scholarly journals Immobilized Bacillus subtilis by ionic gelation as biocontrol alternative of Fusarium oxysporum f.sp. lycopersici

2018 ◽  
Author(s):  
Castañeda Alvarez Estefania ◽  
Sánchez Leal Ligia
Keyword(s):  
Biological Control ◽  
Bacillus Subtilis ◽  
Fusarium Oxysporum ◽  
Sodium Alginate ◽  
Ionic Gelation ◽  
Cellular Viability ◽  
Market Demand ◽  
Control Activity ◽  
Pests And Diseases

For farmers the use of agrochemicals is the preferred method to control pests and diseases. Considering the market demand for biological control products, the encapsulation could be a competent alternative to current commercial formulations for cellular viability and controlled release. The purpose of this study was to use ionic gelation with sodium alginate, starch and maltodextrin to immobilize Bacillus subtilis and to evaluate the biocontrol effect against Fusarium oxysporum f. sp. lycopersici in vitro. The matrix with a concentration of 2% sodium alginate, 1% starch, and 1% maltodextrin is a suitable method for cellular viability and biological control activity against Fusarium oxysporum f. sp. lycopersici, with a reduction of mycelial growth of 49.6% and a survival rate for Bacillus subtilis of 98.05% (p less than 0.0001).The use of immobilized bacteria as biological control agents are sustainable and effective bio-inputs that could be used at industrial scale and benefit the tomato crops against attack by Fusarium oxysporum f. sp. lycopersici.

Biological control of Fusarium wilt of cucumber with nonpathogenic isolates of Fusarium oxysporum

1987 ◽  
Vol 33 (5) ◽  
pp. 349-353 ◽  
Author(s):  
T. C. Paulitz ◽  
C. S. Park ◽  
R. Baker
Keyword(s):  
Biological Control ◽  
Fusarium Oxysporum ◽  
Infection Rate ◽  
Fusarium Wilt ◽  
Disease Incidence ◽  
Infection Rates ◽  
Control Activity ◽  
Significant Difference ◽  
Cucumber Roots ◽  
Linear Regressions

Nonpathogenic isolates of Fusarium oxysporum were obtained from surface-disinfested, symptomless cucumber roots grown in two raw (nonautoclaved) soils. These isolates were screened for pathogenicity and biological control activity against Fusarium wilt of cucumber in raw soil infested with Fusarium oxysporum f. sp. cucumerinum (F.o.c.). The influence of three isolates effective in inducing suppressiveness and three ineffective isolates on disease incidence over time was tested. The effective isolates reduced the infection rate (R), based on linear regressions of data transformed to loge (1/1 – y). Effective isolate C5 was added to raw soil infested with various inoculum densities of F.o.c. In treatments without C5, the increase in inoculum densities of F.o.c. decreased the incubation period of wilt disease, but there was no significant difference in infection rate among the inoculum density treatments. Isolate C5 reduced the infection rate at all inoculum densities of F.o.c. Various inoculum densities of C5 were added to raw soils infested with 1000 cfu/g of F.o.c. In the first trial, infection rates were reduced only in the treatment with 10 000 cfu/g of C5; in the second trial, infection rates were reduced in treatments with 10 000 and 30 000 cfu/g of C5.

The in vitro inhibition of Phytophthora clandestina by some rhizobia and the possible role of Rhizobium trifolii in biological control of Phytophthora root rot of subterranean clover

1999 ◽  
Vol 50 (8) ◽  
pp. 1469 ◽  
Author(s):  
S. Simpfendorfer ◽  
T. J. Harden ◽  
G. M. Murray
Keyword(s):  
Biological Control ◽  
Root Rot ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Root Disease ◽  
Rhizobium Trifolii ◽  
Biological Control Agents ◽  
Control Activity ◽  
Phytophthora Root Rot

The interaction between 29 isolates of Rhizobium and the in vitro growth of 3 strains of Phytophthora clandestina was investigated to determine the potential of these bacteria as biological control agents against root rot of subterranean clover (Trifolium subterraneum L.). The biological control activity of Rhizobium on the severity of root disease in seedlings was also investigated under glasshouse conditions. Thirteen of the 29 Rhizobium isolates caused significant reductions in the hyphal growth of the 3 P. clandestina isolates examined. Inoculation of seedlings with Rhizobium trifolii reduced the severity of root disease by 14–58% with corresponding increases in dry matter production of 20–73%. These results indicate that Rhizobium species have potential as biological control agents against the root rot of T. subterraneum seedlings caused by P. clandestina.

scholarly journals The Iturin-like Lipopeptides Are Essential Components in the Biological Control Arsenal of Bacillus subtilis Against Bacterial Diseases of Cucurbits

