Abstract:
Inulin, a polyfmctan, is found as the resci-ve carbohydrate in the roots and tubers
of various plants (i.e. Jerusalem artichoke, chicory and dahlia tubers). Enzymatic
hydrolysis of inulin produce syrup up to 95% fructose, fligh fructose svTup can be used
as low caloric sweetener because fructose is 1.5 to 2 times sweeter than sucrose.
P-fructofuranosidase (inulinase) from the mold Aspergillus niger Gmn 11.1 is of interest
because of its industrial potential in fmctose syrup production .
Inulinase production from Aspergillus niger Gmn 11.1, isolated from dahlia
tubers by using six different media composition was produced by batch-culture.
Inulinase activity is determined by measuring reduction sugar by using oitotoluidin
method.
The best result is found by using composition of medium III (inulin 1 % + (NH4)2
HPO4 0.5 % + MgS04 7H2O 0.05 %). The highest inulinase activity was 7.8107 x 10"^
mmol/ml/'minute, and incubation time sixt>' hours by using statistic analysis base on
DMRT. Ba.se on composition of the best medium (medium III) by variating of the carbon
source (inulin, starch, cellulose, fructose and glycerol), pH fermentation (4.5, 5.0, 5.5 and
6.0), and temperature (30°C, 40"C, and 50° C) and incubation time sixt>' hours is found
that the highest inulinase activity 3.1228 mmol'ml/minute was obtained under optimum
condition pH 4.5 and temperature 50° C with inulia as the best inducer.
