Effects of malnutrition on the digestive enzymes of the large bowel of young rhesus monkeys.

The aim of the present study was to investigate the effect of mild-to-moderate protein-energy malnutrition (PEM) and rehabilitation on the digestive enzymes of the large bowel in young rhesus monkeys. The presence of these enzymes has already been reported in the large bowel by many authors. The activities of the digestive enzymes, i.e. lactase, sucrase, maltase, trehalase, glucoamylase, leucine aminopeptidase, alkaline phosphatase and gamma-glutamyl transpeptidase, from different parts of the large bowel were determined in 6 controls, 6 PEM and 6 rehabilitated young rhesus monkeys. These monkeys had been used to study the effect of malnutrition on the small intestine and the results have already been published. There was a significant decrease in the sucrase in the ascending colon (p < 0.05); maltase in all the parts of the large bowel (p < 0.05); and glucoamylase activities (p < 0.05) in the caecum segment of the large bowel in the PEM group. The activity of other enzymes, i.e. lactase, trehalase, alkaline phosphatase, gamma-glutamyl transpeptidase and leucine aminopeptidase, was unaffected in the PEM group. The changes in the enzyme activities recovered on rehabilitation of 21 weeks. The result of this study suggest that even mild-to-moderate malnutrition affects the enzyme activity of the large bowel, which recovers on rehabilitation.

Fermentation of starch to ethanol by an amylolytic yeast Saccharomyces diastaticus SM-10.

A total of fifteen yeast strains were isolated from natural sources including fruits, soil, molasses, honey and a variety of indigeneous fermented foods. Screening of these strains for growth, ethanol production and glucoamylase activity led to selection of a yeast strain SM-10 identified as S. diastaticus having maximum glucoamylase activity (80 units ml(-1)) and ethanol production from starch (3.5%). Ethanol production from wheat flour was found to be 1.75% which could be increased to 5.2% after treatment of wheat flour with pepsin, diastase and glucoamylase.

Enzymatic determination of soluble and insoluble dietary fiber in rice and wheat bran

The information about dietary fiber presents controversies in many research areas such as in nomenclature, related illnesses, recommended quantities and terminology, mainly because of lack of analytical data. Different needs and interests for the dietary fiber composition of foods and forages have led to a proliferation of methods for its analysis. This research, a further adaptation of the enzymatic method of Asp et al. (1983) for its appplication is proposed for rice and wheat bran, byproducts of agroindustries in the southern region of Rio Grande do Sul (Brazil). The inclusion of Amyloglucosidase in the proposed methodology contributed to the decrease in the content of residual starch at the end of the experiment, like Prosky et al (1992). To increase the efficiency of the enzyme system inthis type of samples, other changes were made with respect to incubation time and proteolytic enzyme concentration. In the final adaptation, a decrease of 51.33 per cent of the starch content was observed in rice bran (RB) and of 52.93 per cent in wheat bran (WB). This decrease was also verified in the model system (MS) (52.08 per cent), which demonstrates the adequacy of the proposed adaptation. With respect to the residual protein, it was verified that the measures adopted provoked a reduction of 42.15 per cent (RB), 52.19 per cent (WB) and 42.11 per cent (MS) as compared to the original method. Then the proposed conditions has been shown to be efficient in decreasing the level of interference (indigestible starch and protein) in the quantification of dietary fiber in rice and wheat bran.

Alterations in kidney enzyme pattern in acute hypervitaminosis A

The relation of excessive doses of vitamin A with various kidney pathologies is well known however, information concerning the relation of kidney enzyme activity with acute hypervitaminosis A is rather scarce. In this study we describe the kidney enzymatic alterations observed in rats that received daily intramuscular injectiosn of 10.000, 30.000, 50.000 and 100.000IU of vitamin A palmitate (VA) during seven days (TREATED GROUPS). A comparison is made with the enzyme activity in healthy rats pairfed and treated with sodium palmitte by intramuscular injection (CONTROL GROUP). The treated rats showed a proportional increase (<0.05) in activity of acid maltase, transaminases or aminotransferase (GOT and GPT), alkaline phosphatase (ALP) and acid protease with all doses of VA administered, Amylase, lipase and arginase tend to decrease (p<0.05) in activity only with doses of 50.000 and 100.000 I.U. of VA. Several factors are responsible for these findings, such as kidney necrosis due to release of lysosomal acid hydrolases produced by hypervitaminosis A.

Intestinal glucoamylase & other disaccharidases in children with protracted diarrhoea.

