Characterization and recovery of alfa and beta amylases enzymes by expanded bed adsorption systems / Caracterização e recuperação das enzimas alfa e beta - amilases em sistema de adsorção em leito expandido

AUTOR(ES)
DATA DE PUBLICAÇÃO

2006

RESUMO

Aiming to development of new technologies, in this work a and b-amylases recovery from maize (Zea mays) malt by expanded bed adsorption (EBA) was studied in order, to aggregate value to the maize culture which is diffused into our Country. Thus, the optimization of the manufacture steps of maize malt, since the germination (changing the time) until the drying process (changing of time and temperature) were make to obtain this product with good activity. The hydrodynamic characterization of EBA column was making to evaluation of effects of: phosphate (at 22°C) and Tris/HCl buffer, with or without maize malt, on the bed fluidization using the Amberlite IRA 410 ion-exchange resin. The effects of bed (4 cm) and expanded bed height (8, 12 and 16 cm), pH (5, 6 e 7) and buffer type (phosphate or Tris/HCl, both 0.05M) on enzyme recovery were observed under fixed conditions for elution (NaCl 0.25M at 14mL/min). The results showed that maize seeds germination must be stopped in the 4 days and drying process conducted at 54°C for 5-6 h, to obtain the maize malt with good enzymatic activity. Richardson-Zaki equation fitted to behavior of the resins fluidization on the effect of factors studied in this work, and the hydrodynamic study showed that height equivalent to the theoretical plates (HETP), axial dispersion (Daxial) and Peclet number (Pe) increased using higher bed height and voidage. The use of phosphate buffer increased to the affinity between resins and enzymes; while the Tris/HCl buffer was not promoted to enzymes adsorption on resins. Amylase recovery by expanded bed was more effective than fixed bed chromatography and increased using 8 cm (two expansion degrees) and pH 7. The purification factor was of 500 times, due to reduction of impurity. Thus, this work had contributed to found of optimal conditions of a e b-amylases production from maize (Zea mays) malt, at high enzymatic potential and good commercial acceptance, and in this way to aggregate value to the maize culture

ASSUNTO(S)

adsorção maize malte amylases malte adsorption expanded bed leito fluidizado enzymes milho diastase enzimas

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