Shandong Provincial Key Laboratory of Applied Mycology, College of Life Sciences, Qingdao Agricultural University, Qingdao 266109, China.
Appl Biochem Biotechnol. 2012 Oct;168(3):550-67. doi: 10.1007/s12010-012-9796-3. Epub 2012 Jul 13.
Cellulases which are active and stable under extreme conditions have attracted considerable attention because of their potential industrial applications. Marinimicrobium sp. LS-A18 showed high extracellular carboxymethylcellulase (CMCase) activity when grown on mineral salt medium containing carboxymethylcellulose as the sole carbon source. Maximum CMCase activity was obtained at 55°C and pH 7.0 in the absence of NaCl. Under the optimized fermentation conditions, the yield of CMCase was increased up to 2.5 U/ml, which was 3.1-fold higher than that before optimization. The enzyme retained 84 % of residual activity after incubation at 60°C for 1 h and more than 88 % of residual activity after incubation for 72 h in the presence of different pH (5-11) and NaCl concentrations (0-25 %, w/v), indicating it was halotolerant, thermostable and alkali-stable. These characteristics made the CMCase from Marinimicrobium sp. LS-A18 as a potentially novel biocatalyst in biotechnological and industrial applications.
由于其潜在的工业应用，在极端条件下具有活性和稳定性的纤维素酶引起了相当大的关注。海洋微菌（Marinimicrobium）sp. LS-A18 在含有羧甲基纤维素作为唯一碳源的无机盐培养基中生长时，表现出较高的胞外羧甲基纤维素酶（CMCase）活性。在无 NaCl 的情况下，55°C 和 pH 7.0 时可获得最大 CMCase 活性。在优化的发酵条件下，CMCase 的产量提高到 2.5 U/ml，比优化前提高了 3.1 倍。该酶在 60°C 孵育 1 小时后保留了 84%的残余活性，在存在不同 pH（5-11）和 NaCl 浓度（0-25%，w/v）的情况下孵育 72 小时后保留了超过 88%的残余活性，表明其具有耐盐性、热稳定性和碱稳定性。这些特性使海洋微菌（Marinimicrobium）sp. LS-A18 的 CMCase 成为生物技术和工业应用中一种有潜力的新型生物催化剂。
