You Yin-wei, Wang Tian-hong
State Key Laboratory of Microbial Technology, Shandong University, Jinan 250100, China.
Wei Sheng Wu Xue Bao. 2005 Feb;45(1):142-4.
The cold-adapted gram-negative rod bacterium MB-1 which could secret cellulase was screened from mud of the bottom of the Huanghai. According to the sequence of 16S rDNA, this bacterium screened was identified as one species of Pseudoalteromonas and was named as Pseudoalteromonas sp. MB-1. The gene celA encoding cold-adapted endogluanase was cloned and then jointed to pGEX-4T-1 to construct expression plasmid pGEX-celA which was expressed in E. coli BL21. Analysis to the supernatant of E. coli sonicate revealed that the concentration of GST-CelA was about 78.5 mg/L. Properties of the fusion enzyme of GST-CelA including the optimum temperature at 35 degrees C and the optimum pH about 7.2, showed that this fusion enzyme still belonged to cold-adapted enzyme and neutral enzyme. The result lays solid base for the fundamental theory and application research on cold-adapted cellulase from Pseudoalteromonas sp. MB-1.
从黄海海底淤泥中筛选出一株能够分泌纤维素酶的耐冷革兰氏阴性杆菌MB-1。根据16S rDNA序列，将筛选出的该菌株鉴定为假交替单胞菌属的一个种，命名为假交替单胞菌MB-1。克隆了编码耐冷内切葡聚糖酶的基因celA，然后将其连接到pGEX-4T-1上构建表达质粒pGEX-celA，并在大肠杆菌BL21中表达。对大肠杆菌超声破碎上清液的分析表明，GST-CelA的浓度约为78.5 mg/L。GST-CelA融合酶的性质包括最适温度为35℃，最适pH约为7.2，表明该融合酶仍属于耐冷酶和中性酶。该结果为假交替单胞菌MB-1耐冷纤维素酶的基础理论和应用研究奠定了坚实基础。
