重组β-甘露聚糖酶制备低聚葡甘露糖工艺条件的优化

研究了利用自主构建的重组毕赤酵母菌株GS115/Auman26A所产β-甘露聚糖酶水解魔芋粉制备低聚葡甘露糖的工艺条件。以底物魔芋粉的水解率为指标，通过单因素试验确定酶法制备低聚葡甘露糖的酶解条件如下：加酶量60 U/g，酶解温度40 ℃，魔芋粉质量浓度30 g/L，酶解时间5 h。魔芋粉水解率和酶解液还原糖质量浓度分别为53.3%和10.45 mg/mL。超滤后的酶解产物经高效液相色谱检测可知组分主要以低聚葡甘露糖为主，其中还原性单糖占9.83%，二糖以上的低聚葡甘露糖占90.17%。
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