2011 ◽  
Vol 24 (12) ◽  
pp. 1540-1552 ◽  
Author(s):  
Houda Zeriouh ◽  
Diego Romero ◽  
Laura García-Gutiérrez ◽  
Francisco M. Cazorla ◽  
Antonio de Vicente ◽  
...  
Keyword(s):  
Biological Control ◽  
Antibacterial Activity ◽  
Bacillus Subtilis ◽  
Xanthomonas Campestris ◽  
Soft Rot ◽  
Bacterial Diseases ◽  
Chromatography Analysis ◽  
Essential Components ◽  
Bacillus Spp

The antibacterial potential of four strains of Bacillus subtilis, UMAF6614, UMAF6619, UMAF6639, and UMAF8561, previously selected on the basis of their antifungal activity and efficacy against cucurbit powdery mildew, was examined. Among these strains, UMAF6614 and UMAF6639 showed the highest antibacterial activity in vitro, especially against Xanthomonas campestris pv. cucurbitae and Pectobacterium carotovorum subsp. carotovorum. These strains produced the three families of lipopeptide antibiotics known in Bacillus spp.: surfactins, iturins, and fengycins. Using thin-layer chromatography analysis and direct bioautography, the antibacterial activity could be associated with iturin lipopeptides. This result was confirmed by mutagenesis analysis using lipopeptide-defective mutants. The antibacterial activity was practically abolished in iturin-deficient mutants, whereas the fengycin mutants retained certain inhibitory capabilities. Analyses by fluorescence and transmission electron microscopy revealed the cytotoxic effect of these compounds at the bacterial plasma membrane level. Finally, biological control assays on detached melon leaves demonstrated the ability of UMAF6614 and UMAF6639 to suppress bacterial leaf spot and soft rot; accordingly, the biocontrol activity was practically abolished in mutants deficient in iturin biosynthesis. Taken together, our results highlight the potential of these B. subtilis strains as biocontrol agents against fungal and bacterial diseases of cucurbits and the versatility of iturins as antifungal and antibacterial compounds.

scholarly journals Antagonisme Bacillus terhadap Infeksi Layu Fusarium pada Bibit Pisang Hasil Kultur Jaringan

2013 ◽  
Vol 15 (1) ◽  
pp. 21
Author(s):  
Hadiwiyono Hadiwiyono ◽  
Arief Widyantoro ◽  
Salim Widono
Keyword(s):  
Biological Control ◽  
Fusarium Oxysporum ◽  
Fusarium Wilt ◽  
In Planta ◽  
Physiological Character ◽  
Important Disease

<p>Fusarium wilt (Fusarium oxysporum f.sp. cubense) is an important disease in banana. Fusarium wilt was hard to control because the pathogen can survive in many kind of soils type although there is no host. Therefore, overcoming the disease is urgently needed such as biological control. The endophytic Bacillus of banana was begun to use as antagonist agent to the pathogen. This research aimed to study the mechanism of antagonism and physiological character of Bacillus. There were 27 Bacillus isolates examined in-vitro to test the production of IAA, HCN, chitinase, pectinase, and antagonism. The top ten isolates based on the test in vitro were used to test in planta. The research showed that Bacillus were able to produce IAA, HCN, chitinase, pectinase, and able to retard the growth of Foc colony. The application of isolat B25 on banana seedling could decrease the disease intensity but still unable to prevent the fusarium wilt infection.</p>

scholarly journals BIOLOGICAL CONTROL OF Colletotrichum gloeosporioides IN PEPPER WITH ISOLATES OF Bacillus subtilis

2018 ◽  
Vol 93 (2) ◽  
pp. 195
Author(s):  
Jeniffer Kelly Cortes Amaro ◽  
Bruno Sérgio Vieira ◽  
Luciana Alves Sousa
Keyword(s):  
Biological Control ◽  
Bacillus Subtilis ◽  
Colletotrichum Gloeosporioides

Objetivou-se estudar o potencial antagônico de isolados de Bacillus subtilis a Colletotrichum gloeosporioides, agente causal da antracnose em frutos de pimenta. Foram estudados 21 isolados de Bacillus subtilis quanto a capacidade de inibir o desenvolvimento do fitopatógeno nas seguintes metodologias in vitro: cultivo pareado, metabólitos produzidos pelos isolados, influência da inoculação conjunta e controle da antracnose in vivo (frutos destacados de pimenta). Os isolados BSV-11, BSV-05, BSV-12, BSV-17, BSV-07, BSV-16, BSV-09, BSV-20, BSV-13 e BSV-18 foram promissores como potenciais antagonistas a C. gloeosporioides, com evidente formação de halo de inibição, para a metodologia do cultivo pareado. Estes isolados produziram metabólitos termoestáveis contra C. gloeosporioides evidenciando ser antibiose o mecanismo antagônico envolvido na supressão do patógeno. O contato direto dos isolados bacterianos com o patógeno inibiu totalmente o crescimento micelial de C. gloeosporioides, exceto os isolados BSV-20 e BSV-09. Os isolados BSV-20, BSV-18, BSV-17, BSV-07 e BSV-12 inibiram significativamente infecções de antracnose em frutos de pimenta em pós-colheita.

