固定化粪链球菌酶法连续生产L-瓜氨酸

对复合诱变菌株粪链球菌Streptococcus faecalis BT001进行了固定化,利用固定化细胞中精氨酸脱亚胺酶转化L-精氨酸制备L-瓜氨酸。研究了固定化载体和菌体的配比、反应温度、反应液pH等条件对L-瓜氨酸产量的影响;通过简易颗粒强度测定仪,评估了添加不同质量分数的海藻酸钠和改性剂对颗粒强度的影响。结果表明:当包埋载体海藻酸钠质量分数为5%,菌体量为10%,改性剂硅藻土为5%,聚二甲基硅氧烷为3%,反应液pH值为6.5,反应温度为35℃时,在改进后的填充床中进行连续反应,得到的L-瓜氨酸产量可达95.6g/(L.d),摩尔产率为95.1%,且连续反应时间可达73d以上。

Enzymatic and continuous production of L-citrulline by immobilized Streptococcus faecalis cells

The optimal conditions for immobilization of Streptococcus faecalis BT001,an induced composite strain which is conserved by our lab,have been studied. The optimum conditions were found to be 5% sodium alginate,10% cells,5% diatomite and 3% methyl silicone. The arginine de-imine enzyme which was contained in the cells of Streptococcus faecalis can act as a catalyst for the conversion of L-arginine into L-citrulline. The optimum conditions for production of L-citrulline in a modified packed bed reactor were a...