Production of β-fructofuranosidase by Aspergillus japonicus

A newly isolated strain, TIT-90076, which produces β-fructofuranosidase (FFase, EC 3.2.1.26) with a high transfructosylating activity was identified as Aspergillus japonicus. The optimal conditions for the enzymatic transfructosylating reaction occur at pH 5.0 and 55°C. Sucrose is the best carbon source and yeast extract the best nitrogen source for enzymes production. Addition of MgSO·7H₂O and K₂HPO₄ shifted the morphology of the fungal growth from filamentous to pellet form; however, these salts did not affect FFase production. Antifoam-289 was the best additive for enzyme production among the polymeric and surfactant additives investigated. A central composite experimental design (CCD) and response surface methodology (RSM) were employed to derive a statistical model for the effects of sucrose and yeast extract on FFase production, and an initial concentration of 26.6% sucrose and 2.6% yeast extract was found to be optimal for the final enzyme production in batch cultures.