Gao Gang, Mao Run-Qian, Xiao Yue, Zhou Jing, Liu Yu-Huan, Li Gang
School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, People's Republic of China.
Guangdong Entomological Institute, Guangzhou, 510260, People's Republic of China.
World J Microbiol Biotechnol. 2017 Jun;33(6):114. doi: 10.1007/s11274-016-2182-5. Epub 2017 May 9.
The endoglucanase gene endo753 from Aspergillus flavus NRRL3357 strains was cloned, and the recombinant Endo753 was displayed on the cell surface of Saccharomyces cerevisiae EBY100 strain by the C-terminal fusion using Aga2p protein as anchor attachment tag. The results of indirect immunofluorescence and Western blot confirmed the expression and localization of Endo753 on the yeast cell surface. The hydrolytic activity test of the whole-cell enzyme revealed that Endo753 immobilized on the yeast cell surface had high endoglucanase activity. The functional characterization of the whole-cell enzyme was investigated, and the whole-cell enzyme displayed the maximum activity at pH 8 and 50 °C. The enzyme was stable in a pH range of 7.0-10.0. Furthermore, the whole-cell enzyme displayed high thermostability below 50 °C and moderate stability between 50 and 70 °C. These properties make endo753 a good candidate in bioethanol production from lignocellulosic materials after displaying on the yeast cell surface.
克隆了来自黄曲霉NRRL3357菌株的内切葡聚糖酶基因endo753，并通过使用Aga2p蛋白作为锚定附着标签的C末端融合，将重组Endo753展示在酿酒酵母EBY100菌株的细胞表面。间接免疫荧光和蛋白质印迹结果证实了Endo753在酵母细胞表面的表达和定位。全细胞酶的水解活性测试表明，固定在酵母细胞表面的Endo753具有较高的内切葡聚糖酶活性。对全细胞酶的功能特性进行了研究，该全细胞酶在pH 8和50℃时表现出最大活性。该酶在pH 7.0-10.0范围内稳定。此外，全细胞酶在50℃以下表现出高耐热性，在50至70℃之间表现出中等稳定性。这些特性使endo753在展示于酵母细胞表面后成为从木质纤维素材料生产生物乙醇的良好候选者。
