环状芽孢杆菌A_6产生的果胶酶和木聚糖酶分离纯化及酶学性质

Purification and properties of the pectinase and xylanase from parasitizing Bacillus circulars A_6

寄生于南方亚麻茎杆上的环状芽孢杆菌发酵产生的果胶酶和木聚糖酶经采用(NH4)_2SO_4沉淀与半透膜透析,CM-Sephadex C-50凝胶离子交换柱层析,Sephadex G-100凝胶柱层析分离纯化.经鉴定果胶裂解酶和木聚糖酶基本达电泳纯,果胶裂解酶两个亚基的相对分子质量分别为32253,27400,木聚糖酶两个亚基的相对分子质量分别为86 489,57422;果胶裂解酶和木聚糖酶最适反应温度为45℃;果胶裂解酶最适反应pH值为10.5,木聚糖酶最适反应pH值为7;对果胶裂解酶而言,K^+,Mg^(2+)有轻度的抑制作用.Fe^(2+),Cu^(2+)有强抑制作用,Ca^(2+)有一定的激活作用;对木聚糖酶,K^+,Mg^(2+)有轻微抑制作用,Cu^(2+)有强抑制作用,Ca^(2+)和Fe^(2+)有一定的激活作用.

The pectinase and xylanse from Bacillus circulars A6 parasitizing on flax in South China was separated and purified by （NH4）2SO4 sedimentation and membrane dialysis, CM-Sephadex C-50 gel anion exchange filtration and Sephadex G-100 gel filtration. The pectinase and xylanase got electrophoretic purity; there are two subunits in the pectinase, their molecular weight is 32 253 and 27 400, respectively; there are two subunits in the xylanse, their molecular weight is 86 489 and 57 422, respectively, the optimal reaction temperature of depolymerizing enzyme and xylanse was 45℃ ; the optimal reaction pH of depalymerizing enzyme was 10.5 ; the optimal reaction pH of xylanse was 7; The depolymerizing enzyme was slightly inhibited by K^＋, Mg^2＋, seriously inhibited by Fe^＋, Cu^2＋, and to some extent activated by Ca^2＋; the xylanse was lightly inhibited by K^＋, Mg^2＋, seriously inhibited by Cu^2＋, and activated by Fe^2＋, Ca^2＋.