Edma Carvalho de Miranda

Purification and characterization of trypsin from Luphiosilurus alexandri pyloric cecum

Trypsin from L. alexandri was purified using only two purification processes: ammonium sulfate precipitation and anion exchange liquid chromatography in DEAE-Sepharose. Trypsin mass was estimated as 24 kDa through SDS-PAGE, which showed only one band in silver staining. The purified enzyme showed an optimum temperature and pH of 50 °C and 9.0, respectively. Stability was well maintained, with high levels of activity at a pH of up to 11.0, including high stability at a temperature of up to 50 °C after 60 min of incubation. The inhibition test demonstrated strong inhibition by PMSF, a serine protease inhibitor, and Kinetic constants km and kcat for BAPNA were 0.517 mM and 5.0 S−1, respectively. The purified enzyme was also as active as casein, as analyzed by zymography. Therefore, we consider trypsin a promising enzyme for industrial processes, owing to its stability in a wide range of pH and temperature and activity even under immobilization.

Reflexos da utilização de farelo de coco sobre o valor nutricional do filé de tilápia-do-nilo (Oreochromis niloticus Linnaeus, 1857)

The use of coconut meal may represent an alternative source to fish feeding. The purpose of this work was to assess the impact of the use of coconut meal in Nile tilapia feeding and on the nutritional value of the fish fillets. The experiment was conducted in a completely randomized design with 4 treatments (T1 - 0%, T2 - 10%, T3 - 20%, and T4 - 30% for the inclusion of coconut meal) with five repetitions. The proximate composition, cholesterol, and fatty acids were determined. There was a difference (p < 0.05) between the treatments T1 and T3 and between T2 and T3 with regard to moisture levels; between T2 and T3 with regard to lipids; T1 and all the other treatments with regard to carbohydrates, and finally between T1 and T2 and between T3 and T4 with regard to ash. The cholesterol level showed a significant gradual increase following the increase in the inclusion of coconut meal. There was also a difference (p < 0.05) between the treatments concerning the following fatty acids: C10:0; C12:0; C14:0; C18:1; C18:3 (gama); C20:3 , and C22:6 , but the nutritional quality of the product was not affected.

ANÁLISE MULTIVARIADA DA MICROFLORA EPÍFITA EM S. OFFICINARUM ENSILADA COM G. SEPIUM

EnglishThe objective of this work was to evaluated the epiphytic micro flora of sugarcane (Saccharrum officinarum L.), fresh gliricidia (Gliricidia sepium) (GNE), wilted gliricidia (GE) and mixtures ensiled. This study was conducted at the Universidade Federal de Alagoas-UFAL, from January until December 2005. The experimental design was entirely randomized in outline [(2x3x4)+4)]. The sugarcane silages added with GNE or GE were maded in the referred percentages: 100/0; 75/25; 50/50 and 25/75. There were 28 treatments, each one with three replications. Silages were kept in experimental silos (plastic boxes), sealed with sailcloth and adhesive ribbon. These silos were maintained under controlled temperature, and humidity conditions and saved from rodent presence. The silos were opened at 15, 45, 90 and 120 days, and sampled. In relation to effects of factors and variables tested, the multivariate analysis showed significant differences (p portuguesObjetivou-se com este trabalho caracterizar a microflora epifita da cana-de-acucar (C), da gliricidia fresca (GNE) e emurchecida (GE) e das misturas ensiladas. Este estudo foi desenvolvido na Universidade Federal de Alagoas, UFAL, de janeiro a dezembro de 2005. O delineamento experimental foi o inteiramente casualizado em esquema fatorial [(2x3x4)+4]. As silagens de cana-de-acucar aditivadas com GNE e GE foram confeccionadas nas proporcoes: 100/0, 75/25, 50/50 e 25/75. Os 28 tratamentos, com tres repeticoes cada, foram acondicionados em silos experimentais (baldes plasticos de 10 l), vedados com lona de PVC e mantidos sob condicoes controladas de temperatura, umidade e protecao da presenca de roedores. Os tempos de armaze-namento das silagens foram: 15, 45, 90 e 120 dias, nos quais foram abertos para a coleta de amostras. A analise multivariada mostrou-se significativa para os efeitos dos fatores e variaveis analisadas (p