الفهرس 
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Abstract
Ten fungal strains were used in this study, namely A. niger NRRL 2270, A. niger NRC, Aspergillus niger 6A, A. tamarii; A. nidulans; Aspergillus oryzae; A. fumigatus; Cunnghamella sp.; Penicillium sp.;. and Penicillium purpurogenum. The fungal strains were grown under optimal fermentation conditions at 30°C up to 6 days in a rotary incubator-shaker at 150 rpm on a cultivation medium. Five strains were chosen for further studies namely Aspergillus niger 6A, Aspergillus niger NRRL2270, Aspergillus niger NRC, Aspergillus fumigatus and Aspergillus oryzae and the highest values of inulinase were 79.8, 62.6, 57.2, 51.2, and 44.4 IU, respectively. Five different plant materials which underground roots and tubers were collected from local markets were used with the five selected fungal strains. They were chicory (Cichorium intibus), dahlia (Dahlia pinnata), artichoke (Helianthus tuberosus), suger beet (Beta vulgaris) and alkhrishv (Cynara cardunculus), the resultant powder was used directly for inulinase induction. The fungal strains were grown under optimal fermentation conditions at 30°C up to 6 days in a rotary incubator-shaker at 150 rpm. The purpose of this part was to investigate the optimal conditions for inulinase production by the tested fungal strains. Thus, cultural conditions such as carbon source, nitrogen source and initial pH were investigated. The fungal strains were grown under optimal fermentation conditions at 30°C up to 6 days in a rotary incubator-shaker at 150 rpm. The highest values of inulinase production by A. niger 6A in a cultivation medium containing dahlia tuber as an inulinase inducer were 59.4, 47.1, 62.7, 62.1, 56.7 and 65.1 IU in case of using (NH4)2SO4, NaNO3, NH4H2PO4, (NH4)2HPO4, NH4Cl and NH4NO3 after 120, 96, 96, 120, 120 and 96 hr. The highest values of inulinase production by A. niger 6A in a cultivation medium containing girasole as an inulinase inducer were 63.6, 28.2, 61.5, 29.4, 41.1 and 73.8 IU by (NH4)2SO4, NaNO3, NH4H2PO4, (NH4)2HPO4, NH4Cl and NH4NO3 after 72, 96, 144, 96, 120 and 96 hr of incubation, respectively. from the above results, the highest values of produced inulinase were 65.1 and 73.8 IU by NaNO3 using dahlia tubers and girasole by A. niger 6A after 96 hr, respectively. The highest values of inulinase production were 44.7 and 58.2 IU by peptone and NH4H2PO4 using dahlia tubers and girasole by A. niger NRRL2270 after 96 hr, respectively. Therefore the nitrogen source which used in the basal medium will be used in the following experiments. The optimum pH for enzyme activity obtained from A. niger 6 was 4.6, but it was of enzyme obtained by A. niger NRRL 2270. At optimum pH inulinase activities were 110.8 and 54.4 IU for A. niger 6 and A. niger NRRL 2270, respectively. The analysis of data obtained from SDS-PAGE of the partially purified inulinase from Aspergillus niger 6A, using dahlia and A. niger NRRL2270 using girasole revealed tow Coomassie-stained protein bands with MW of 43.0 kDa exo-inulinase and 31.0 kDa endo-inulinase.