Zhang Qing, Zhang Wei, Lin Chaoyang, Xu Xiaoli, Shen Zhicheng
State Key Laboratory of Rice Biology and Institute of Insect Sciences, Zhejiang University, Hangzhou 310058, China.
Protein Expr Purif. 2012 Apr;82(2):279-83. doi: 10.1016/j.pep.2012.01.011. Epub 2012 Jan 28.
The thermostable endo-1,4-β-glucanase (E1) from Acidothermus cellulolyticus, is a useful enzyme for commercial hydrolysis of cellulose into glucose. A codon-optimized synthetic gene encoding this enzyme was transformed into rice (Oryza sativa L. ssp. japonica) under the control of the rice seed storage protein Gt1 promoter. The transgenic line C19 was identified as the one with the highest endoglucanase activity among the total of 36 independent transgenic lines obtained. The cellulase activity in the C19 seeds was estimated at about 830U/g of dried seeds using CMC as substrate. The enzymes produced in the seeds had an optimum pH of 5.0 and optimum temperature of 80°C, which is similar to the enzymes produced by the native bacterium host. This study demonstrates that the transgenic rice seeds could be used as a bioreactor for production of enzymes for cellulosic biomass conversion.
来自嗜热栖热放线菌的耐热内切-1,4-β-葡聚糖酶（E1）是一种可将纤维素商业水解为葡萄糖的有用酶。一个编码该酶的密码子优化合成基因在水稻种子贮藏蛋白Gt1启动子的控制下被转入水稻（粳稻亚种）。在获得的36个独立转基因株系中，转基因株系C19被鉴定为内切葡聚糖酶活性最高的株系。以羧甲基纤维素为底物，C19种子中的纤维素酶活性估计约为830U/g干种子。种子中产生的酶的最适pH为5.0，最适温度为80°C，这与天然细菌宿主产生的酶相似。本研究表明，转基因水稻种子可作为生产用于纤维素生物质转化的酶的生物反应器。
