Galacto-oligosaccharides (GOS) are prebiotics that have a beneficial effect on human health by promoting the growth of probiotic bacteria in the gut, in addition to having various applications in the food industry. GOS are generally produced from lactose in a reaction catalyzed by ß-galactosidase. Synthesis of GOS from whey permeate (WP) (ultrafiltration of whey, concentrated then spray dried) using surface engineered β-galactosidase in Pichia pastoris (P. pastoris) is a novel method to convert waste into a valuable product. Cell-surface display is the expression of peptides and proteins on the surface of living cells by fusing them to functional components of cells. Surface engineered cells have many potential uses. The Flo1p flocculation functional domain, thought to be located near the N terminus, recognizes and adheres non-covalently to cell-wall components such as α-mannan carbohydrates, causing reversible aggregation of cells into flocs.

ABSTRACT
Importance of whey and other nutritionalbenefit
Significance of oligosaccharides
Nature of galacto-oligosaccharides (GOS)
Need and health benefits ofgalacto-oligosaccharides (GOS)
β-Galactosidase enzyme and mechanismon lactose
Galacto-oligosaccharide production
Surface displayed enzyme production inPichia pastoris
Additional benefits of oligosaccharidetowards anti- flocculent(negative –interaction)
Conclusion and future perspectives
국문요약
References

• Ramachandran C(Department of Food Science and Biotechnology, Kangwon National University)
• Deog-Hwan Oh(Department of Food Science and Biotechnology, Kangwon National University) Correspondence to