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1.
Braz. j. microbiol ; Braz. j. microbiol;39(2): 301-306, Apr.-June 2008. tab
Artigo em Inglês | LILACS | ID: lil-487708

RESUMO

A Brazilian isolate of Beauveria bassiana (CG425) that shows high virulence against the coffee berry borer (CBB) was examined for the production of subtilisin-like (Pr1) and trypsin-like (Pr2) cuticle-degrading proteases. Fungal growth was either in nitrate-medium or in CBB cuticle-containing medium under both buffered and unbuffered conditions. In unbuffered medium supplemented with cuticle, the pH of cultures dropped and Pr1 and Pr2 activities were detected in high amounts only at a pH of 5.5 or higher. In buffered cultures, Pr1 and Pr2 activities were higher in medium supplemented with cuticle compared to activities with nitrate-medium. The Pr1 and Pr2 activities detected were mostly in the culture supernatant. These data suggest that Pr1 and Pr2 proteases produced by strain CG425 are induced by components of CBB cuticle, and that the culture pH influences the expression of these proteases, indicating the occurrence of an efficient mechanism of protein secretion in this fungus. The results obtained in this study extend the knowledge about protease production in B. bassiana CG425, opening new avenues for studying the role of secreted proteases in virulence against the coffee berry borer during the infection process.


O isolado brasileiro de Beauveria bassiana (CG425) que apresenta alta virulência contra a broca do café (CBB) foi analisado quanto à produção de proteases degradadoras de cutícula, tipo-subtilisina (Pr1) e tipo-tripsina (Pr2). O crescimento fúngico foi realizado em meio contendo nitrato e em meio contendo cutícula da broca em condições de pH tamponado e não tamponado. Em meio não tamponado, suplementado com cutícula, o pH da cultura caiu e as atividades de Pr1 e Pr2 foram detectadas somente em valores de pH igual ou superior a 5,5. Em culturas tamponadas, as atividades Pr1 e Pr2 foram superiores em meio suplementado com cutícula, comparativamente as atividades em meio contendo nitrato. As atividades Pr1 e Pr2 ocorreram predominantemente no sobrenadante de cultivo. Os dados obtidos sugerem que Pr1 e Pr2 produzidas pelo isolado CG425 são induzidas por componentes da cutícula da broca do café (CBB), e que o pH da cultura influencia a expressão destas proteases, indicando a ocorrência de um mecanismo eficiente de secreção por este fungo. Os resultados obtidos neste estudo aumentam o conhecimento a respeito da produção de proteases por B. bassiana CG425, abrindo novos caminhos para o estudo do papel de proteases na virulência contra a broca do café durante o processo de infecção.


Assuntos
Beauveria/crescimento & desenvolvimento , Beauveria/isolamento & purificação , Ensaios Enzimáticos Clínicos , Meios de Cultura , Microbiologia Ambiental , Fungos/crescimento & desenvolvimento , Fungos/isolamento & purificação , Técnicas In Vitro , Peptídeo Hidrolases/análise , Café , Métodos , Virulência
2.
Braz J Microbiol ; 39(2): 301-6, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24031220

RESUMO

A Brazilian isolate of Beauveria bassiana (CG425) that shows high virulence against the coffee berry borer (CBB) was examined for the production of subtilisin-like (Pr1) and trypsin-like (Pr2) cuticle-degrading proteases. Fungal growth was either in nitrate-medium or in CBB cuticle-containing medium under both buffered and unbuffered conditions. In unbuffered medium supplemented with cuticle, the pH of cultures dropped and Pr1 and Pr2 activities were detected in high amounts only at a pH of 5.5 or higher. In buffered cultures, Pr1 and Pr2 activities were higher in medium supplemented with cuticle compared to activities with nitrate-medium. The Pr1 and Pr2 activities detected were mostly in the culture supernatant. These data suggest that Pr1 and Pr2 proteases produced by strain CG425 are induced by components of CBB cuticle, and that the culture pH influences the expression of these proteases, indicating the occurrence of an efficient mechanism of protein secretion in this fungus. The results obtained in this study extend the knowledge about protease production in B. bassiana CG425, opening new avenues for studying the role of secreted proteases in virulence against the coffee berry borer during the infection process.

3.
Artigo em Inglês | VETINDEX | ID: vti-444241

RESUMO

A Brazilian isolate of Beauveria bassiana (CG425) that shows high virulence against the coffee berry borer (CBB) was examined for the production of subtilisin-like (Pr1) and trypsin-like (Pr2) cuticle-degrading proteases. Fungal growth was either in nitrate-medium or in CBB cuticle-containing medium under both buffered and unbuffered conditions. In unbuffered medium supplemented with cuticle, the pH of cultures dropped and Pr1 and Pr2 activities were detected in high amounts only at a pH of 5.5 or higher. In buffered cultures, Pr1 and Pr2 activities were higher in medium supplemented with cuticle compared to activities with nitrate-medium. The Pr1 and Pr2 activities detected were mostly in the culture supernatant. These data suggest that Pr1 and Pr2 proteases produced by strain CG425 are induced by components of CBB cuticle, and that the culture pH influences the expression of these proteases, indicating the occurrence of an efficient mechanism of protein secretion in this fungus. The results obtained in this study extend the knowledge about protease production in B. bassiana CG425, opening new avenues for studying the role of secreted proteases in virulence against the coffee berry borer during the infection process.


O isolado brasileiro de Beauveria bassiana (CG425) que apresenta alta virulência contra a broca do café (CBB) foi analisado quanto à produção de proteases degradadoras de cutícula, tipo-subtilisina (Pr1) e tipo-tripsina (Pr2). O crescimento fúngico foi realizado em meio contendo nitrato e em meio contendo cutícula da broca em condições de pH tamponado e não tamponado. Em meio não tamponado, suplementado com cutícula, o pH da cultura caiu e as atividades de Pr1 e Pr2 foram detectadas somente em valores de pH igual ou superior a 5,5. Em culturas tamponadas, as atividades Pr1 e Pr2 foram superiores em meio suplementado com cutícula, comparativamente as atividades em meio contendo nitrato. As atividades Pr1 e Pr2 ocorreram predominantemente no sobrenadante de cultivo. Os dados obtidos sugerem que Pr1 e Pr2 produzidas pelo isolado CG425 são induzidas por componentes da cutícula da broca do café (CBB), e que o pH da cultura influencia a expressão destas proteases, indicando a ocorrência de um mecanismo eficiente de secreção por este fungo. Os resultados obtidos neste estudo aumentam o conhecimento a respeito da produção de proteases por B. bassiana CG425, abrindo novos caminhos para o estudo do papel de proteases na virulência contra a broca do café durante o processo de infecção.

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