iajnfsIAJNFSIAJNFS2709-947410.47310/iajnfs.2025.v06i01.001Optimum Production of Novel Dextranase From A Local Isolate and Characterization of The PurifiedMustafaM. OmarUniversity of Kirkuk/College of AgricultureDextranase (DN) has garnered attention for its capacity to hydrolyze dextran-derived oligosaccharides with prebiotic characteristics, creating new opportunities for its application in functional foods. This study produced DN from Bacillus amyloliquefaciens, and the optimum production was determined from the components and conditions. It was found that the best was carbonic sources by yellow cornmeal, a concentration of 2.0%. Then, the best nitrogenic source was found to be peptone in a concentration of 3.0%. The best hydrogen number was 7.0. Their incubation temperature of 45 ◦C showed higher activity, while the fermentation time was 48 hours, which was the best incubation duration. The volume of inoculums is 2×108 cells/ml, which was the best higher activity and qualitative. DN was purified by sedimentation, ion exchange, and gel filtration chromatography; the recovery reached 30.16%, and the purification fold was 8.28 in the final purification. Then, the characteristics of DN found that the optimum activity pH was 7.0, and stability ranged from 6.0 to 7.0. Then, the optimum activity temperature was 50 °C, and the enzyme retained its complete stability between 30-45 °C. Finally, the molecular weight of approximately 58 kilodaltons was detected by gel filtration.