scholarly journals Hongos causantes de enfermedades postcosecha en chayote (Sechium edule(Jacq.) SW.) y su control in vitro

2015 ◽  
Author(s):  
Siul D. Romero Velazquez ◽  
Bertha Tlapal Bolaños ◽  
Jorge Cadena Iñiguez ◽  
Daniel Nieto Ángel ◽  
María de Lourdes Arévalo Galarza
Keyword(s):  
Bacillus Subtilis ◽  
Costa Rica ◽  
Fusarium Oxysporum ◽  
Chaetomium Globosum ◽  
Didymella Bryoniae ◽  
Chain Reaction ◽  
Sechium Edule

El fruto de chayote (Sechium edule (Jaqc.) Sw.) es una hortaliza de exportación de importancia para México y Costa Rica. El proceso comercial exige cumplir con estándares de calidad, que implican frutos sanos y libres de defectos. Sin embargo, debido a las condiciones de alta humedad que se desarrollan en los frutos empacados en películas plásticas, se han presentado rechazos en el mercado de exportación, por la presencia de enfermedades fungosas. El objetivo de este trabajo fue identificar morfológica (microscopía óptica y electrónica de barrido) y molecularmente (PCR: Polimerase Chain Reaction) las especies de hongos causales de las principales enfermedades postcosecha de chayote en frutos infectados procedentes de huertas comerciales para exportación, así como probar in vitro la efectividad de diversos productos comerciales en la inhibición del crecimiento de dichos hongos. Los resultados mostraron a Didymella bryoniae como el causante de “gomosis de las cucurbitáceas” y a Fusarium oxysporum y F. solani como causales de fusariosis o ahogamiento de guías; estos patógenos dañan la parte basal y media de frutos comerciales, además de Chaetomium globosum, un asociado al proceso infeccioso de Fusariumsp., como saprófito no patógeno. La inoculación con Bacillus subtilis presentó una inhibición efectiva (0,01 mg.l-1 i.a) en las pruebas in vitro contra Didymella bryoniae, Fusarium oxysporum y F. solani; el fungicida más efectivo contra los 2 primeros fue Tebuconazole-trifloxystrobin, con una DL50 de 0,0116 y 0,0106 mg.l-1 respectivamente; no así contra F. solani, cuyo mayor control fue registrado con procloraz, con DL50 de 0,0042 mg.l-1. Estos resultados contribuyen al reconocimiento de las enfermedades fungosas más importantes en chayote y su perspectiva de control durante el manejo postcosecha de frutos para exportación.

scholarly journals Isolation, Identification and In Vitro Test for the Biocontrol Potential of Trichoderma viride on Fusarium oxysporum f. sp. Lycopersici

2021 ◽  
Vol 15 (1) ◽  
pp. 10-20
Author(s):  
Tsegaye Mekuria Ayele ◽  
Guesh Desta Gebremariam ◽  
Subban Patharajan
Keyword(s):  
Fusarium Oxysporum ◽  
Trichoderma Viride ◽  
Dual Culture ◽  
In Vitro Test ◽  
Tomato Production ◽  
Biocontrol Efficacy ◽  
Pests And Diseases ◽  
Dual Culture Assay ◽  
Biocontrol Potential

Introduction: Tomato production in Ethiopia is challenged by many pests and diseases. Fusarium wilt is one of the most important diseases of tomato affecting its productivity. Methods: Tomato tissue and soil samples were collected from tomato farmlands around Aksum town to isolate and identify pathogenic Fusarium species and Trichoderma species with biocontrol efficacy. Samples were processed in the Aksum University Biotechnology laboratory following standard procedures. Results and Discussion: Eight Fusarium and five Trichoderma isolates were obtained. Six of the Fusarium isolates were identified as Fusarium oxysporum, whereas the remaining two were Fusarium equiseti and Fusarium circinatum. Detached leaf bioassay of the F. oxysporum on tomato leaves showed leaf lesion on the tomato variety, Melka oda. The isolated Trichoderma strains were screened for biocontrol potential against virulent F. oxysporum in vitro. The Trichoderma isolate showing the highest biocontrol efficacy against the virulent Fusarium was morphologically identified as Trichoderma viride. in vitro F. oxysporum-T. viride dual culture assay demonstrated that T. viride inhibits the growth of F. oxysporum f.sp. lycopersici with 76.94% growth inhibition. Conclusion: Fusarium oxysporum is prevalent in tomato growing farmlands covered in this study. T. viride identified in this study is an effective biocontrol agent for the identified F. oxysporum fsp. lycopersici in vitro.

