scholarly journals Đánh giá khả năng đối kháng của các chủng Trichoderma spp. và Bacillus subtilis đối với chủng Pythium vexans gây bệnh chết nhanh trên hồ tiêu

2020 ◽  
Vol 13 (1) ◽  
pp. 168-179
Author(s):  
Nguyễn Thị Ánh Nguyệt ◽  
Lê Thị Mai Châm ◽  
Trần Thùy Trang ◽  
Dương Hoa Xô
Keyword(s):  
Bacillus Subtilis ◽  
Trichoderma Spp ◽  
Pythium Vexans ◽  
Bacillus Spp

Pythium spp. được biết đến là một trong những tác nhân chính gây bệnh chết nhanh dẫn đến thiệt hại nặng nề về năng suất cây hồ tiêu (Shashidhara, 2007). Có nhiều biện pháp đã được áp dụng để phòng trừ bệnh chết nhanh trên hồ tiêu như hóa học, sinh học… Tuy nhiên, việc sử dụng thuốc hóa học thường cho hiệu quả thấp, độc hại và gây ô nhiễm môi trường nên biện pháp sinh học đang được chú trọng nhờ hiệu quả lâu dài và thân thiện với môi trường. Trong đó, Trichoderma spp. và Bacillus spp. từ lâu đã được chứng minh có khả năng đối kháng tốt với nấm Pythium spp. nhờ tiết một số loại enzyme ngoại bào như glucanase, chitinase, cellulose… (Anita Patil và cộng sự 2012; Amrita và cộng sự, 2016; Najwa Benfradj và cộng sự, 2016). Nghiên cứu này cho thấy rằng, trong điều kiện in vitro, ở nồng độ 106 bào tử động/ml, chủng Pythium vexans P6 có khả năng gây bệnh thối nhanh rễ tiêu với chỉ số gây hại và tỉ lệ hại cao nhất trong 11 chủng Pythium vexans. Ngoài ra, các kết quả thu được đã chứng minh 12 chủng Trichoderma spp. và 5 chủng Bacillus subtilis có khả năng đối kháng với chủng Pythium vexans P6 trong phòng thí nghiệm. Sau 6 ngày đồng nuôi cấy, phần trăm ức chế nấm bệnh của các chủng Trichoderma spp. đạt từ 40-90%. Sau 8 ngày, hầu hết khuẩn lạc các chủng Trichoderma spp. đã ức chế hoàn toàn nấm bệnh. Bên cạnh đó, cả 5 chủng Bacillus subtilis đều có khả năng đối kháng với chủng nấm bệnh Pythium vexans P6. Tuy nhiên, tỷ lệ ức chế nấm bệnh của các chủng Bacillus subtilis chỉ đạt từ 22,69-27,67% sau 6 ngày đồng nuôi cấy, thấp hơn so với các chủng Trichoderma spp..

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 Biological Efficacy of Trichoderma spp. and Bacillus spp. in the Management of Plant Diseases

2020 ◽  
Author(s):  
Francisco Daniel Hernández-Castillo ◽  
Francisco Castillo-Reyes ◽  
Marco Antonio Tucuch-Pérez ◽  
Roberto Arredondo-Valdes
Keyword(s):  
Biological Control ◽  
Fruit Trees ◽  
Plant Diseases ◽  
In Vitro Tests ◽  
Taxonomic Identification ◽  
Trichoderma Spp ◽  
Antifungal Effect ◽  
Bacillus Spp ◽  
Microbial Strain

This chapter will cover topics about the microbial antagonists Trichoderma spp. and Bacillus spp. from the perspective of use as potential biological control agents on plant diseases. Results obtained in the laboratory about from their isolation, microbial strain collections for both genera, taxonomic identification, antifungal activity in in vitro tests, obtained evaluation of the antifungal effect of secondary metabolites from microbial antagonists will be shown. Besides, results obtained from bioassays in the greenhouse and field are used as biopesticides in the control of diseases in fruit trees and vegetables and their effects on the promotion of plant growth and increased crop yield.

scholarly journals Identification and antagonistic activity in vitro of Bacillus spp. and Trichoderma spp. isolates against common phytopathogenic fungi

