Synthesis of prebiotic isomaltooligosaccharides from starch by a combination of amylolytic enzymes

Abstract

Amylolytic enzymes have important applications in the food, pharmaceutical and biofuel industries. The synthesis of prebiotic isomaltooligosaccharides (IMOS) from starch is one of the biotransformations of greatest interest. It is a multi-enzyme process based on a first hydrolytic step (liquefaction), for which we are testing -amylases obtained from non-conventional yeasts, in particular Schwanniomyces occidentalis. To obtain syrups enriched in maltose or maltotriose, different β-amylases or maltotriose-forming enzymes are being investigated in our laboratory. The final step is a transglucosylation process catalyzed by α-glucosidases, which selectively form α(1→6) linkages between glucosyl residues. This transfer reaction is being studied with commercially available enzymes or those obtained from the yeast Xanthophyllomyces dendrorhous (formerly Phaffia rhodozyma). Immobilization of the above enzymes (in the same support or compartmentalized in different carriers) allows a better control of the multi-step process and may help to reduce the costs.