中文摘要：

文章分别以碳二亚胺盐酸盐/N-羟基琥珀酰亚胺（EDC/NHS）和3-氨丙基三乙氧基硅烷/戊二醛（APTES/GA）为连接剂,处理含有羧基和羟基的多壁碳纳米管用于固定化脂肪酶,获得羧基碳纳米管固定化脂肪酶（MCNTs-COOH lipase）和羟基碳纳米管固定化脂肪酶（MCNTs-OH lipase）。固定化后酶的p H耐受性和热稳定性较游离酶得到了提高,在温度为25-50℃时均能发挥较好的催化性能,而且最适p H从7变为8,最适温度从35℃变为40℃。在4℃下储藏350 h后,MCNTs-COOH lipase和MCNTs-OH lipase的残余酶活分别为75.7%和85.3%,而游离酶只能保持约55.7%的残余酶活;在60℃下保存3 h后,游离酶已基本失活,而MCNTs-COOH lipase和MCNTs-OH lipase仍保留了54.7%和63.5%的残余酶活力。将游离酶和固定化酶应用于生物柴油的制备,游离酶在第2个批次时的转化率仅为15.2%,而MCNTs-COOH lipase和MCNTs-OH lipase在第8个反应批次时的转化率分别为60.1%和74.3%,表现出较好的重复使用性。

英文摘要：

The multi-walled carbon nanotubes （MCNTs）with -COOH and -OH were treated separately with EDC/NHS and APTES/GA as coupling agents to covalently immobilize lipase（from Candida cylindracea）, and obtained MCNTs-COOH lipase and MCNTs-OH lipase. Compare to the free lipase,the immobilized lipases show good pH tolerance and thermal stability. The immobilized lipases can show better catalytic properties between 25 ℃ to 50 ℃, the optimal pH change from 7 to 8 and the optimum temperature change from 35 ℃ to 40 ℃. The storage stability and thermal stability of the immobilized lipases have been significantly improved, stored at 4 ℃ for 350 h, the residual activity were 75.7% and 85.3%, while the free lipase can only maintain 55.7% of its initial activity. At 60 ℃ for 3 h, the residual lipase activity of the immobilized lipases were 55.7 % and 65.5 %, while the free lipase has inactivated. The immobilized lipases have good reusability in biodiesel production, MCNTs-COOH lipase and MCNTs-OH lipase can be reused for 8 cycles, while the conversion was still 60.1% and 74.3%.