2015 ◽  
Author(s):  
Claudio Rios-Velsaco ◽  
Janeth Caro-Cisneros ◽  
David Berlanga-Reyes ◽  
Maria Fernanda Ruíz-Cisneros ◽  
José Ornelas-Paz ◽  
...  
Keyword(s):  
Aspergillus Nidulans ◽  
Phytopathogenic Fungi ◽  
Antagonistic Activity ◽  
Trichoderma Spp ◽  
Penicillium Crustosum ◽  
Bacillus Spp

Muchas enfermedades en cultivos causadas por hongos patógenos representan un problema económico debido a las pérdidas que éstas causan. Del mismo modo microorganismos antagonistas tales como <em>Trichoderma</em> spp. y <em>Bacillus</em> spp., entre otros, han sido usados como agentes de control biológico como una alternativa eficiente para reducir el uso de fungicidas químicos en el control de enfermedades de plantas. El objetivo de este estudio fue identificar taxas de microorganismos patógenos y antagonistas basado en sus caracteres moleculares y evaluar la actividad antagónica <em>in vitro</em> de dos aislados de <em>Bacillus</em> y dos aislados de <em>Trichoderma</em> contra cinco hongos patogénicos comunes: <em>Fusarium</em> <em>oxysporum</em>, <em>Botrytis</em> <em>cinerea</em>,<em> Penicillium crustosum</em>,<em> Aspergillus nidulans</em> y <em>Alternaria</em> <em>alternata</em>. Para la identificación molecular, los nueve microorganismos fueron usados para la extracción del ADN genómico y amplificación del gen del ADN ribosomal 18S y del Espaciador Transcrito Interno con los iniciadores ITS  (ITS5 e ITS4) para los hongos y el gen del 16S del ADNr, usando los iniciadores universales EU(F) y EU(R) para bacterias. Ambos aislados de <em>T. asperellum</em> mostraron una actividad antagonista significativa contra los hongos fitopatógenos probados, donde los porcentajes de inhibición del crecimiento radial (PICR) de las colonias de hongos fitopatógenos fluctuó de 43 a 71%, mientras los PICR inducidos por <em>Bacillus</em> fueron significativos, con valores de hasta 69% cuando se probaron <em>in vitro</em> contra <em>B. cinerea</em>, mientras que el efecto más bajo se observó con <em>F. oxysporum</em>, <em>P. crustosum</em> y <em>A. nidulans</em>. Ambas especies de <em>Bacillus</em>, indujeron la presencia de un halo de inhibición, con valores de 5 y 11 mm, cuando se probaron <em>in vitro</em> contra <em>F. oxysporum</em> y <em>B. cinerea</em>, respectivamente. Los efectos antagonistas de los aislados de bacterias y hongos, muestran que estos microorganismos pueden ser usados como agentes de control biológico de varios hongos fitopatógenos de cultivos.

scholarly journals Diversity of Nematode Microbial Antagonists from Algeria Shows Occurrence of Nematotoxic Trichoderma spp.

Plants ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 941
Author(s):  
Nawal Benttoumi ◽  
Mariantonietta Colagiero ◽  
Samira Sellami ◽  
Houda Boureghda ◽  
Abdelaziz Keddad ◽  
...  
Keyword(s):  
Pcr Amplification ◽  
16S Rrna Gene Sequencing ◽  
Rrna Gene ◽  
Fusarium Spp ◽  
Trichoderma Spp ◽  
Bacillus Spp ◽  
Phytoparasitic Nematodes ◽  
Meloidogyne Spp ◽  
Rrna Gene Sequencing

Fungi and bacteria associated to phytoparasitic nematodes Globodera rostochiensis and Meloidogyne spp. in Algeria were identified and characterized. Trichoderma spp. showed the highest prevalence in the cysts of G. rostochiensis. A number of isolates were identified through PCR amplification and the sequencing of the internal transcribed spacer (ITS)1-2 and Rpb2 gene regions. The most represented species were T. harzianum and T. afroharzianum. The latter and T. hirsutum were reported for the first time in Algeria. Fusarium spp., including F. oxysporum and F. solani, comprised a second group of fungi found in cysts. Taxa associated to females of Meloidogyne spp. included T. harzianum, Fusarium spp. and other hyphomycetes. To assess the efficacy of Trichoderma spp., two assays were carried out in vitro with the culture filtrates of two T. afroharzianum and T. harzianum isolates, to check their toxicity versus the second stage juveniles of M. incognita. After 24–48 h exposure, a mortality significantly higher than the control was observed for both filtrates at 1% dilutions. The TRI genes involved in the production of trichothecenes were also amplified with the PCR from some Trichoderma spp. isolates and sequenced, supporting a putative role in nematode toxicity. Bacteria isolated from the cysts of G. rostochiensis included Brucella, Rhizobium, Stenotrophomonas and Bacillus spp., identified through 16S rRNA gene sequencing. The potential of the microbial isolates identified and their mechanisms of action are discussed, as part of a sustainable nematode management strategy.

