Inulin fructotransferase (DFAIII-producing) from Arthrobacter ureafaciens D13-3

An inulin fructotransferase (DFA III-producing) [EC 2.4.1.93] from Arthrobacter ureafaciens D13-3 was purified and characterized. The enzyme was purified from culture supernatant of the microorganism 22.3-fold with a yield of 23.6%. The enzyme showed maximum activity at pH 5.5 and 50 °C. The enzyme activity was stable up to 70 °C after 30 min heat treatment. The molecular mass of the enzyme was estimated to be 40 kDa by SDS-PAGE and 43 kDa by gel filtration, and the enzyme was considered to be a monomer. The smallest fructo-oligosaccharide as the substrate was estimated to be GF3 (nystose). The N-terminal amino acid sequence (12 amino acid residues) was analyzed as TTVYDTTVDVP.