dc.description.abstract | The α-galactosidase is important industrial enzyme, used both in food and feed industry,
that hydrolyses variety of non-digestible oligosaccharides with α-1,6-galactosydic bonds,
thus allowing wider consumption of soybean-derived products [1,2]. The aim of this work
was to produce this enzyme by submerged fermentation with Aspergillus oryzae DSM
1862 using several agricultural by-products (soybean meal, soybean flour, wheat bran,
barley bran) as substrates. Soybean flour was proved to be the substrate of choice, being
the most productive (3.34 IU/ml), and at the same time easiest for handling. In order to
optimize cultural conditions for obtaining highly active preparations, different parameters
were varied: substrate concentration (2-50 %), fermentation time (1-7 days), size of
inoculum (0.5-5%). The highest activity was achieved after 6 days submerged
fermentation using 2 % soybean flour and with 0.5 % of inoculum, since it showed no
influence on produced activity. Furthermore, purification was performed by simple
acetone precipitation and this was later proved by electrophoresis. The purified
preparation was characterized, and it was concluded that optimal conditions for raffinose
hydrolisis were 50 ᵒC and pH 4.8. | sr |