Synthesis of galacto-oligosaccharides in AOT/isooctane reverse micelles by β-galactosidase

Synthesis of galacto-oligosaccharides (GOS) from lactose by β-galactosidase was investigated in AOT/isooctane reverse micelles where the enzyme was fairly stable. GOS yield increased with initial lactose concentration in both reverse micelles and aqueous system. Transgalactosylation reaction of the enzyme was strongly dependent on the molar ratio of water to surfactant (w0) of reverse micelles. At pH 7.0 and 45°C, a maximum GOS concentration from 45% (w/v) lactose solution was 51.2% (w/w) in the reverse micelles with w0=15, while a maximum of 31% in aqueous media. Effects of solvents on GOS formation were also examined.