Single-step purification, characterization and immobilization of a sucrose isomerase from Erwinia sp.

• Sucrose isomerase from Erwinia sp. was purified using only one step.
• Crude and purified sucrose isomerase were successfully characterized with RSM.
• Purified sucrose isomerase converted sucrose into 63% of isomaltulose.
• Conversion of sucrose into isomaltulose catalyzed by immobilized enzyme was optimized.
• Immobilized sucrose isomerase converted sucrose into 64% of isomaltulose.

After single-step purification to 17-fold purity, the sucrose isomerase obtained from Erwinia sp. showed specific activity of 38.75 U/mg of protein and a molecular mass of 65 kDa. The optimal pH and temperature range were 6.3 and 30–35 °C, respectively, resulting in enzymatic activities higher than 60 U/mL and 22 U/mL for the crude and purified enzymes, respectively. Both enzymatic preparations presented greater stability in the pH range 5.0–7.0 and at temperatures below 30 °C. The purified sucrose isomerase converted sucrose into 63% of isomaltulose and 30% of trehalulose at pH 6.3 and 33 °C. The optimal reaction conditions for the conversion of sucrose into isomaltulose catalyzed by the immobilized sucrose isomerase was at a pH range 6.0–6.5 and 35–40 °C.