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 Biological Control of Ceratocystis fimbriata by Bacillus subtilis on Acacia mearnsii Seedlings

2019 ◽  
Vol 26 (4) ◽  
Author(s):  
Ricardo Mezzomo ◽  
Graziela Piveta ◽  
Marília Lazarotto ◽  
Clair Walker ◽  
Caciara Gonzatto Maciel ◽  
...  
Keyword(s):  
Biological Control ◽  
Bacillus Subtilis ◽  
Acacia Mearnsii ◽  
Ceratocystis Fimbriata ◽  
Before And After ◽  
Pathogenicity Tests ◽  
Antagonistic Potential ◽  
Black Wattle

ABSTRACT The aim of this study was to evaluate the effect of Ceratocystis fimbriata isolates, obtained from Actinidia deliciosa (kiwifruit), on black wattle (Acacia mearnsii De Wild.) seedlings, the potential biological control exerted in vitro by Bacillus subtilis on C. fimbriata, and the in vivo effect of B. subtilis against C. fimbriata on black wattle seedlings. Isolates of C. fimbriata obtained and identified from kiwi plantations were used in pathogenicity tests on A. mearnsii seedlings. In vitro, the antagonistic potential of B. subtilis on the pathogen was analyzed by direct confrontation tests. To evaluate the effect of B. subtilis in vivo, black wattle seedlings were inoculated with Rhizolyptus® seven days before and after pathogen inoculation. On black wattle seedlings, C. fimbriata isolates caused 44,15% to 100% severity. Direct confrontation tests revealed that the strains were effective in the biological control of C. fimbriata isolates in vitro. In vivo, Rizolyptus® was not efficient in controlling C. fimbriata.

scholarly journals In Bacillus subtilis, the Sirtuin Protein Deacetylase, Encoded by the srtN Gene (Formerly yhdZ), and Functions Encoded by the acuABC Genes Control the Activity of Acetyl Coenzyme A Synthetase

2009 ◽  
Vol 191 (6) ◽  
pp. 1749-1755 ◽  
Author(s):  
Jeffrey G. Gardner ◽  
Jorge C. Escalante-Semerena
Keyword(s):  
Bacillus Subtilis ◽  
Coenzyme A ◽  
Acetyl Coenzyme A ◽  
Acetyl Coenzyme ◽  
New Information ◽  
Low Concentrations ◽  
Dependent Protein ◽  
Protein Deacetylase

ABSTRACT This report provides in vivo evidence for the posttranslational control of the acetyl coenzyme A (Ac-CoA) synthetase (AcsA) enzyme of Bacillus subtilis by the acuA and acuC gene products. In addition, both in vivo and in vitro data presented support the conclusion that the yhdZ gene of B. subtilis encodes a NAD+-dependent protein deacetylase homologous to the yeast Sir2 protein (also known as sirtuin). On the basis of this new information, a change in gene nomenclature, from yhdZ to srtN (for sirtuin), is proposed to reflect the activity associated with the YdhZ protein. In vivo control of B. subtilis AcsA function required the combined activities of AcuC and SrtN. Inactivation of acuC or srtN resulted in slower growth and cell yield under low-acetate conditions than those of the wild-type strain, and the acuC srtN strain grew under low-acetate conditions as poorly as the acsA strain. Our interpretation of the latter result was that both deacetylases (AcuC and SrtN) are needed to maintain AcsA as active (i.e., deacetylated) so the cell can grow with low concentrations of acetate. Growth of an acuA acuC srtN strain on acetate was improved over that of the acuA + acuC srtN strain, indicating that the AcuA acetyltransferase enzyme modifies (i.e., inactivates) AcsA in vivo, a result consistent with previously reported in vitro evidence that AcsA is a substrate of AcuA.

Virulence and Genetic Characterization of Six Baculovirus Strains Isolated From Different Populations of Spodoptera Frugiperda (Lepidoptera: Noctuidae)

2021 ◽  
Author(s):  
Ingrid Zanella-Saenz ◽  
Elisabeth A. Herniou ◽  
Jorge E. Ibarra ◽  
Ma.Cristina Del Rincón-Castro ◽  
Ilse Alejandra Huerta-Arredondo
Keyword(s):  
Biological Control ◽  
Cell Cultures ◽  
Spodoptera Frugiperda ◽  
Fall Armyworm ◽  
The United States ◽  
Infection Mechanisms ◽  
Different Populations

