Department of Bioengineering, Zhengzhou University, 100 Kexue Road, 450001, Zhengzhou, People's Republic of China.
Mol Biol Rep. 2010 Apr;37(4):1923-9. doi: 10.1007/s11033-009-9635-y. Epub 2009 Aug 8.
A novel bacterial strain with high cellulase activity (2.82 U/ml) was isolated, and then identified by its morphological character and 16S rRNA sequence, and named Bacillus subtilis strain I15. The extracellular thermostable cellulase exhibited the maximum activity at 60 degrees C and pH 6.0. It was very stable since more than 90% of original CMCase activity was maintained at 65 degrees C after incubation for 2 h. The cellulase gene, celI15, was cloned and extracellularly expressed by Escherichia coli BL21 (DE3), which encoded the extracellular protein of about 52 kDa. The extracellular activity of CelI15 from E. coli BL21 was up to about 6.78 U/ml, and all the other properties were almost the same as that from the wild-type strain.
一株产纤维素酶活力较高（2.82 U/ml）的新型细菌菌株被分离出来，通过形态特征和 16S rRNA 序列鉴定，将其命名为枯草芽孢杆菌菌株 I15。该菌株产生的胞外耐热纤维素酶在 60°C 和 pH 值为 6.0 时表现出最大活性。该酶非常稳定，在 65°C 孵育 2 小时后，仍保持超过 90%的原始 CMCase 活性。纤维素酶基因 celI15 被克隆并通过大肠杆菌 BL21（DE3）进行胞外表达，该基因编码约 52 kDa 的胞外蛋白。CelI15 的胞外活性高达约 6.78 U/ml，所有其他性质几乎与野生型菌株相同。
