Optimization of production and partial purification of inulinase from Bacillussubtilis

Abstract

The use of inulinase enzyme for production of high fructose syrups (HFS) found more attention during that last few decades due to the less efforts and cost required compared with the traditional two-step method. In the current study, a bacterial isolate have been selected for its potential inulinase productivity. It was identified using 16S rRNA as Bacillus subtilis Inu and given the accession number “OK444102″ in the database of NCBI. Statistical methods; Taguchi Orthogonal Array and Box-Behnken, have been applied for the improvement inulinase production and the data revealed maximum enzyme activity titer (70.8 U/ml) at 15.61 g/l, sucrose; 15.94 g/l, molasses; 5.2 g/l, peptone; 5.2, pH; 32.5 °C, incubation temperature and 6 days, incubation period). The produced enzyme was purified using aqueous two phase system (ATPS) composed of Poly ethylene glycol (PEG) conjugated with salt solution (PEG/salt). The two phases in the system were studied and the data revealed that PEG 6000 (15%)/Sodium sulfate (15%) was the most effective system in the partitioning inulinase enzyme by 13.5 purification fold and 285% yield recovery in the top PEG rich phase. The isolated Bacillus subtilis is an efficient strain for production of inulinase compared with the other conducted studies.