Optimization of maltooligosyl fructofuranosidesproduction by recombinant β-cyclodextrin glycosyltransferase / 生物工程学报

Coupling sugar is a kind of new sweetener which can substitute sucrose. It has a good application prospect in food, medicine and other fields because of its good coloration, water retention and anti caries. The purpose of this study was to find cheap and easily available donor and acceptor, and to optimize the preparation process of coupling sugar by using β-cyclodextrin glycosyltransferase from Bacilluscirculans 251. Using sucrose as acceptor, the factors of preparing coupling sugar was optimized, including enzyme dosage, starch types, temperature, pH, ratio of starch/sucrose, and cooperation of isoamylase and β-CGTase. When 105 g/L potato starch and 95 g/L sucrose was used as substrates, the yield of coupling sugar reached 88.4%, which was catalyzed by 13.5 U/g immobilized β-CGTase and 45.0 U/g isoamylase under the conditions of pH 5.5 and 40 °C for 21 h. In this study, isoamylase and β-CGTase were used to prepare coupling sugar innovatively. This method had obvious advantages in yield and cost, which laid both theoretical and experimental foundation for the industrial enzymatic preparation of coupling sugars.

Enzymatic synthesis optimization of isoamyl butyrate from fusel oil

Many food, cosmetic and pharmaceutical industries have increased their interest in short-chain esters due to their flavor properties. From the industrial standpoint, enzyme reactions are the most economical strategy to reach green products with neither toxicity nor damage to human health. Isoamyl butyrate (pear flavor) was synthesized by isoamyl alcohol (a byproduct of alcohol production) and butyric acid with the use of the immobilized lipase Lipozyme TL IM and hexane as solvents. Reaction variables (temperature, butyric acid concentration, isoamyl alcohol:butyric acid molar ratio and enzyme concentration) were investigated in ester conversion (%), concentration (mol L-1) and productivity (mmol ester g-1 mixture . h), by applying a sequential strategy of the Fractional Factorial Design (FFD) and the Central Composite Rotatable Design (CCRD). High isoamyl butyrate conversion of 95.8% was achieved at 24 hours. At 3 hours, the highest isoamyl butyrate concentration (1.64 mol L-1) and productivity (0.19 mmol ester g-1 mixture . h) were obtained under different reaction conditions. Due to high specificity and selectivity of lipases, process parameters of this study and their interaction with the Lipozyme TL IM are fundamental to understand and optimize the system so as to achieve maximum yield to scale up. Results show that fusel oil may be recycled by the green chemistry process proposed by this study.

Enzima desramificadora de amido tipo-isoamilase durante o amadurecimento de bananas (Musa acuminata) / Debranching starch enzyme type-isoamylase during ripening of bananas (Musa acuminata)

As enzimas desramificadoras (DBE) são indispensáveis para a hidrólise das ligações `alfaï(1-6) do amido. Uma DBE tipo-isoamilase foi detectada durante o amadurecimento de banana, apresentando maior afinidade por ß-dextrina limite, seguida por glicogênio, com tamanho de subunidade estimado em 80 kDa. O sequenciamento de parte do gene da enzima de banana mostrou alta homologia com isoamilase de outros vegetais, confirmando sua identidade. A isoamilase de banana apresentou atividade, transcrição e expressão constantes durante o amadurecimento. Quando amostras de banana foram tratadas com 10 ppm de etileno, foi observada uma diminuição no nível de transcrito de isoamilase, porém sem alterações no perfil de atividade e quantidade de proteína expressa, sugerindo que a isoamilase de banana não é regulada por etileno

Pseudo-Pancreatitis Aguda Edematosa: sindrome mimetizado por una duodenitis parasitaria multiple. Analisis de 7 casos / Pseudo acute pancreatitis: a syndrome mimicked by a multiple parasitic duodenitis. Analysis of 7 case

INTRODUCTION: The aim of this presentation was to analyze a clinical syndrome characterized by repeated episodes of upper abdominal pain, markedly increased levels of both total amylase and lipase, but with normal values of pancreatic isoamylase. Besides, with the lack of morphologic changes of the pancreatic gland, either by ultrasound, abdominal tomography, or Nuclear Magnetic Resonance. MATERIAL, METHODS AND RESULTS: Five female and two male patients, with an average age of 51 +/- 3 were studied. All had been diagnosed as having acute edematous pancreatitis (ranson score < 3). Laboratory tests had disclosed eosinophilia (5-30 percent); total amylasemia (1547 +/- 398 UA/l); lipasemia (857 +/- 499 UBL/L); normal pancreatic isoamylase (72 +/- 18 UA/L). Upper endoscopy showed nonspecific signs of duodenitis sometimes with duodenal erosions. Collection studies, pre and post Sorbitol, disclosed an unexpected multiple parasitic infestation, e.g.: giardias, ascaris, amoeba, hymenolepis nana. This finding was always suggestively associated with abundant sludge (bilirrubinate cholesterol and oxalate crystals). All patients, after having been submitted to the appropriate antiparasitic medication, were rapidly relieved of their symptoms and remained free of episodes of abdominal pain. CONCLUSIONS: When the fact that all our patients had normal pancreatic isoamylase levels and lack of any morphologic distortion of the pancreatic parenchyma is associated to the notion that total amylase and lipase may have as a source the gastrointestinal mucosa, it appears as a logical inference that the clinical syndrome here discussed is indeed primarily a reflection of an extrapancreatic disease, essentially of parasitic duodenitis.

The pancreatic enzymes value in the diagnosis of acute pancreatitis and acute biliary tract diseases

El objetivo del presente trabajo fué investigar la utilidad de la determinación de lipasa e isoamilasas en el diagnóstico de pancreatitis aguda, compárandolas con la de amilasa y si la evaluación de estas enzimas permite el diagnóstico clínicos diferencial entre pancreatitis aguda y patología biliar aguda sin lesión pancreática. Se estudiaron tres grupos de pacientes. a) Control: 60 pacientes sin enfermedades digestivas. b) Pancreatitis aguda: 60 pacientes, en las que el diagnóstico fue hecho en base al cuadro clínico, análisis de laboratorio, ecografia y T. C. em 24 (40%), en las restantes 36(60%), se obtuvo además confirmación quirúrgica, c) Patología biliar aguda sin daño macroscópico pancreático, 30 pacientes en los que el diagnóstico se hizo de acuerdo al cuadro clínico, análisis de laboratorio y ecografia en 4 (13,3%) mientras que en los restantes 26(86,6%) se obtuvo confirmación quirúrgica, dentro de la semana de haber comenzado el cuadro clínico. En todos los pacientes se determinaram: amilasa en suero y orina, lipasa e isoamilasas total, pancreática y salival en suero. En el grupo con pancreatitis aguda, la sensibilidad diagnóstica fue: isoamilasa pancreática 95,5%, lipasa 95%, amilasa sérica total 93,3%, amilasuria 90%, amilasemia 78,3%. En el grupo de patología aguda biliar, sin daño pancreático, se encontraron también un número elevado de valores de las enzimas: isoamilasa pancreática 83,3%, amilasa sérica total 73,3%, amilasuria 66,6% lipasemia 63,3% amilasemia 53,3%..