College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China.
J Agric Food Chem. 2012 Mar 14;60(10):2546-53. doi: 10.1021/jf204556u. Epub 2012 Mar 5.
A metagenomic library of China Holstein cow rumen microbes was constructed and screened for novel gene cluster. A novel feruloyl esterase (FAE) gene was identified with a length of 789 bp and encoded a protein displaying 56% identity to known esterase sequences. The gene was functionally expressed in Escherichia coli BL21 (DE3), and the total molecular weight of the recombined protein was 32.4 kDa. The purified enzyme showed a broad specificity against the four methyl esters of hydroxycinnamic acids and high activity (259.5 U/mg) to methyl ferulate at optimum conditions (pH 8.0, 40 °C). High thermal and pH stability were also observed. Moreover, the enzyme showed broad resistance to proteases. FAE-SH1 can enhance the release of ferulic acid from wheat straw with cellulase, β-1,4-endoxylanase, β-1,3-glucanase, and pectase. These features suggest FAE-SH1 as a good candidate to enhance biomass degradation and improve the health effects of food and forage.
构建并筛选了中国荷斯坦奶牛瘤胃微生物的宏基因组文库，以寻找新型基因簇。鉴定到一个长度为 789bp 的新型阿魏酸酯酶（FAE）基因，其编码的蛋白与已知酯酶序列具有 56%的同源性。该基因在大肠杆菌 BL21（DE3）中得到功能表达，重组蛋白的总分子量为 32.4kDa。纯化后的酶对 4 种羟基肉桂酸甲酯表现出广泛的特异性，在最适条件（pH8.0，40°C）下对阿魏酸甲酯的活性（259.5U/mg）较高。该酶还表现出较高的热稳定性和 pH 稳定性。此外，该酶对蛋白酶具有广泛的抗性。FAE-SH1 可与纤维素酶、β-1,4-内切木聚糖酶、β-1,3-葡聚糖酶和果胶酶协同作用，提高小麦秸秆中阿魏酸的释放。这些特性表明 FAE-SH1 有望提高生物量降解效率，改善食品和饲料的健康效应。