scholarly journals Isolate Neoscytalidium dimidiatum fungal pathogens from pytaya (Hylocereus undatus) and research controlling by microorganisms

2020 ◽  
Vol 3 (4) ◽  
pp. 286-293
Author(s):  
Nhut Nhu Nguyen ◽  
Nguyen Thi Ngoc Bich ◽  
Nguyen Thanh Truong ◽  
Vo Thi Xuyen
Keyword(s):  
Agar Medium ◽  
Antagonistic Effect ◽  
Dual Culture ◽  
Trichoderma Spp ◽  
Neoscytalidium Dimidiatum ◽  
Streptomyces Spp ◽  
Trichoderma Sp ◽  
Bacillus Spp

In recent years, Neoscytalidium dimidiatum has caused severe white spot disease in Pytaya, while no effective controls have been taken. In this study, two strains of N. dimidiatum NdGV and NdBT were obtained by isolation on water agar medium containing streptomycin, morphological tests, in vitro and in vivo pathogenical tests, and molecular biology tests by sequencing the genes ITS1 and ITS4. By using dual culture technique on potato-glucose agar medium, 100% of Trichoderma spp., 75% of Bacillus spp. and 20% of Streptomyces spp. were able to antagonize N. dimidiatum. The mean antagonistic effect with N. dimidiatum of Trichoderma spp. was higher than Bacillus spp. and the lowest was Streptomyces spp. 56.8%, 55.3% and 54.3% respectively. Especially 5 strains Trichoderma sp. 8.3.5, 8.3.7, 8.3.14, 8.3.19, and 8.3.20 had antagonistic effects of over 60%. The application potential of the 5 selected Trichoderma strains to control N. dimidiatum disease was further strengthened when their antagonistic effect was relatively stable on Pitaya juice agar medium while all Bacillus sp. and Streptomyces sp. were lost the ability to antagonize. It was noteworthy that four of the five strains of Trichoderma sp. were highly compatible, suggesting further studies are needed to apply their combined potency in enhancing the control of N. dimidiatum NdBT and NdGV on Pitaya.  

scholarly journals Controle biológico da mancha-aquosa do melão por compostos bioativos produzidos por Bacillus spp.

2006 ◽  
Vol 32 (4) ◽  
pp. 376-378 ◽  
Author(s):  
Elizama Roza Santos ◽  
Ester Ribeiro Gouveia ◽  
Rosa Lima Ramos Mariano ◽  
Ana Maria Souto-Maior
Keyword(s):  
Bacillus Subtilis ◽  
Bacillus Sp ◽  
Bacillus Spp

A mancha-aquosa, causada por Acidovorax avenae subsp. citrulli (Aac) causa grandes prejuízos à cultura do melão. O controle dessa doença foi estudado in vivo, com microbiolização de sementes de melão Amarelo infectadas, com líquidos fermentados de Bacillus subtilis R14, B. megaterium pv. cerealis RAB7, B. pumilus C116 e Bacillus sp. MEN2, com e sem células bacterianas. O mecanismo de ação dos isolados foi estudado in vitro pelo método de difusão em ágar e os compostos bioativos parcialmente caracterizados por testes de hemólise e atividade surfactante. Nos testes in vivo, não houve diferença significativa entre os tratamentos com e sem células, indicando que o controle ocorreu devido à presença de compostos bioativos produzidos durante as fermentações. Todos os tratamentos diferiram da testemunha sem diferir entre si (P=0,05%). B. megaterium pv. cerealis RAB7 proporcionou redução da incidência (89,1%) e do índice de doença (92,7%), elevou o período de incubação da mancha-aquosa de 9,8 para 11,9 dias e reduziu a AACPD de 3,36 para 0,17. In vitro, todos isolados apresentaram antibiose contra Aac e os compostos bioativos foram parcialmente caracterizados como lipopeptídeos.

scholarly journals Evaluación del efecto biocontrolador de Bacillus spp., frente a Fusarium spp., bajo condiciones de invernadero en Rosmarinus officinalis L

