β-甘露聚糖酶高产菌株发酵条件优化

摘要

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,NaNO3 6 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, Mg-SO4 3. 8 g/L, NaCl 10 g/L, KC1 6 g/L, NaNO3 6 g/L, K2HPO4 3 g/L, initial pH 6. 5. Under the RSM-optimized conditions, the activity of B-mannanase was improved from 115. 62 U/mL to 233. 86 U/mL.