Purification and properties of intracelluar exo- and endoinulinases from Aspergillus niger strain 12

Exo- and endoinulinases were extracted from mycelia of Aspergillus niger strain 12 using quartz sand and purified by DEAE-Cellulofine A-500, Sephadex G-100, and Sephadex G-200 chromatographies. The intracellular enzymes were homogeneous as judged by SDS-polyacrylamide gel electrophoresis. The purified exoinulinase P-2 had specificactivities of 6.6 U/mg toward inulin and 22 U/mg toward sucrose. The endoinulinase P-3 showed 108 U/mg toward inulin, but no activity toward sucrose. M sub(r)s of exoinulinase P-2 and endoinulinase P-3 were determined by gel filtration using Sephadex G-200 as 47 and 56 kDa, respectively. Optimal pH and temperature for enzyme activity were pH 5.0 and 55 deg C for P-2, and pH 5.3 and 45 deg C for P-3. Both the enzymes were activated by Mn sup(2+), and inactivated by Ag sup(+), Hg sup(2+), or p-chloromercuribenzoate. Inulinases P-2 and P-3 exhibited apparent K sub(m) values of 5.8 and 0.80 mM, respectively. in the test animals during the time was lower than that in the control animals. With regard to the viability of piglets, an interesting result was obtained. Namely, when compared with the previous data of the same sows, viability of piglets in the test animals in the present data showed about 15 % higher value than that in the previous data, whereas that in the control animals in the present data showed only about 3 % higher than that in the previous data. Therefore, it is considered that SDB pellet feeds, when fed to the sows, showed a function to enhance the viability of piglets. In addition, when the cause of the death of the piglets was surveyed in detail in this relation, it was found that piglets in the control group died in general with disease, while those in the test group died with accident such as being pressed to death. Vitamin E content and antibody titer in colostrum were revealed to tend to be higher in the test animals fed on SDB pellet feeds than those in the control. Thus it can be asserted again that SDB pellet feeds, when given to maternal sows, have a function for piglets to prevent from infectious diseases (defensive function). With regard to the growth of piglets at an early stage during four weeks after birth, when SDB pellet feeds were given to their mothers, average body weight gain and average daily gain of piglets were slgnificantly higher in the test group than those in the control. From these results, the following conclusion can be derived: the formula feed containing SDB pellet feed, when given to sows, decrease the exhaustion of body composition of the sows during gestation and lactating periods, stimulate the growth of piglets, decrease the incidence rate by enhancing the defensive function of piglets and therefore enhance the viability of them.