Abstract Fall armyworm (FAW), Spodoptera frugiperda (Smith, 1797), is a polyphagous, voracious, and economically important agricultural pest. Biological control of FAW is a strategy that must be further explored. This study evaluated six baculovirus strains isolated from infected FAW larvae from Mexico, Argentina, Honduras, and the United States. Five alphabaculoviruses (SfNPV-An2, SfNPV-Arg, SfNPV-Fx, SfNPV-Ho and SfNPV-Sin) and one betabaculovirus (SfGV-RV), were tested against FAW larvae, showing a wide diversity of virulence levels among strains when their estimated LC50s were compared, being SfNPVArg, SfNPV-Ho and SfNPV-Fx more virulent than SfNPV-An 2 , SfNPV-Sin and SfGV-RV. To determine any virulence difference in vitro studies of these isolates, Sf9 cell cultures were used. Interestingly, only ODVs from four of the test SfNPV strains showed infectivity on Sf9 cell cultures, and some differences in virulence were observed. Genomic restriction analyses and partial sequences of lef-8, lef-9 , and polh/granulin genes showed little variability among alphabaculoviruses, both, among them and with previously reported sequences. However, sequences from SfGV-RV were closer to previously reported sequences from the SfGVVG008 strain than the SfGV-Arg and SfGV-VG014 strains. The great difference in the in vivo virulence was not correlated with great similarity among the isolates. The characterization of these six baculoviruses isolates offers the basis for exploring their potential as biological control agents against S. frugiperda, as well the initial studies on their specific infection mechanisms, evolution, and ecology.

scholarly journals Bioatividade de indutores de resistência no manejo da antracnose da goiabeira (Psidium guajava L.)

2016 ◽  
Vol 42 (2) ◽  
pp. 149-154 ◽  
Author(s):  
Rommel dos Santos Siqueira Gomes ◽  
Andréa Celina Ferreira Demartelaere ◽  
Luciana Cordeiro do Nascimento ◽  
Wendel Oliveira Maciel ◽  
Danilo Bruno Néri da Silva Wanderley
Keyword(s):  
Colletotrichum Gloeosporioides ◽  
Psidium Guajava

RESUMO A cultura da goiaba apresenta perdas em torno de 40 a 60% na pós-colheita relacionadas a problemas fitossanitários, como a antracnose causada pelo fungo Colletotrichum gloeosporioides. Pesquisas com métodos alternativos utilizando indutores de resistência têm sido bastante promissoras na busca de produtos com alto potencial no controle de patógenos em pós-colheita. Assim, o presente trabalho teve como objetivo avaliar os indutores de resistência no controle da antracnose e seus efeitos na qualidade físico-química em frutos de goiabeira ‘Paluma’. Os tratamentos utilizados foram: Agro-mós®, Ecolife®, Fosfitonova K®, Cuprogarb 500®, Rocksil® e testemunha (água destilada esterilizada). Realizou-se o teste in vitro, com discos de colônia de C. gloeosporioides (0,45 cm de diâmetro) com sete dias de cultivo e, postos em meio de cultura BDA acrescidos com os indutores. Foi determinada a porcentagem de inibição do crescimento micelial de C. gloeosporioides. O ensaio in vivo foi realizado com frutos de goiabeira variedade Paluma, desinfestados e tratados com indutores. Em seguida, discos de colônia do C. gloeosporioides foram inoculados e do primeiro ao oitavo dia após a inoculação, foram feitas avaliações do diâmetro das lesões nos frutos. As análises pós-colheita foram realizadas, avaliando a perda de massa fresca, sólidos solúveis totais (SST), acidez titulável (AT), razão SST/AT e potencial hidrogeniônico (pH). Foi utilizado o delineamento inteiramente casualizado, em esquema de parcela subdivididas 6x8 (tratamentos x período de avaliação) e as médias comparadas pelo teste de Tukey a 5% de probabilidade. Os indutores Agro-mos®, Ecolife®, Fosfitonova K®, Cuprogarb 500® e Rocksil® inibiram o crescimento micelial do C. gloeosporioides in vitro, reduziram o diâmetro das lesões e mantiveram a qualidade pós-colheita em frutos de goiabeira ‘Paluma’.

scholarly journals Efeito fungitóxico do óleo essencial de aroeira da praia (Schinus terebinthifolius RADDI) sobre Colletotrichum gloeosporioides

2013 ◽  
Vol 15 (1) ◽  
pp. 150-157 ◽  
Author(s):  
L.F.G Oliveira Junior ◽  
R.B. Santos ◽  
F.O. Reis ◽  
S.T Matsumoto ◽  
W.M.S. Bispo ◽  
...  
Keyword(s):  
Colletotrichum Gloeosporioides ◽  
Tween 80 ◽  
Schinus Terebinthifolius

