Isolation and Characterization of Endo-inulinases from Arthrobacter sp. S37

The crude enzyme prepared from the culture supernantant of Arthrobacter sp. S37 was purified by Phenyl Toyopearl column chromatography. Six endo-inulinases were detected by activity staining on native PAGE and named Inu I to Inu VI. Endo-inulinase were further purified by DEAE cellulose column chromatography and band slicing. Inu II~VI produced mainly inulotriose (F3) and inulotetraose (F4) as well as a small amount of inulobiose (F2) and fructose in contrast to Inu I producing F3, F4 and F5 from inulin. The N-terminal amino acid sequence of native and six CNBr-cleaved fragment of Inu VI were determined. No homology was found in amino acid sequences between Inu VI and other fructan hydrolase including invertase reported.