摘要
重组N-乙酰鸟氨酸脱乙酰基酶可在重组菌BL21-pET22b-argE中高效表达,大多以不可溶的包涵体形式存在。文中研究了金属离子浓度及添加时间对该菌生长及可溶表达部分酶活力的影响。结果表明,1.0g/L的Mg2+对生物量和酶活有明显促进作用。Co2+的浓度及添加时间不同,对菌的生长及酶活力的影响结果也不同。培养起始加入Co2+会抑制菌的生长及酶活,而在1.0%乳糖诱导2.5h后加入则可解除生长抑制并促进酶活。Ni2+,Cu2+会抑制菌体的生长及酶活。Mn2+、Mo2+和B3+不影响菌的生长,对酶活有促进作用。添加金属离子后,酶活从16.90U/mL提高到251.91U/mL。
Recombinant N-acetylornithine deacetylase could be over expressed by recombinant BL21 - pET22b -argE. And most of the enzymes were expressed in the form of inclusion bodies. The effects of different metal ions on the biomass and the enzyme activities were studied. The results showed that 1.0 g/L Mg^2＋ concentration could improve both biomass and enzyme activity greatly. Different concentrations and feeding time of Co^2＋ would have different influences on biomass and enzyme activity. Contrast to the inhibition of feeding Co^2＋ at the beginning of the cultivation, adding Co^2＋ after inducing 2.5h with 1.0% lactose could overcome inhibition on the growth and increase the enzyme activity. Mn^2 ＋ , Mo^2 ＋ and B^3 ＋ had no effects on the growth, but could increase NAO activity. Ni^2 ＋ and Cu^2 ＋ inhibit both biomass and enzyme activity. With the optimal metal ions in the medium, NAO activity reached 251.91 U/mL from the original 16.90 U/mL.
出处
《食品与发酵工业》
CAS
CSCD
北大核心
2007年第1期16-20,共5页
Food and Fermentation Industries
基金
国家973项目(2003CB7160004)资助课题
