Raffinose production using α-galactosidase from Paraphaeosphaeria sp.

An α-galactosidase for raffinose synthesis by a reverse hydrolysis reaction was searched from intracellular of endophytic fungi. About 500 strains were screened, one strain was selected and identified as Paraphaeosphaeria sp. Partially purified α-galactosidase (1 U/ml in the reaction mixture), 100 g/L galactose, and 500 g/L sucrose at 60 °C for 48 h resulted in synthesis of 13.3 g/L raffinose and 4.6 g/L planteose at a ratio of about 3:1. The data suggest that α-galactosidase was able to synthesize raffinose at a ratio higher than that of α-galactosidases derived from other fungi.

► An α-galactosidase for raffinose synthesis was searched from endophytic fungi. ► One strain was selected and identified as anamorphic state of Paraphaeosphaeria sp. ► Raffinose and planteose were synthesized at a ratio of about 3:1. ► The rate of synthesized raffinose was higher than other fungal α-galactosidases.