RESUMO
The aim of this work was to develop methods for the make a rapid selection of major Aspergillus niger strains in citric acid production. A relationship between culture appearance and productivity was established also, a solid medium was designed. This medium showed early a good level of citric acid production by assayed strains. The result obtained are confirmed by ordinary submerged culture.
Assuntos
Aspergillus niger/metabolismo , Citratos/metabolismo , Aspergillus niger/isolamento & purificação , Ácido Cítrico , Meios de Cultura , Micologia/métodosRESUMO
This work was undertaken to study the use of molasses and cheese whey in culture media for growth and toxigenic activities of C. perfringens type D. Three media were used namely: 1) A modified Gordon medium 2) a molasses medium and 3) a whey medium which composition are shown in Table 1. The experiments were carried out in a 400 ml microfermentor by using 300 ml of media with automatic pH control (7,0 +/- 0,1) at 37 degrees C. Samples were taken for determination of microbial count and toxigenic activity. Fig. 1, 2, and 3 show the results obtained. The toxigenic activities obtained with the molasses and the Gordon media are similar, while it was not detected any activity in the cheese whey medium. It can be concluded that molasses could be a suitable and inexpensive basic component of culture media for toxin production by C. perfringens type D.
Assuntos
Toxinas Bacterianas/metabolismo , Clostridium perfringens/crescimento & desenvolvimento , Meios de Cultura , Lactose , Melaço , Técnicas Bacteriológicas , Clostridium perfringens/metabolismoRESUMO
Se ensayo el empleo de melaza y suero de queso en la formulacion de medios para el desarrollo y produccion de toxina de una cepa de Clostridium perfringens tipo D y se comparan los resultados con el medio de Gordon modificado mencionado en la bibliografia. Las experiencias realizadas demuestram que empleando medio de melaza se alcanzan rendimientos de toxina similares a los obtenidos con el medio de Gordon modificado, con lo cual se concluye que la melaza puede ser un componente basico economico para la produccion de toxina del microorganismo citado. Con respecto al suero de queso como componente de medios puede concluir-se que debe descartarse su empleo en procesos de tipo discontinuo como el empleado en el presente trabajo, para la produccion de toxina de Clostridium perfringens tipo D
Assuntos
Toxinas Bacterianas , Clostridium perfringens , Meios de CulturaRESUMO
This work was undertaken to study the use of molasses and cheese whey in culture media for growth and toxigenic activities of C. perfringens type D. Three media were used namely: 1) A modified Gordon medium 2) a molasses medium and 3) a whey medium which composition are shown in Table 1. The experiments were carried out in a 400 ml microfermentor by using 300 ml of media with automatic pH control (7,0 +/- 0,1) at 37 degrees C. Samples were taken for determination of microbial count and toxigenic activity. Fig. 1, 2, and 3 show the results obtained. The toxigenic activities obtained with the molasses and the Gordon media are similar, while it was not detected any activity in the cheese whey medium. It can be concluded that molasses could be a suitable and inexpensive basic component of culture media for toxin production by C. perfringens type D.
RESUMO
Se ensayo el empleo de melaza y suero de queso en la formulacion de medios para el desarrollo y produccion de toxina de una cepa de Clostridium perfringens tipo D y se comparan los resultados con el medio de Gordon modificado mencionado en la bibliografia. Las experiencias realizadas demuestram que empleando medio de melaza se alcanzan rendimientos de toxina similares a los obtenidos con el medio de Gordon modificado, con lo cual se concluye que la melaza puede ser un componente basico economico para la produccion de toxina del microorganismo citado. Con respecto al suero de queso como componente de medios puede concluir-se que debe descartarse su empleo en procesos de tipo discontinuo como el empleado en el presente trabajo, para la produccion de toxina de Clostridium perfringens tipo D