RESUMO
The general use of refrigeration of raw milk has contributed to maintenance of its quality, but has induced the selection of a psychotrophic bacteria which during its growth produces heat-resistant enzymes responsible, in part, for the deterioration of long-life products. Given the condition of the prolonged refrigeration of the milk before the process, it was necessary to determine the growth curves for bacteria at temperatures between 2 degrees C and 10 degrees C and the kinetics of production of proteases in raw fresh milk, inoculated with Pseudomonas fluorescens RV1O, using an automatic fermentation system, with minimal agitation under conditions of controlled temperature and pH. The results show a development over 10(5) ufc/mL in the cultures at 6 degrees, 8 degrees and 10 degrees C during the first 30 h and proteasic activities over 30 microM p-NA/2 h getting levels of de 80-180 microM p-NA/2 h over 50 h of cultivation. Only the cultures at 2 degrees C appeared stable with inferior cell counts and without inducing enzymatic activity. At 4 degrees C an intermediate situation occurs.
Assuntos
Animais , Bovinos , Feminino , Conservação de Alimentos/métodos , Endopeptidases , Leite , Pseudomonas fluorescens , Temperatura Baixa , Meios de Cultura , Microbiologia de Alimentos , Cinética , Leite , Pseudomonas fluorescens , RefrigeraçãoRESUMO
Se hace una revision del tema de la endocarditis infecciosa de válvula nativa, en la cual se incluye la definicion aceptada hoy en dia, los aspectos etiologicos y el daño mismo desde el punto de vista patologico, asi como las implicaciones funcionales a que puede dar lugar la presencia de esta entidad. Se analizan los factores predisponentes y las causas etiologicas asi como tambien la microbiolologia concomitante y se dan pautas tanto para la prevencion como para el tratamiento.