Optimization of Inulinase Production by a Fungal Species Isolated from Rotten Garlic Samples

Introduction: inulinases are β-fructohydrolase enzymes that catalyze the hydrolysis of inulin. recently, this enzyme has gained much importance mainly due to its ability to produce high-density fructose syrup using inulin as a raw material. in the current study, screening of inulinase-producing microorganisms was carried out from the rhizosphere soil of the dahlia plant and rotten garlic samples.materials and methods: the inulinase activity was detected with the help of 3,5-dinitrosalicylic acid (dnsa) and seliwanoff’s method, and the organism showing the highest potential was selected for further optimization studies.results: the optimum culture conditions for inulinase production, by the test fungal culture, were observed when 5% inoculum was added to the minimal medium (ph 5.5) containing 1% inulin/ costus root powder as a carbon source and 0.15% nano3/ nh4cl as a nitrogen source, and incubated at 30°c for 48h under shaker conditions (200 rpm). maximum enzyme activity was observed at ph level of 5 and temperature level of 45°c, with thermal stability noted between 35°c-55°c. the i/s value of the crude enzyme was calculated to be 0.45 indicating true inulinase activity. it showed no significant inhibition in the presence of metal ions such as zn^2+, mg^2+, and fe^3+. the ca^2+ ions showed partial inhibition whereas cu2+ ions showed an enhancement in the enzyme activity.conclusions: these factors may present the test fungal culture isolated in the present study to be a potential candidate for the production of thermo-tolerant and metal resistant inulinase enzyme in order to be used for various biotechnological processes.