Partial purification and characterization of exoinulinase produced from Bacillus sp.

Inulinase are industrial food enzymes which have gained much attention in recent scenario. In this study, Inulinase producing eight bacterial colonies were isolated and screened from three different plant root tubers soil sample. Among 8 inulinase producing colonies, the higher yielding colony was selected with 25.10 U/mL for further studies. The best inulinase producing colony was identified by partial 16S rRNA gene sequence as Bacillus sp. The crude inulinase was purified by using ammonium sulphate precipitation, dialysis and ion exchange chromatography on DEAE – sephacel and obtained 1.9 purification fold with total activity 293 U. The purified enzyme was subjected to characterization studies and it was found to be stable at 30–60 °C and optimum temperature was at 55 °C. The enzyme was stable at pH 3.0–7.0 and optimum pH was at 6.5. The K(m) and V(max) value for inulinase was found to be 0.117 mg/mL and 4.45 μmol min mg(−1) respectively, demonstrate its greater affinity. Hence, this enzyme can be widely used for the production of fructose, and fructooligosaccharides, which are important ingredients in food and pharmaceutical industry.