产β-葡萄糖苷酶罗尔夫青霉发酵条件的优化

摘要

The fermentation condition of Penicillum rolfsii HXL was optimized by using the singlefactor test and orthogonal experiment design to improve the producing β-glycosidase ability of P.rolfsii HXL and verify the enzymatic property ofβ-glycosidase.Results:The optimized fermentation conditions of P.rolfsii HXL include 3％ bran + 4 g/L yeast extract + 0.2％ KH2 PO4 + 0.05％oo salicin,6％inoculum size,75 mL/250 mL liquid volume,initial pH 6.0,30℃,180 r/min rotation speed and 144 h incubation time.The β-glycosidase activity of P.rolfsii HXL under the optimized fermentation conditions is from 1.32 U/mL to 21.68 U/mL.The optimum temperature and pH value of β-glycosidase are 60～70℃ and 3.5～5.0.The β-glycosidase activity can remain stable when temperature and pH value are below 60℃ and 3.0 ～ 6.0.Mn2+ and Cu2+ has the activation and inhibition effect on β-glycosidase activity respectively.%为提高罗尔夫青霉(Penicillium rol sii)HXL菌株产β-葡萄糖苷酶的能力,探明β-葡萄糖苷酶的酶学性质,采用单因素与正交试验方法,对HXL摇瓶发酵条件进行统计学优化研究.结果表明:菌株HXL优化发酵条件为麸皮3％+酵母膏4 g/L+KH2PO40.2％+水杨苷0.05％,接种量6％,装液量75mL/250 mL,起始pH6.0,培养温度30℃,摇床转速180 r/min,培养时间144 h.在此条件下,菌株HXL产-葡萄糖苷酶量从原来的1.32 U/mL增至21.68 U/mL.β-葡萄糖苷酶的最适温度为60～70℃,最适反应pH 3.5～5.0;在60℃以下及pH 3.0～6.0均能保持稳定;Mn2+对酶有激活作用,而Cu2+对酶有明显的抑制作用.