Difructose Dianhydride III Producing Inulin Fructotransferase from Microbacterium sp. S48-1

Abstract

The difructose dianhydride III (DFA III)-producing inulin fructotransferase is an important enzyme for the food industry. This manuscript reports on a DFA III-producing inulin fructotransferase from a Microbacterium sp. for the first time. The enzyme was purified 4.4-fold from the culture supernatant of the microorganism with a 13.7% yield. The enzyme exhibited maximal activity at pH 6.0 and 60°C. The enzyme activity was stable up to 65°C. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and gel filtration were used to estimate the molecular mass of the enzyme, which was determined as 45 kDa and 46 kDa, respectively. Therefore, it was predicted to be a monomer. The smallest fructo-oligosaccharide as the enzyme substrate was estimated to be GF₃.

Key words:

• difructose dianhydride III (DFA III)
• enzyme
• inulin
• Microbacterium