Optimization of Hydrolytic Conditions for Glucomannan-Oligosaccharides by Recombinant β-Mannanase

Abstract:

The hydrolytic conditions of konjac powder were optimized for glucomannan- oligosaccharides（GMOS） by recombinant β-mannanase produced from Pichia pastoris GS115/Auman26A. The condition was optimized using the single factor test with the hydrolysis rate of substrate as the index. The optimized enzymatic condition was determined to use 60 U enzyme per gram konjac powder and 30 g/L konjac powder at 40 ℃ for 5 h enzymolysis．The hydrolysis rate of konjac powder and reducing sugar concentration were 53.3% and 10.45 mg/mL，respectively. The enzymatic hydrolysate after ultrafiltration was detected by high performance liquid chromatography （HPLC）. The hydrolysate was mainly composed by glucomannan-oligosaccharides，including 9.83% reducing monosaccharide and 90.17% glucomannan-oligosaccharides. This research can greatly improve the added value of konjac powder and lay the research foundation for further refining and functionalization of GMOS.