Brush border lactase, sucrase and glucoamylase activities were assessed in jejunal mucosal biopsy specimens from 34 children (median age 11 months; range 1.5-38) having protracted diarrhoea with failure to thrive and 8 well nourished children with normal jejunal mucosal histology (median age 10.2 months; range 2-37). All enzymes showed progressive decrease in activity which was directly in relation to increasing degree of mucosal injury (P less than 0.002). Lactase was significantly reduced even in patients with protracted diarrhoea and normal mucosa (P less than 0.05). Glucoamylase and sucrase were significantly reduced only in the presence of mucosal injury (P less than 0.01). Our data suggest that most children with protracted diarrhoea may not tolerate lactose containing feeds and may need lactose-free diets preferably based on starch. A small number of children with protracted diarrhoea, who have severe mucosal injury may not be able to handle even starch and may require diets based on short chain glucose polymers. The findings of this study, need to be corroborated with well-controlled metabolic balance studies.

Genetic study of auxotrophic and resistant mutants of Aspergillus niger and their glucoamylase production

Mutantes auxotróficos resistentes foram isolados de uma linhagem de A. niger produtora de glucoamilase. Somente um mutante resitente, mgrA2 (verde malaquita) e os auxotróficos, metA1 (metionina) e myA1 (metionina ou cisteína) näo mostraram diminuiçäo significativa de produçäo comparados com a linhagem parental. A produçäo dos diplóides heterozigotos indicou que a baixa produçäo observada nos outros mutantes poderia ser devido a efeito pleiotrópico. Quatro grupos de ligaçäo foram identificados através de segregaçäo de diplóides heterozigotos. O gene mgrA2 se mostrou recessivo e o etbA5 (resistência a brometo de etídio), semi-diminante. O segundo poderia ser usado para determinaçäo da ordem dos genes no grupo de ligaçäo I

Proceso descontínuo de síntese de amiloglicosidade por Aspergilus awamori: influência do pH e da concentraçäo inicial de polissacarídeo

Estudou-se a influência da concentraçäo inicial de polissacarídeo (So) e do pH na produçäo de amiloglicosidase por Aspergillus awaamori NRRL 3112. Foram efetuados ensaios descontínuos, a pH 4,0 e 5,0 em fermentador de 10 litros, empregando-se meio de cultura a base de farinha de mandioca. Através do estudo cinético do processo, verificou-se a partir de So = 20g/l, para ambos os valores de pH, um comportamento acentuadamente crescente da atividade enzimática final no caldo, até se atingir um valor máximo para um determinado So. Verificou-se que esta atividade máxima é significativamente maior a pH 5,0, chegando-se a aproximadamente 7000U/1 para So = 93g/1, enquanto que a pH 4,0, obteve-se 2500U/1

Produçäo e propriedades da amilase de Trichoderma pseudokoningüi / Production and proprieties of amylases of Trichoderma pseudokoningüi

Trichoderma pseudokoningii. Rifai foi isolado como contaminante em experimentos realizados sob nitrogênio líquido. Apresentou atividade amilolítica superior a de outros fungos isolados do solo ou do ambiente. Verificou-se que exuste relaçäo direta entre o crescimento do fundo e a produçäo de amilase. A maior produçäo de amilase ocorreu quando meio mineral mínimo foi suplementado com amido a 2%, farelo de trigo a 1% e líquido resultante do processamento do milho (corn steep liquor) a 1%. A amilase foi parcialmente purificada (4,9 vêzes) através de precipitaçäo com sulfato de amônio e cromatografia em Sephacryl S-200. Apresentou somente uma banda no gel corado para atividade, mas o gel para proteínas mostrou várias bandas, indicando que a preparaçäo näo está totalmente pura. A análise cromatográfica dos produtos de hidrólise, mostrou unicamente a presença de glucose, confirmando que a amilase em estudo é uma glicoamilase. O pH ótimo de atividade foi determinado ser entre 4,0 a 5,0 com máximo em 4,2. A enzima é estável na faixa de pH de 4,0 a 6,0. A temperatura ótima encontrada foi 60ªC, retendo 90% de atividade por um periodo de duas horas de pré incubaçäo a esta temperatura a esta temperatura. Ensaios de especificidade mostraram atividade superior sobre amido de milho que de batata ou amido solúvel, e que a preparaçäo atuava com menor velocidade, mas significativamente sobre amido cru. Mostrou açäo sobre o pululano, e näo sobre o ciclo dextrina ou maltose, indicando, neste caso a ausência de atividade de transglicosilase. O Km para o amido foi da ordem de 2,7 g/l

Influência da glicose na determinaçäo da atividade da amiloglicosidase / Influence of glucose on the determination of amyloglucosidase activity

Há inibiçäo da amiloglicosidase, quando se atinge 2g glicose/1 no volume de reaçäo. Este valor, além de sua importância no fenômeno de hidrólise, indica o cuidado a ser tomado na determinaçäo da atividade. Para permitir uma estimativa mais real, foi proposta a correçäo de valores, caso o limite de 2g glicose/1 seja ultrapassado