RESUMEN
Cyclomaltodextrin glucanotranferase (CGTase) catalyzes the degradation of starch to form alpha-, beta- and gamma-cyclodextrin. Based on cyclodextrin formation, an alkalophilic Bacillus sp. ATCC 21783 was used for its high CGTase production ability, using corn and rice flakes as substrates. Maximum enzyme production was achieved after 96 hours at pH 9.0, temperature 37 degrees C, and 1% (w/v) of either substrate together with the addition of trub. The specific enzyme activity was determined by High Pressure Liquid Chromatography (HPLC) and expressed as using International Units based on total cyclodextrin formation. Optimum conditions for this determination were studied, finding that the best results are obtained at pH 5.0, 7.0 and 9.0, temperature 55 degrees C and 3 hours of incubation in 1% (w/v) of rice flakes as starch source.
Asunto(s)
Bacillus/enzimología , Glucosiltransferasas/biosíntesis , Oryza , Ciclo del Sustrato , Zea maysRESUMEN
Saccharomyces carlsbergensis strain ATCC 9080 was grown on acid hydrolyzed brewery waste. The substrate contains 22 mg/ml of total carbohydrates of which approximately 60% represents reducing sugars such as maltose and glucose. Optimal conditions for substrate hydrolysis were 1.5% w/v sulfuric acid, 20 minutes and temperature of 110 degrees C. Maximum enzyme production was obtained in a medium containing 0.05% w/v yeast extract at 35 degrees C and at an initial pH of 6. Addition of nitrogen sources was unnecessary. Optimal conditions for alpha-glucosidase extraction from yeast included pH 7.5, 30 degrees C, and 10 minutes of sonication. Maximum hydrolysis of PNPG occurred at pH 7.5, temperature between 30 degrees C and 25 minutes of incubation. Michaelis-Menten constants and Vmax were 1 mM, 0.56 mol/min/mg of protein on P-nitrophenly-alpha-D-glucophyra-noside and 5 mV, 5 mol/min/mg of protein on maltose respectively.
Asunto(s)
Residuos Industriales , Saccharomyces/metabolismo , alfa-Glucosidasas/biosíntesis , Medios de Cultivo , Concentración de Iones de Hidrógeno , alfa-Glucosidasas/metabolismoRESUMEN
Saccharomyces carlsbergensis strain ATCC 9080 was grown on acid hidrolyzed brewery waste. The sustrate contains 22 mg/ml of total carbohydrates of which approximately 60% represents reducing sugars such as maltose and glucose. Optimal conditions for substrate hydrolysis were 1.5% w/v sulfuric acid, 20 minutes and temperature of 110 grados C. Maximum enzyme production was obtained in a medium containing 0.05% w/v yeast extract at 35 grado C and at an initial pH of 6. Addition of nitrogen sources was unnecessary. Optimal conditions for gamma-glucosidase extraction from yeast included pH 7.5, 30 grados C, and 10 minutes of sonication. Maximum hydrolysis of PNPG occured at pH 7.5, temperature between 30 grados C and 25 minutes of incubation. Michaelis-Menten constants and Vmax were 1 mM, 0.56 mol/min/mg of protein on P-nitrophenly-gamma-D-glucophyranoside and 5 mV, 5 mol/min/mg of protein on maltose respectively
Asunto(s)
Activación Enzimática/efectos de los fármacos , alfa-Glucosidasas/síntesis química , Técnicas In Vitro , SaccharomycesRESUMEN
Candida guillermondii strain ATCC 9058 was grown on liquid brewery waste. The substrate contained 22 mg/ml of total carbohydrates of which approximately 60 per cent was reducing sugars. Maximum production of riboflavin was achieved at a pH 4, temperature of 30- C, after 3 day of fermentation in a medium supplemented with biotin 1 *g/l. Under these circunstances a riboflavin yield of 220 *g/ml was achieved. No significant differences were observed upon riboflavin production on the addition to the brewery waste of nitrogen sources such as amino acids (other than methionine), inorganic ammonio, zinc, cobalt, phosphorus, magnesium, and certain iron complexing agents