Study on fermentation condition of Aspergillus niger for producing inulinase

Using inulin as the sole carbon source to screen Aspergillus niger strains with inulinase activity,17 strains were gained.3 high inulinase strains were obtained after double-screening and the maximum activities reached 25.41U·mL-1.The effect of different carbon sources and nitrogen sources were discussed.The results showed that:The best carbon and nitrogen source were inulin and yeast extract.Through orthogonal experiment,the optimal condition was obtained for producing inulinase of Aspergillus niger.The suitable fermentation contained:2% inulin content,initial pH 5.0,50mL liquid medium in 250mL flask,30℃.