Neste trabalho foi avaliado o efeito do óleo essencial do fruto de Schinus terebinthifolius sobre o crescimento micelial do fungo Colletotrichum gloeosporioides in vitro, e no desenvolvimento da antracnose no período de pós-colheita em mamões. As diferentes concentrações de óleo foram diluídas em Tween 80 a 8%. No experimento in vitro foram preparados meios de cultura BDA nas concentrações de 0,05; 0,10; 0,25 e 0,50% do óleo essencial. O controle negativo foi realizado apenas com meio BDA e o controle solvente com meio BDA e Tween 80 a 8%. A inibição do crescimento do fungo foi diretamente proporcional à quantidade do óleo e a maior inibição encontrada foi de 79,07% na concentração de óleo de 0,50%. No experimento in vivo os frutos do mamoeiro foram inoculados com o fungo em quatro tratamentos: com biofilme; com biofilme mais 0,50% do óleo; com fungicida Prochloraz e frutos controle. Embora o tratamento com óleo tenha sido eficiente contra o fungo, não foi indicado comercialmente, pois apresentou valores elevados de perda de massa fresca, de firmeza, e também sintomas de fitotoxidade. O óleo tem propriedade antifúngica contra C. gloeosporioides in vitro e in vivo, contudo, não é recomendado para o mamão em função da fitotoxidez

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 Efeito In vitro e In vivo de filtrados de rizobactérias sobre Colletotrichum gloeosporioides Penz. do cafeeiro

2005 ◽  
Vol 29 (3) ◽  
pp. 553-561
Author(s):  
Gilvane Aparecida de Carvalho ◽  
Mário Sobral de Abreu ◽  
Denilson Ferreira de Oliveira ◽  
Mário Lúcio Vilela de Resende ◽  
Maria Floriana Esteves de Abreu
Keyword(s):  
Colletotrichum Gloeosporioides

Objetivou-se avaliar o efeito de filtrados derivados de culturas de rizobactérias na inibição da germinação de esporos de Colletotrichum gloeosporioides e confirmar sua ação antifúngica em relação à mancha manteigosa em mudas de cafeeiro. Foram conduzidos ensaios in vitro para testar 42 filtrados, identificando-se os de maior capacidade de inibir a germinação de esporos do fungo. Plântulas de café foram submetidas à inoculação com Colletotrichum e pulverização com quatro dos filtrados mais promissores. Os tratamentos constituíram um fatorial 4x4+2, combinando a aplicação de quatro filtrados com quatro modos de inoculação do fungo (ausência de inoculação e inoculação dois dias antes, junto, ou dois dias depois da aplicação dos filtrados). Uma testemunha absoluta e outra que recebeu somente o inóculo do fungo constituíram tratamentos adicionais. Após 35 dias, foram avaliados o crescimento do cafeeiro e a severidade da mancha manteigosa. Os filtrados apresentaram ampla variação quanto à atividade antifúngica in vitro e cinco deles inibiram completamente a germinação dos esporos. No experimento com planta, os filtrados tiveram eficácia similar contra a mancha manteigosa, com controle parcial da doença (35%). A aplicação dos filtrados teve efeito depressivo ao crescimento do cafeeiro, proporcionando menor produção de matéria seca em relação à testemunha absoluta.

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.

scholarly journals Curcumin-removed turmeric oleoresin nano-emulsion as a novel botanical fungicide to control anthracnose (Colletotrichum gloeosporioides) in litchi

2021 ◽  
Vol 10 (1) ◽  
pp. 729-741
Author(s):  
Van Cuong Bui ◽  
The Tam Le ◽  
Tuyen Hong Nguyen ◽  
Nam Thi Pham ◽  
Hoang Dinh Vu ◽  
...  
Keyword(s):  
Field Trial ◽  
Colletotrichum Gloeosporioides ◽  
Inhibitory Concentration ◽  
Particle Sizes ◽  
Control Efficacy ◽  
Potent Inhibition ◽  
Nano Emulsion ◽  
Nano Formulation

Abstract During curcumin production in Vietnam, curcumin-removed turmeric oleoresin (CRTO) has been considered as a by-product. It costs to treat the by-product to prevent environmental pollution. In this study, the by-product was utilized as an active ingredient for preparing a botanical fungicide-based nano-emulsion and evaluated for its in vitro and in vivo control efficacy against Colletotrichum gloeosporioides, a causal agent of anthracnose of litchi, in the laboratory as well as a field trial. The nano-emulsion is colloidally stable and uniform with particle sizes of 95–250 nm. CRTO nano-emulsion significantly affected various Colletotrichum species. Notably, this nano-emulsion showed potent inhibition for the mycelial growth of C. gloeosporioides and solidly suppressed the development of anthracnose on litchi fruits. In the in vitro inhibition test, the equivalent half-maximal inhibitory concentration of CRTO in nano-formulation was 0.11 mg·mL−1, which was 3.0× and 6.1× lower than IC50 values of CRTO alone (0.33 mg·mL−1) and a mixture of curcuminoids (0.48 mg·mL−1), respectively. In the field trial, the litchi anthracnose infection was effectively controlled by nano-formulation. These results suggest that CRTO nano-emulsion could be used as an alternative to harmful synthetic fungicides to control anthracnose on litchi fruits.

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