筛选碱性 CMCase 产生菌及其发酵条件的优化。
Screening of an Alkaline CMCase-Producing Strain and the Optimization of its Fermentation Condition.
机构信息
School of Forestry and Biotechnology, Zhejiang A&F University, Hangzhou 311300, China.
Institute of Botany, Jiangsu Province and Chinese Academy of Sciences, Nanjing, 210014, China.
出版信息
Curr Pharm Biotechnol. 2020;21(13):1304-1315. doi: 10.2174/1389201021666200129123818.
OBJECTIVE
Alkaline Carboxymethyl Cellulase (CMCase) is an attractive enzyme for the textile, laundry, pulp, and paper industries; however, commercial preparations with sufficient activity at alkaline conditions are scarce.
METHODS
High CMCase-producing bacterial isolate, SX9-4, was screened out from soil bacteria, which was identified as Flavobacterium sp. on the basis of 16S rDNA sequencing.
RESULTS
The optimum pH and temperature for CMCase reaction were 8.0 and 55°C, respectively. Alkaline CMCase was stable over wide pH (3.0-10.6) and temperature (25-55°C) ranges. Enzyme activity was significantly inhibited by the bivalent cations Mn and Cu, and was activated by Fe. To improve the alkaline CMCase production of SX9-4, fermentation parameters were selected through onefactor- at-a-time and further carried out by response surface methodologies based on a central composite design.
CONCLUSION
High CMCase production (57.18 U/mL) was achieved under the optimal conditions: 10.53 g/L carboxymethylcellulose sodium, 7.74 g/L glucose, 13.71 g/L peptone, and 5.27 g/L ammonium oxalate.
目的
碱性羧甲基纤维素酶（CMCase）是纺织、洗衣、制浆和造纸工业中极具吸引力的一种酶；然而，在碱性条件下具有足够活性的商业制剂却很少见。
方法
从土壤细菌中筛选出高 CMCase 产生菌 SX9-4，根据 16S rDNA 测序将其鉴定为黄杆菌属。
结果
CMCase 反应的最适 pH 值和温度分别为 8.0 和 55°C。碱性 CMCase 在较宽的 pH（3.0-10.6）和温度（25-55°C）范围内稳定。酶活性受到二价阳离子 Mn 和 Cu 的显著抑制，而被 Fe 激活。为了提高 SX9-4 的碱性 CMCase 产量，通过单因素实验选择发酵参数，并进一步通过基于中心组合设计的响应面法进行优化。
结论
在最佳条件下实现了高 CMCase 产量（57.18 U/mL）：羧甲基纤维素钠 10.53 g/L、葡萄糖 7.74 g/L、蛋白胨 13.71 g/L 和草酸铵 5.27 g/L。
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