Alternative method for quantification of alfa-amylase activity.
A modification of the sensitive agar diffusion method was developed for macro-scale determination of alfa-amylase. The proposed modifications lower costs with the utilisation of starch as substrate and agar as supporting medium. Thus, a standard curve was built using alfa-amylase solution from Aspergillus oryzae, with concentrations ranging from 2.4 to 7,500 U.mL-1. Clear radial diffusion zones were measured after 4 hours of incubation at 20 A degrees C. A linear relationship between the logarithm of enzyme activities and the area of clear zones was obtained. The method was validated by testing alpha-amylase from barley at the concentrations of 2.4; 60; 300 and 1,500 U.mL-1. The proposed method turned out to be simpler, faster, less expensive and able to determine on a macro-scale alpha-amylase over a wide range (2.4 to 7,500 U.mL-1) in scientific investigation as well as in teaching laboratory activities.
Farias
D F
DF
Departamento de Biologia, Universidade Federal do Ceará, Fortaleza, CE, Brazil.
Carvalho
A F U
AF
Oliveira
C C
CC
Sousa
N M
NM
Rocha-Bezerrra
L C B
LC
Ferreira
P M P
PM
Lima
G P G
GP
Hissa
D C
DC
D000362:Agar; D001236:Aspergillus oryzae / Q000201:enzymology*; D002623:Chemistry Techniques, Analytical / Q000191:economics / Q000379:methods*; D004058:Diffusion; D015203:Reproducibility of Results; D000516:alpha-Amylases / Q000032:analysis*
D000362:Agar; D000516:alpha-Amylases