Biochemistry characterization of α- and β-amylases from zea mays malt and statistical analysis approach of the degradation of manioc starch
2008
CURVELO-SANTANA, JOSÉ CARLOS | FERREIRA, GRAZIELA BATISTA | BIAZUS, JOANA PAULA MENEZES | DE SOUZA, ROBERTO RODRIGUES | TAMBOURGI, ELIAS BASILE
This work examined the degradation of manioc starch by amylases from maize malt and the biochemistry characterization of enzymes. Enzyme characterization showed that the maize malt amylases have optimal pH between 4.5 and 6.5, with optimal temperature between 50 and 90C; Michaelis-Menten constant (Km) and maximum velocity of starch hydrolysis (Vmax) values for starch hydrolysis by maize malt were 7.69 x 10⁻² g/L and 7.69 x 10² g/L/min, respectively. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of the eluted sample from ion-exchange expanded bed chromatography showed that molecular weights of α- and β-amylases from maize malt were of 67.4 and 47.5 kDa, respectively. The hydrolysis times had been found between 20 and 30 h, and the higher hydrolysis yield values were about 31%; it was higher than 27% (cited by literature) and was obtained at 65C and at 9 and 11% (w/v) of any starch concentration studied. The results of this work have practical uses in the hydrolysis process of starch by food industries (beers, beverages, bakeries, syrups and others). This work shows optimal conditions of using the amylases from maize malt in starch hydrolysis. Recently, a search for new energetic sources has been unleashed after the pronounced governing of various countries on a possible energetic crisis. At present, Brazil is in search of methods that will increase the ethanol offer by production of combustible alcohol. Thus, this study shows the optimal conditions to produce fermentable syrup from manioc starch and as a potential substitute to sugarcane in alcohol production.
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