| 摘要: |
| 本研究从红树林沉积物样品中筛选获得一株具有较高纤维素酶活性的菌株ms-2，通过革兰氏染色、生理生化试验，以及16S rDNA基因片段比对鉴定该菌株为枯草芽孢杆菌（Bacillus subtilis） ms-2。对其产酶性质进行研究表明该菌株所产纤维素酶为胞外酶而非膜锚定酶，该酶具有良好的嗜热性，且在弱酸条件下酶活性较高，最适宜温度和pH分别为65 ℃和6.0，在此条件下最高酶活性为0.655 7U/cm3；另外，在浓度为1 mmol/dm3 Cu2+、Mg2+、Zn2+、Fe3+和Mn2+条件下，Cu2+对酶活性无显著影响，Mg2+、Zn2+、Fe3+ 和Mn2+ 对酶活性均有不同程度的抑制作用，其中Mn2+的抑制最为明显，酶活性下降了29.96%。由于产业应用中酶解纤维素时通常需要在55~60 ℃的温度下进行，研究获得的嗜热纤维素酶不仅适合这样的温度环境，还能维持较高的酶活性水平，并且对Cu2+、Mg2+、Zn2+、Fe3+较不敏感，有利于产业开发应用。 |
| 关键词: 海洋生物学 筛选 鉴定 枯草芽孢杆菌 纤维素酶 嗜热 |
| DOI：10.3969/J.ISSN.2095-4972.2020.03.006 |
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| 基金项目:海洋公益性行业科研专项资助项目（201405038）；中国APEC基金资助项目（OFWG032018S)；“十三五”厦门市海洋经济创新发展示范资助项目 (16CZP016SF13，16CZP017SF06)；自然资源部第三海洋研究所基本科研业务费资助项目(海三科2017027) |
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| Screening and activity analysis of thermophilic cellulase producing Bacillus sp. from mangrove sediments |
| HU Rui,SUN Xiao-hui,YANG Miao-sen,TANG Xu,XU Chang-an,JIA Ruo-kun |
| (School of Chemical Engineering, Northeast Electric Power University, Jilin 132000, China; Third Institute of Oceanography, MNR, Xiamen 361005, China) |
| Abstract: |
| In this study, the ms-2 strain with high cellulase activity was screened and identified from mangrove sediments samples. It is identified as a strain of Bacillus subtilis according to its morphological, physiological and biochemical characteristics and 16S rDNA sequencing result. The study on the enzyme producing properties found that the cellulase produced by the ms-2 strain was extracellular enzyme rather than membrane anchored enzyme. The enzyme presented good thermophilic activity and high activity in weak acid condition and produced the highest activity of 0.655 7 U/cm3 under the optimal conditions of 65 ℃ and pH 6.0. In addition, the enzyme activity showed no significant difference in 1 mmol/dm3 Cu2+, and significant inhibition in 1 mmol/dm3 Mg2+、Zn2+、Fe3+ and Mn2+, respectively. The enzyme activity was inhibited by 29.96% by Mn2+ while it showed more and less inhibition by Cu2+、Mg2+、Zn2+ and Fe3+, respectively. Enzymatic hydrolysis of cellulase in industrial applications usually needs to be carried out at 55-60 ℃. Thermophilic cellulase obtained not only is suitable in such temperature environment, but also can maintain a high level of enzyme activity. Moreover, the feature of less sensitive to Cu2+、Mg2+、Zn2+ and Fe3+ is favorable for the potential industrial application. |
| Key words: marine biology screening identification Bacillus subtilis cellulase thermophilic |
