Li Nannan, Yuan Wenjie, Wang Na, Xin Chengxun, Ge Xumeng, Bai Fengwu
School of Life Science and Biotechnology, Dalian University of Technology, Dalian 116024, China.
Sheng Wu Gong Cheng Xue Bao. 2011 Jul;27(7):1032-9.
Ethanol fermentation from Jerusalem artichoke tubers by recombinant Saccharomyces cerevisiae strains expressing the inulinase gene (inu) from Kluyveromyces marxianus was investigated. The inu native and pgk promoters were used to drive the expression of the inu gene, and the inulinase was expressed as an extracellular enzyme. All positive clones (confirmed by PCR) were able to express inulinase as measured by enzyme activity in the culture supernatant, among which two clones HI6/6 and HPI6/3 were selected, and their inulinase activity and ethanol fermentation performance were compared with their wild type. The inulinase activities of 86 and 23.8 U/mL were achieved, which were 4.6-fold and 1.5-fold higher than that of the wild type. Furthermore, ethanol fermentation was carried out with the recombinants and medium containing 200 g/L raw Jerusalem artichoke meal, and ethanol concentrations of 55 g/L and 52 g/L were obtained, with ethanol yields of 0.495 and 0.453, respectively, equivalent to 96.9% and 88.6% of the theoretical value.
研究了表达马克斯克鲁维酵母菊粉酶基因（inu）的重组酿酒酵母菌株对菊芋块茎进行乙醇发酵的情况。使用inu天然启动子和磷酸甘油酸激酶（pgk）启动子驱动inu基因的表达，菊粉酶作为一种胞外酶表达。所有阳性克隆（通过聚合酶链反应（PCR）确认）在培养上清液中均能通过酶活性检测到菊粉酶的表达，从中筛选出两个克隆HI6/6和HPI6/3，并将它们的菊粉酶活性和乙醇发酵性能与其野生型进行比较。获得了86 U/mL和23.8 U/mL的菊粉酶活性，分别比野生型高4.6倍和1.5倍。此外，用重组体和含有200 g/L菊芋粗粉的培养基进行乙醇发酵，分别获得了55 g/L和52 g/L的乙醇浓度，乙醇产率分别为0.495和0.453，分别相当于理论值的96.9%和88.6%。
