RESUMO
One variable at a time procedure was used to evaluate the effect of qualitative variables on the production of tannase from Aspergillus niger Van Tieghem. These variables including: fermentation technique, agitation condition, tannins source, adding carbohydrates incorporation with tannic acid, nitrogen source type and divalent cations. Submerged fermentation under intermittent shaking gave the highest total tannase activity. Maximum extracellular tannase activity (305 units/ 50 mL) was attained in medium containing tannic acid as tannins source and sodium nitrate as nitrogen source at 30 ºC for 96 h. All added carbohydrates showed significant adverse effects on the production of tannase. All tested divalent cations significantly decreased tannase production. Moreover, split plot design was carried out to study the effect of fermentation temperature and fermentation time on tannase production. The results indicated maximum tannase production (312.7 units/50 mL) at 35 ºC for 96 h. In other words, increasing fermentation temperature from 30 ºC to 35 ºC resulted in increasing tannase production.
Assuntos
Aspergillus niger/enzimologia , Hidrolases de Éster Carboxílico/metabolismo , Cátions Bivalentes/metabolismo , Meios de Cultura/química , Inibidores Enzimáticos/metabolismo , Fermentação , Temperatura , Fatores de TempoRESUMO
Os autores fazem um estudo da incidencia de aspiracao de conteudo da orofaringe para a traqueia em 42 pacientes (sendo 26 deles intubados e 16 traqueostomizados), utilizando o corante azul de Evans a 1% para detectar a presenca de aspiracao. Os resultados obtidos mostram indices elevados de aspiracao (da ordem de 50%), nao havendo diferenca significativa, esteja o paciente intubado ou traqueostomizado, em coma ou consciente, com sonda nasogastrica ou nao. E analisada tambem a fisiopatologia, e sao feitos comentarios de ordem pratica, principalmente sob o ponto de vista de prevencao de aspiracao