Rhodococcus rhodochrous tg1-A6腈水解酶的表达和催化研究

Expression and catalyzing process of the nirilase in Rhodococcus rhodochrous tg1-A6

采用紫外线和氯化锂诱变得到一株名为Rhodococcus rhodochroustg1-A6的菌种,该菌经过培养基和培养条件的优化能够产生高酶活的腈水解酶。优化培养条件为:温度28℃、摇床转速200 r/min、种子培养20 h后以6%接种量接种于产酶培养基,初始pH 7.0,300 mL摇瓶装液量为40 mL。酶活达到21.96 U/mL。在含一定菌体的100 mL反应体系中,经过10 h连续43次补加底物丙烯腈,能使产物丙烯酸的质量浓度累积到414.5 g/L。

A wild strain Rhodococcus rhodochrous was mutated by using UV light and Lithium chlorinate,and a mutant named tg1-A6 with high nitirlase activity was obtained.To improve the production of nitrilase,the culture medium and culture conditions were optimized:at 28℃,with 200 r/min of rotating speed,20 h of the seed culture time,6% of seed volume,7.0 of the initial pH value,and 40 mL medium loaded in a 300 mL flask.Under those optimized conditions the nirilase activity can reach 21.96 U/mL after 120 h.In a reaction mixture of 100 mL,414.5 g/L acrylic acid accumulated with 43 feedings of acrylonitrile during a 10-hour reaction.