He X S, Shen R Q, Sheng Z J
Institute of Genetics, Fudan University, Shanghai.
Yi Chuan Xue Bao. 1990;17(1):46-52.
Using the gene expression vector pFDC11 for Bacillus stearothermophilus CU21, a recombinant plasmid pFDX1 was constructed, which carries the Pseudomonas-derived xylE gene coding for Catechol 2,3-dioxygenase (CatO2ase). CatO2ase activity can be detected from CU21 (pFDX1) cells grown at 48 degrees C. This result indicates that the promoterless xylE gene can be expressed in a thermophilic host under the direction of a promoter from a thermophilic bacterium. By selecting Kmr mutants at elevated growth temperature, a segregant CU21-161 was obtained, the xylE gene expression of which at 55 degrees C and 60 degrees C was much higher than that of the parental strain. A method for CatO2ase assay with suspension of intact cells was also reported in this paper.
利用嗜热脂肪芽孢杆菌CU21的基因表达载体pFDC11构建了重组质粒pFDX1，该质粒携带源自假单胞菌的编码儿茶酚2,3-双加氧酶（CatO2ase）的xylE基因。在48℃生长的CU21（pFDX1）细胞中可检测到CatO2ase活性。该结果表明无启动子的xylE基因可在嗜热宿主中在嗜热细菌启动子的指导下表达。通过在升高的生长温度下选择卡那霉素抗性突变体，获得了一个分离株CU21-161，其在55℃和60℃时的xylE基因表达远高于亲本菌株。本文还报道了一种用完整细胞悬浮液测定CatO2ase的方法。