scholarly journals Cladobotryum mycophilum as Potential Biocontrol Agent

Agronomy ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 891
Author(s):  
Mila Santos ◽  
Fernando Diánez ◽  
Alejandro Moreno-Gavíra ◽  
Brenda Sánchez-Montesinos ◽  
Francisco J. Gea
Keyword(s):  
Biological Control ◽  
Fusarium Oxysporum ◽  
Biocontrol Agent ◽  
Biological Control Agent ◽  
Control Agent ◽  
Phytopathogenic Fungi ◽  
Antagonistic Activity ◽  
Dual Culture ◽  
Potential Biocontrol Agent

A study was conducted to explore the efficacy of potential biocontrol agent Cladobotryum mycophilum against different phytopathogenic fungi. The growth rates of 24 isolates of C. mycophilum were determined, and their antagonistic activity was analysed in vitro and in vivo against Botrytis cinerea, Fusarium oxysporum f. sp. radicis-lycopersici, Fusarium oxysporum f.sp. cucumerinum, Fusarium solani, Phytophthora parasitica, Phytophthora capsici, Pythium aphanidermatum and Mycosphaerella melonis. Most isolates grow rapidly, reaching the opposite end of the Petri dish within 72–96 h. Under dual-culture assays, C. mycophilum showed antagonistic activity in vitro against all phytopathogenic fungi tested, with mycelial growth inhibition ranging from 30 to 90% against all the different phytopathogens tested. Similarly, of all the selected isolates, CL60A, CL17A and CL18A significantly (p < 0.05) reduced the disease incidence and severity in the plant assays compared to the controls for the different pathosystems studied. Based on these results, we conclude that C. mycophilum can be considered as a potential biological control agent in agriculture. This is the first study of Cladobotryum mycophilum as a biological control agent for different diseases caused by highly relevant phytopathogens in horticulture.

scholarly journals POTENCIAL ANTAGONÍSTICO DO ISOLADO BACTERIANO (BSV- 05) CONTRA OS PATÓGENOS RADICULARES DO FEIJOEIRO: Fusarium solani f. sp. phaseoli, Fusarium oxysporum f. sp. phaseoli, Macrophomina phaseolina e Rhizoctonia solani

2017 ◽  
Vol 14 (1) ◽  
pp. 59 ◽  
Author(s):  
Bruno Sérgio Vieira ◽  
Hyann Markos Pereira Vieira ◽  
Luciana Alves de Sousa ◽  
Karoline Damasceno Ribeiro de Mendonça
Keyword(s):  
Bacillus Subtilis ◽  
Rhizoctonia Solani ◽  
Fusarium Oxysporum ◽  
Fusarium Solani ◽  
Macrophomina Phaseolina ◽  
E 92

<p>Durante uma seleção de bactérias antagonistas realizada no Laboratório de Microbiologia e Fitopatologia da UFU, o isolado de <em>Bacillus subtilis</em>, BSV – 05 se destacou. Diante disso, objetivou-se no presente trabalho avaliar o potencial antagonístico <em>in vitro</em> deste isolado bacteriano contra quatro patógenos radiculares do feijoeiro: <em>Fusarium solani </em>f. sp. <em>phaseoli, Fusarium oxysporum</em> f. sp. <em>phaseoli, Macrophomina phaseolina </em>e <em>Rhizoctonia solani</em>. Foram utilizadas as seguintes metodologias <em>in vitro </em>versus os patógenos citados:<em> </em>cultivo pareado, influência da inoculação conjunta, produção de metabolitos voláteis e não voláteis. Os percentuais de inibição do isolado BSV – 05 sobre <em>M. phaseolina, R. solani, F. solani,</em> <em>F. oxysporum</em>, foram de 61,43%; 50,36%; 13,74% e 7,7%, respectivamente, para a metodologia do cultivo pareado. O contato direto da bactéria com os patógenos inibiu em 100% o crescimento micelial de <em>M. phaseolina, R. solani</em>; e para <em>F. solani </em>e <em>F. oxysporum</em>, foram observadas inibições de 90 e 92 %, respectivamente. Possíveis metabólitos secretados pelo isolado BSV 05 apresentaram níveis de inibição de 100% para <em>R. solani</em>. Para <em>M. phaseolina</em>, observou-se uma porcentagem de inibição de 80,26%, e 45,31% e 47,80% para <em>F. solani </em>e <em>F. oxysporum</em>, respectivamente. A porcentagem de inibição da germinação de conídios de <em>F. solani </em>e <em>F. oxysporum </em>e<em> M. phaseolina</em> num meio de cultura contendo substâncias metabolizadas por BSV – 05 foi de 87,70; 91,28% e 100%, respectivamente. O isolado bacteriano BSV-05 não apresentou produzir nenhum metabólito volátil.</p>

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