Yang Peizhou, Zhang Haifeng, Jiang Shaotong
The Key Laboratory for Agricultural Products Processing of Anhui Province, College of Food Science and Technology, Hefei University of Technology, Tunxi Road 193, Hefei, 230009, Anhui, China.
3 Biotech. 2016 Dec;6(2):192. doi: 10.1007/s13205-016-0512-9. Epub 2016 Sep 3.
Bioethanol is an important oil substitute produced by the sugar fermentation process. To improve the efficiency of cellulase expression of Saccharomyces cerevisiae, a eukaryotic expression vector harboring a single-enzyme-system-three-cellulase gene (sestc) was integrated into the S. cerevisiae genome by the protoplast method. Using PCR screening, RT-PCR, and "transparent circle" detection, several recombinant S. cerevisiae strains, capable of efficiently expressing the heterogeneous cellulase, were selected. The total activity of cellulase, endo-β-D-glucanase, exo-β-D-glucanase, and xylanase of the recombinant S. cerevisiae transformant (designated number 14) was 1.1, 378, 1.44, and 164 U ml, respectively, which was 27.5-, 63-, 24-, and 19-fold higher than that of the wild-type strain. The concentration of ethanol produced by the engineered S. cerevisiae strain was 8.1 gl, with wheat bran as the carbon source, under submerged conditions; this was 57.86-fold higher than that produced by the wild-type strain (0.14 gl).
生物乙醇是通过糖发酵过程生产的一种重要石油替代品。为提高酿酒酵母纤维素酶的表达效率，采用原生质体法将携带单酶系统三纤维素酶基因（sestc）的真核表达载体整合到酿酒酵母基因组中。通过PCR筛选、RT-PCR和“透明圈”检测，筛选出了几种能够高效表达异源纤维素酶的重组酿酒酵母菌株。重组酿酒酵母转化子（编号14）的纤维素酶、内切-β-D-葡聚糖酶、外切-β-D-葡聚糖酶和木聚糖酶的总活性分别为1.1、378、1.44和164 U/ml，分别比野生型菌株高27.5倍、63倍、24倍和19倍。在水下条件下，以麦麸为碳源，工程酿酒酵母菌株产生的乙醇浓度为8.1 g/l；这比野生型菌株产生的乙醇浓度（0.14 g/l）高57.86倍。
