agent ◽  
Control Agent ◽  
Trichoderma Atroviride ◽  
Fungal Plant Pathogens

scholarly journals The size, shape and specificity of the sugar-binding site of the jacalin-related lectins is profoundly affected by the proteolytic cleavage of the subunits

2002 ◽  
Vol 367 (3) ◽  
pp. 817-824 ◽  
Author(s):  
Corinne HOULÈS ASTOUL ◽  
Willy J. PEUMANS ◽  
Els J.M. van DAMME ◽  
Annick BARRE ◽  
Yves BOURNE ◽  
...  
Keyword(s):  
Binding Site ◽  
Plant Pathogens ◽  
Higher Plants ◽  
Sequence Similarity ◽  
Binding Specificity ◽  
Proteolytic Cleavage ◽  
Carbohydrate Binding ◽  
High Sequence Similarity ◽  
Intracellular Location ◽  
The Impact

Mannose-specific lectins with high sequence similarity to jacalin and the Maclura pomifera agglutinin have been isolated from species belonging to the families Moraceae, Convolvulaceae, Brassicaceae, Asteraceae, Poaceae and Musaceae. Although these novel mannose-specific lectins are undoubtedly related to the galactose-specific Moraceae lectins there are several important differences. Apart from the obvious differences in specificity, the mannose- and galactose-specific jacalin-related lectins differ in what concerns their biosynthesis and processing, intracellular location and degree of oligomerization of the protomers. Taking into consideration that the mannose-specific lectins are widely distributed in higher plants, whereas their galactose-specific counterparts are confined to a subgroup of the Moraceae sp. one can reasonably assume that the galactose-specific Moraceae lectins are a small-side group of the main family. The major change that took place in the structure of the binding site of the diverging Moraceae lectins concerns a proteolytic cleavage close to the N-terminus of the protomer. To corroborate the impact of this change, the specificity of jacalin was re-investigated using surface plasmon resonance analysis. This approach revealed that in addition to galactose and N-acetylgalactosamine, the carbohydrate-binding specificity of jacalin extends to mannose, glucose, N-acetylmuramic acid and N-acetylneuraminic acid. Owing to this broad carbohydrate-binding specificity, jacalin is capable of recognizing complex glycans from plant pathogens or predators.

scholarly journals Diversity of biocontrol agents, isolated from several sources, inhibitory to several fungal plant pathogens

2020 ◽  
Vol 22 (1) ◽  
Author(s):  
Yan Ramona ◽  
IDA BAGUS GEDE DARMAYASA ◽  
ANAK AGUNG NGURAH NARA KUSUMA ◽  
Martin Line
Keyword(s):  
Fungal Pathogens ◽  
Plant Pathogens ◽  
Antagonistic Activity ◽  
Significant Inhibition ◽  
Biocontrol Agents ◽  
Dual Culture ◽  
Rdna Sequences ◽  
Fungal Plant Pathogens ◽  
Mature Compost

Abstract. Ramona Y, Darmayasa IBG, Kusuma AANN, Line MA. 2021. Diversity of biocontrol agents, isolated from several sources, inhibitory to several fungal plant pathogens. Biodiversitas 22: 298-303. This study investigated the inhibitory potential of diversity of antagonist bacteria residing in the rhizosphere zone and mature compost to counter fungal plant pathogens. Soils collected from rhizosphere of lettuce farms in Bali-Indonesia and Tasmania-Australia, mature compost, commercial biocontrol (Dipel®), and laboratory contaminants with significant inhibition against tested fungal pathogens were used as sources of antagonist bacteria. These antagonists were isolated by applying dilution and spread method on trypticase soya agar (TSA) or potato dextrose agar (PDA), and their ability to inhibit Sclerotinia minor, Sclerotinia sclerotiorum, Fusarium spp., and Rhizoctonia solani was assessed in dual culture assays. The results showed that 67 out of more than 100 isolates had antagonistic activity in vitro against at least one of tested fungal pathogens. In the preliminary identification, Bacillus spp. or Pseudomonas spp. were found to be pre-dominant isolates. Following screening studies in a non-replicated glasshouse experiment against S. minor and S. sclerotiorum, 8 of the most promising isolates were further identified using molecular methods based on their 16s rDNA sequences aligned with those deposited at the GeneBank. These 8 isolates were identified as Pseudomonas corrugata, Bacillus megaterium, Bacillus polymyxa, Bacillus mojavensis, Bacillus pumilus, Bacillus thuringiensis, Exiguobacterium acetylicum, and Chryseobacterium indologenes.

scholarly journals Isolation of actinomycetes from maize rhizosphere from Kupang, East Nusa Tenggara Province, and evaluation of their antibacterial, antifungal, and extracellular enzyme activity

2018 ◽  
Vol 23 (1) ◽  
pp. 40
Author(s):  
Umi Fatmawati ◽  
Yulin Lestari ◽  
Anja Meryandini ◽  
Abdjad Asih Nawangsih ◽  
Aris Tri Wahyudi
Keyword(s):  
Extracellular Enzymes ◽  
Sclerotium Rolfsii ◽  
Extracellular Enzyme ◽  
Rrna Gene ◽  
Dual Culture ◽  
Lytic Enzymes ◽  
Genus Streptomyces ◽  
Maize Rhizosphere ◽  
Dual Culture Assay ◽  
The One

Actinomycetes are the one of the components of the rhizospheric microbial population and useful for producing secondary metabolites such as lytic enzymes, antibiotics, and antifungal. The aim of the study was to isolate the actinomycetes from maize rhizosphere collected from Kupang, East Nusa Tenggara. The screening was focused on the actinomycetes that showed the ability to produce antibacterial, antifungal, and extracellular enzymes such as amylase, cellulase, and protease. The actinomycetes were isolated using Humic-Acid Vitamin B (HV) agar media. The antagonistic assay was tested against Escherichia coli, Staphylococcus aureus, Sclerotium rolfsii and Fusarium oxysporum. Isolate JKP-8 was an isolate that showed the highest activity in inhibiting the growth of E. coli and S. aureus bacteria. Isolate JKP-5 showed the highest activity in inhibiting the growth of F.oxysporum. There were no actinomycetes isolates that showed an ability to inhibit the growth of S. rolfsii fungus based on dual culture assay. JKP-3 and JKP-4 isolates exhibited the highest ability to hydrolyze amylum, while JKP-5 and JKP-8 isolates exhibited the highest ability to hydrolyze CMC. The results of the amplification of 16S rRNA gene in selected potential isolates JKP 5 and JKP 8 indicated that both isolates belong to the genus Streptomyces.

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