赖氨酸脱羧酶发酵工艺及酶学性质

考察了蜂房哈夫尼菌(H.alveiAS1.1009)的L-赖氨酸脱羧酶对L-赖氨酸的脱羧作用,分析了培养基、温度、pH、激活剂等因素对酶活力的影响。实验结果表明,最适培养基成分为:ρ(蔗糖)=20 g/L、ρ(玉米浆)=20g/L、ρ(酵母膏)=5 g/L、ρ(牛肉膏)=3 g/L、ρ(蛋白胨)=10 g/L、ρ(氯化钠)=5 g/L、ρ(硫酸铵)=2 g/L、ρ(维生素B6)=5 g/L和ρ(L-赖氨酸)=5 g/L,100 mL发酵液中接种量为5 mL液体菌种。最佳转化工艺条件为:转化体系温度35℃、pH=5.0,ρ(菌体)=10 g/L,ρ(吐温-80)=0.15 g/L。L-赖氨酸脱羧酶在最适发酵和转化条件下比酶活可达7 984.43 U,底物转化率可达70%。

Fermentation and Properties of Lysine Decarboxylase

L-Lysine can be converted to cadaverine with lysine decarboxylase which is found in Hafnia alvei AS 1.1009.Factors affecting the enzymatic activity were studied.The optimum fermentation medium consists of ρ(saccharose)=20 g/L,ρ(corn steep liquor)=20 g/L,ρ(yeast extract)=5 g/L,ρ(beef extract)=3 g/L,ρ(peptone)=10 g/L,ρ(NaCl)=5 g/L,ρ((NH_4)_2SO_4)=2 g/L,ρ(vitamin B_6)=5 g/L and ρ(L-lysine)=5 g/L.5 mL liquid bacteria was inoculated in 100 mL zymotic fluid.The optimal fermentation conditions are temperature 35 ℃,initial pH of the buffer 5.0,ρ(bacterium)=10 g/L and ρ(Tween-80)=0.15 g/L.Enzymatic activity can rise to(7 984.43) U and conversion of the substrate reaches 70%.