从萌发的油菜种子中制备脂肪酶

测定不同萌发期油菜幼苗的脂肪酶活性，采用“盐析→超滤→M-Bondapak-C18 柱层析”的工艺路线，建立一种简单且高效的油菜脂肪酶纯化方法。结果表明：通过测定不同培养时间的油菜幼苗的脂肪酶比活力，发现培养6d 的油菜幼苗脂肪酶比活力最高，此时期的油菜幼苗适合作为脂肪酶提取的材料；对脂肪酶比活力为1.89U/mg的油菜蛋白粗提物采用盐析法沉淀脂肪酶时，得到脂肪酶的比活力为2.07U/mg，回收率为82.47%；采用截留分子质量为10000D 的超滤膜对脂肪酶盐析物进行脱盐和除去小分子杂蛋白处理，得到的脂肪酶的比活力为2.46U/mg，回收率为75.84%；进一步采用M-Bondapak-C₁₈ 柱层析纯化超滤液，脂肪酶最高比活力为9.14U/mg，回收率为34.13%。所得到的脂肪酶的活性达到了商品化脂肪酶的水平。

Preparation of Lipase from Germinated Rapeseed

The lipases in the germinating seeds of oil crop have high specificity and efficiency to the substrate plant oil, the main sources in biodiesel production. The lipase activity during the different stages of rapeseed germination was determined, and accordingly, lipase was purified by salting out, ultrafiltration, and M-Bondapak-C18 column chromatography sequentially. The results showed that: 1) During the different stages of germinating seeds, the lipase activity in 6-day-old seedling was at the peak. Therefore, 6-day-old seedlings were chosen as the material for lipase extraction; 2) After salting-out, the specific activity of lipase was improved from 1.89 U/mg to 2.07 U/mg, with a recovery rate of 82.47%; 3) After ultra filtration with 10000 D membrane, the specific activity of lipase was improved to 2.46 U/mg, and the recovery rate was 75.84%; 4) The specific activity of further purified lipase by C₁₈ column chromatography was improved to 9.14 U/mg, with the recovery rate being 34.13%. The activity of final lipase prepared reached the level of commercial lipase.