两步生物法转化柚皮苷制备L-鼠李糖

考察了利用柚苷酶和酵母静息细胞作为催化剂,两步生物法转化柚皮苷制备L-鼠李糖的工艺过程。柚苷酶水解柚皮苷的最佳工艺条件是ρ(柚皮苷)=14 g/L的水溶液为底物,加酶量10 mL/L(即每升底物中加入酶的体积,下同),pH=5.5,酶解时间22 h。酵母代谢葡萄糖的最佳工艺条件是酵母用量2.5 g/L(即每升水解液中加入酵母的质量,下同),温度32℃,pH=6.0,发酵时间120 min。在30 L发酵罐中进行了小试,最终获得了质量分数大于98.5%的鼠李糖结晶85.6 g,为理论得率的86.5%。

Preparation of L-Rhamnose by Two-Steps Biotransformation of Naringin

The preparation of L-rhamnose by two-step biotransformation of naringin using naringinase and rest cells of yeast as catalyst was studied in this paper.The optimum conditions of hydrolysis were as follows: the mass concentration of naringin at 14 g/L,10 mL/L of naringinase,pH at 5.5,and reaction time of 22 h.The optimum conditions of fermentation were: the yeast dosage 2.5 g/L,the temperature at 32 ℃,pH at 6.0,and fermentation time of 120 min.A small-scale pilot was carried out in 30 L fermentor,and 85.6 g crystals of rhamnose was obtained,the purity of which was more than 98.5%.This yield accounted for 86.5% of the theoretical yield.