从土壤中分离出1株产β-甘露聚糖酶的优良菌株Bacillus sp.QYW-1,具有发酵周期短且产酶活力高等特性,初始酶活力21.85 U/mL。在单因素实验对培养基及培养条件优化的基础上利用Plackett-Burman实验设计对影响产酶的重要因素进行筛选。实验发现,影响该菌株产酶的重要因素是魔芋粉、蛋白胨及硫酸镁。最陡爬坡实验和Box-Behnken实验得到响应面(RSM)优化的最佳培养基为:魔芋粉26 g/L,蛋白胨10 g/L,MgSO43.8 g/L,NaCl 10 g/L,KCl 6 g/L,NaNO36 g/L,K2HPO43 g/L,初始pH6.5。在此条件下菌株发酵产β-甘露聚糖酶酶活力为233.86 U/mL,与模型预测值相符,与单因素优化后的酶活力115.62 U/mL相比,提高了102%。

The strain QYW-1 isolated from soil displayed the highest activity.Based on single factor experiments used to optimize the medium and cultural conditions,11 important factors influencing enzyme production was selected with Plackett-Burman design.PB design was established to determine the factors mainly influencing the enzyme production in the fermentation medium(konjak powder,pepdone,MgSO4).Further optimum conditions for enzyme production obtained from Box-Behnken design experiments was as follows: konjak powder 26 g/L,peptone 10 g/L,MgSO4 3.8 g/L,NaCl 10 g/L,KCl 6 g/L,NaNO3 6 g/L,K2HPO4 3 g/L,initial pH 6.5.Under the RSM-optimized conditions,the activity of β-mannanase was improved from 115.62 U/mL to 233.86 U/mL.