Atividade antibacteriana em alguns extratos de vegetais do semi-árido brasileiro

Espécies nativas ou endêmicas do semi-árido brasileiro foram investigadas com o intuito de se descobrir novas drogas antimicrobianas. Os ensaios foram realizados contra cepas padrões de Staphylococcus aureus e Escherichia coli através do método de difusão em disco. Dos 137 extratos de vegetais avaliados, sete apresentaram atividade significativa contra o Staphylococcus aureus. Os extratos ativos foram preparados a partir de espécies pertencentes às famílias Leguminosae e Rutaceae e serão futuramente fracionados com o intuito de se chegar às moléculas ativas.

Species native or endemic of the Brazilian semi-arid were investigated with the intention of discovering new antibacterial drugs. The rehearsals were accomplished against standard strains of Staphylococcus aureus and Escherichia coli through the diffusion method in disk. Of the 137 extracts of appraised vegetables, seven presented significant activity against the Staphylococcus aureus. The active extracts were prepared starting from species belonging to the Leguminosae and Rutaceae families and they will be fractional hereafter with the intention of arriving to the active molecules.

Mutantes con alta producción de butanol de una cepa de Clostridium solventogénica aislada de alpechín / [Mutants with high butanol production from a strain of solventogenic Clostridium isolated from olive black-water]

Butanol high producing mutants of a solventogenic Clostridium sp. capable of degrading olive black water, were selected according to ethanol or butanol resistance after treatment with N-methyl-N’-nitro-N-nitrosoguanidine. Mutants were quickly screened from isolated colonies and then characterized in standard culture conditions.

Producción de biomasa y depuración biológica de vinaza de destilería en un proceso de dos etapas / [Biomass production and biological purification of distillation slops in a 2-step process]

In order to lower the chemical demand (COD) of slops from cane molasses alcohol a treatment of two steps which allows the production of single cell protein of Candida utilis and Paecilomyces variotii has been performed. Its use reduces the treatment cost. In the first step the slops without sterilization supplemented with ammonium sulphate (5 g.l-1) and dipotassium phosphate (0.5 g.l-1) was inoculated with C. utilis and P. variotii. The yield was 24 and 18 g.l-1 of dry biomass and COD reduction of 36 and 75

respectively. In the second step, the remainder effluents were treated with Aspergillus niger. The final COD reduction attained was 93 and 92

Influencia de la velocidad de crecimiento sobre la formacion de toxinas en microorganismos del genero Clostridium. / Influence of growth velocity on the toxin production in microorganisms of the genus Clostridium

Se analizo la relacion entre velocidad de crecimiento y formacion de toxina en cultivos de Clostridium botulinum tipo A y Clostridium perfringens tipo D obtenidos con distintos medios y sistemas de cultivo Los resultados obtenidos indican una relacion inversa entre velocidad de crecimiento y actividad toxigenica especifica

Empleo de melaza y suero de queso en medios de cultivo para el desarrollo y produccion de toxina de Clostridum perfringens tipo D. / Use of molasses and cheese whey in culture media for growth and production of toxins of Clostridium perfringens type D

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