Thermobifida fusca产角质酶摇瓶发酵条件研究

CUTINASE PRODUCTION CONDITIONS WITH THERMOBIFIDA FUSCA

研究了环境和营养条件等对嗜热放线菌Thermobifida fusca WSH03-11生长及产角质酶的影响;并考察了苹果角质对角质酶诱导效果,分析了该菌产角质酶的机理.摇瓶研究确定了角质酶发酵的最佳种子培养基组成为:90 g L-1可溶性淀粉、5 g L-1牛肉膏、5 g L-1酵母膏、5 g L-1NaCl、2 g L-1K2HPO4和1%微量元素液,生物量最高达18.5 gL-1,种龄取35～40 h.最佳环境条件为:pH 8.0、5%接种量、培养温度50℃.最佳发酵培养基组成为:1.5%乙醇、5 gL-1蛋白胨、5 g L-1酵母膏、2 g L-1K2HPO4、5 g L-1NaCl和1%微量元素液.发酵培养基中添加角质对角质酶合成与分泌有诱导作用,T.fusca的产酶机制为诱导型.采用上述最佳培养条件产角质酶为3.8 U mL-1.

The conditions for the growth of Thermobifutafusca WSH03-11 and cutinase production were investigated, and the effect of cutin from apple cuticle on enzyme production was studied. The optimum culture conditions, 90 g·L^-1 soluble starch, 5 g·L^-1 beef extract , 5g·L^-1 yeast extract, 5 g·L^-1 NaCl , 2 g·L^-1 K2 HPO4, 1% trace-elements solution and pH 8.0, were determined. Liquid seed of 35 - 40 h was inoculated into fermentation medium with 5 % inoculation volume. The high level of enzyme production （3.8 U·mL^-1 in contrast to former 1.1 U·mL^-1） was achieved with 1.5% alcohol as carbon source. Furthermore, 4 g· L^-1 apple cutin played a key role in cutinase excretion and higher cutin content showed no obvious effect. This study indicated the possibility that a little cutin could induce high activity of cutinase. Fig 4, Tab 3, Ref 9