Nova ◽  
2010 ◽  
Vol 8 (13) ◽  
pp. 63
Author(s):  
Diana Bautista ◽  
Lucía Constanza Corrales Ramírez MSC ◽  
Jairo Leonardo Cuervo Andrade PhD ◽  
Lady González ◽  
Marcela Guevara ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Bacillus Megaterium ◽  
Rosmarinus Officinalis ◽  
Fusarium Spp ◽  
Bacillus Brevis ◽  
Fusarium Acuminatum ◽  
Bacillus Spp ◽  
Rosmarinus Officinalis L

El romero es una de las plantas aromáticas más importantes dentro del mercado de exportación  colombiano. El cultivo de esta planta se ve afectado por marchitez vascular producida por <em>Fusarium </em>spp. El objetivo principal de este trabajo fue establecer en el romero el efecto biocontrolador de <em>Bacillus </em>spp., frente a <em>Fusarium </em>spp., bajo condiciones de invernadero. Para ello se seleccionaron <em>Bacillus liqueniformis </em>(B1<em>), Bacillus subtilis </em>(B2), <em>Bacillus megaterium </em>(B14), <em>Bacillus brevis </em>(E2), aislados de rizósfera de plantas aromáticas, a los cuales se les realizaron pruebas de viabilidad, identificación enzimática manual y automatizada, y pruebas de antagonismo <em>in vitro </em>en medio PDA frente a <em>Fusarium acuminatum </em>aislado de las plantas de romero, comprobando la patogenicidad del hongo por postulados de Koch.<p>El ensayo se realizó con 30 plántulas de romero, un control negativo y uno positivo, bioensayos con sólo <em>Bacillus </em>spp., y tratamientos con <em>Bacillus </em>spp., más el patógeno. Para evaluar la severidad del patógeno y el comportamiento de las bacterias cada ensayo se realizó por triplicado y bajo condiciones de invernadero. En las pruebas de antagonismo <em>in vitro </em>B1 y B2 presentaron entre el 70–100% de inhibición del micelio y B14 y E2 entre el 40–69%. Los <em>Bacillus </em>spp<em>., </em>disminuyeron la severidad de la marchitez vascular en todos los ensayos; por la producción de sustancias antifúngicas facilitaron el aumento del peso seco de las hojas de las plantas al permitir la obtención de nutrientes y B14 aumentó la longitud de la raíz y el tallo. Se precisa secuenciar el aislamiento de <em>Fusarium, </em>para confirmar la especie.</p>

scholarly journals CONTROLE BIOLÓGICO DE Bursaphelenchus cocophilus POR RIZOBACTÉRIAS E Trichoderma spp.

Nativa ◽  
2018 ◽  
Vol 6 (3) ◽  
pp. 233
Author(s):  
Carina Melo da Silva ◽  
Cássia Cristina Chaves Pinheiro ◽  
Ieda Alana Leite de Sousa ◽  
Paulo Manoel Ponte Lins ◽  
Gisele Barata da Silva ◽  
...  
Keyword(s):  
Biological Control ◽  
Mortality Rate ◽  
Trichoderma Spp ◽  
Pseudomonas Spp ◽  
Phosphate Solubilizers ◽  
Pathogenesis Related ◽  
Bacillus Spp ◽  
Nematode Mortality

