制备生物柴油用脂肪酶产生菌的诱变和筛选

Inducing and Screening of Lipase-producing Strain for Biodiesel Fuel Production

以提高全细胞生物催化制备生物柴油的效率为目的,采用紫外诱变的方法对产脂肪酶的米根霉菌株进行诱变和筛选。筛选得到的诱变株命名为LY6,脂肪酶水解酶活(4.33 U/mL)是原始菌株的4.33倍,合成酶活(0.28 U/mL)是原始菌株的1.12倍,脂肪酶水解酶最适反应pH值为7.0。将筛选得到的菌株制备成固定化全细胞生物催化剂催化大豆油转酯化制备生物柴油,在醇油比为3∶1(物质的量之比,下同)时,脂肪酸甲酯得率比原始菌株提高了41.0%,达到87.3%;在醇油比为4∶1时,最终生物柴油的甲酯得率比原始菌株提高了16.8%,达到96.1%,故经筛选得到的菌株能作为全细胞生物催化制备生物柴油的优良菌株。

In order to improve tile lipase activity of the Rhizopus oryzae strain which is used for producing biodiesel fuel, ultraviolet mutation is employed in this research. The hydrolytic lipase activity and synthetic lipase activity of the selected strain R. oryzae LY6 was 433 % and 112 % as much as that of the original strain, reaching to 4.33 and 0.28 U/mL respectively. The maximum hydrolytic lipase activity of R. oryzae LY6 was at pH value 7.0. The immobilized R. oryzae LY6 as whole cell catalyst was used to catalyze transesterification of soybean oil. When the ratio of methanol to soybean oil is 3 ： 1, the content of methyl ester in biodiesel fuel was 87.3 % , which is 41.0 % higher than the original one. When the ratio of methanol to soybean oil is 4： 1, the content of methyl ester was 96.1% , which is 16.8 % higher than the original one.