O objetivo do trabalho foi avaliar o potencial de rizobactérias e Trichoderma spp. no controle biológico de Bursaphelenchus cocophilus. Foram avaliados 19 isolados de Pseudomonas spp. (P), 29 de Bacillus spp. (B) e 27 de Trichoderma spp. (T), obtidos de plantio comercial. Os isolados foram caracterizados quanto a produção de compostos bioquímicos. Foi avaliada a taxa de mortalidade de B. cocophilus in vitro e in vivo, neste último realizou-se também a quantificação das enzimas relacionadas à patogênese. Os isolados B14 e P41 proporcionaram 69% e 56% de taxa de mortalidade de nematoides, respectivamente e foram tanto proteolíticos como solubilizadores de fosfato. Os isolados T41 e T54 apresentaram 96% de mortalidade de B. cocophilus in vitro e foram produtores de quitinases, protease e sideróforos. No experimento in vivo, os isolados de rizobactérias B14, B23 e P23 promoveram maior taxa de mortalidade do B. cocophilus do que os demais tratamentos. As mudas de coqueiro inoculadas com o B. cocophilus apresentaram aumento nas atividades das enzimas peroxidases, quitinase e β-1,3-glucanases, quando comparadas com a testemunha (mudas não inoculadas). Os isolados B41, P14, T41 e T54 apresentaram-se como potenciais agentes de controle biológico do B. cocophilus.Palavras-chave: anel vermelho, antagonismo, nematoid. BIOLOGIC CONTROL OF Bursaphelenchus cocophilus WITH RHIZOBACTERIA AND Trichoderma isolates  ABSTRACT:The purpose of this study was to evaluate the potential of rhizobacteria Pseudomonas spp. and Bacillus spp. and Trichoderma spp. isolates on the biological control of the nematode Bursaphelenchus cocophilus. The potential biological control isolates (48 rhizobacteria and 27 Trichoderma spp.) were characterized biochemically. The biological control experiments were carried out "in vitro" and "in vivo", and in the later one, the mortality rate of the nematodes and the pathogenesis related enzymes were evaluated. Rhizobacterial isolates B14 and P41 provided a high nematode mortality rate (69% and 56%, respectively) and both were proteolytic and phosphate solubilizers. In the "in vivo" experiment, rhizobacterial isolates B14, B23 and P23 tested the highest mortality rates of B. cocophilus than the isolates of Trichoderma spp. and of the control as coconut saplings challenged with B. cocophilus showed indices higher in enzyme activities, peroxidases, chitinase and β-1,3-glucanases when compared to witness (seedling not inoculated). The isolates B41, P14, T41 and T54 were presented as potential biological control agents of B. cocophilus.Keywords: red ring, antagonism, nematode. DOI:   

scholarly journals Biocontrollers in the management of yam dry rot nematodes

2021 ◽  
Vol 6 (1) ◽  
pp. 24-35
Author(s):  
Cecilia Ramirez ◽  
Alverlan da Silva Araújo ◽  
Gilson Moura Filho ◽  
Fernando da Silva Rocha ◽  
Marylia Gabriella Silva Costa ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Organic Carbon ◽  
Nematode Population ◽  
In Vitro Assays ◽  
Population Densities ◽  
Dry Rot ◽  
Seed Tubers ◽  
Bacillus Spp

ABSTRACT: One of the main diseases affecting yam crops (Dioscorea spp.) in Brazil is the dry rot caused by Scutellonema bradys, Pratylenchus brachyurus and P. coffeae nematodes. The use of biological control agents is an auspicious procedure which has been tested in order to reduce losses by pathogens. The objective of this work was to evaluate the nematicidal activity in vitro and in vivo of commercial biological products on yam dry rot nematodes. Products based on Trichoderma harzianum (2.0 x 109 conidia mL-1) at dosages of 1.5 and 2.0 L 200 L-1 of water; Bacillus subtilis 20% - 1.0 x 1011 cfu g-1 + B. licheniformis 20% - 1.0 x 1011 cfu g-1 at 100 and 150 g 100 L-1; B. subtilis 200 g kg-1 + B. licheniformis 200 g kg-1 at 130 and 200 g 100 L-1; combination of rhizobacteria including Bacillus spp. and organic carbon at 5L and 7L 100 L-1; and the control (distilled water), were tested in in vitro assays on S. bradys or Pratylenchus sp. In experiments performed under greenhouse conditions, healthy seed tubers were planted in sterilized soil and thirty days later the soil was infested with a suspension of 1,000 specimens of a mixed population of S. bradys and P. coffeae. Then, after 30 days products based on B. subtilis 20% + B. licheniformis 20% - 150 g 100 L-1; T. harzianum 2 L 200 L-1 and rhizobacteria + organic carbon 7 L 100 L-1, at 100 mL per pot, were applied to the soil. Three months after planting, the percentage of sprouting of the seed tubers was evaluated and in the fifth month, the nematode population densities were determined. The sprouting of seed tubers was of 100% in all treatments. Bacillus subtilis 20% + B. licheniformis 20% and T. harzianum caused 89% and 61% mortality in S. bradys respectively, at the highest concentrations. In specimens of Pratylenchus sp., rhizobacteria + organic carbon exhibited 51% and 45% mortality at higher and lower concentrations, respectively. Under greenhouse conditions, B. subtilis 20% + B. licheniformis 20% and rhizobacteria + organic carbon were more effective in reducing nematode population densities, compared to the control. KEYWORDS: Dioscorea spp.; Scutellonema bradys; Pratylenchus sp.

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