食品科学 ›› 2013, Vol. 34 ›› Issue (5): 191-196.doi: 10.7506/spkx1002-6630-201305040

• 生物工程 • 上一篇    下一篇

产β-葡萄糖苷酶真菌的筛选鉴定、纯化及酶学性质分析

陈 静1,郝伟伟2,王春梅1,陈 惠1,*,吴 琦1,韩学易1   

  1. 1.四川农业大学生命科学与理学院,四川 雅安 625014;2.四川省华派生物制药有限公司,四川 简阳 641401
  • 收稿日期:2011-11-07 修回日期:2013-01-25 出版日期:2013-03-15 发布日期:2013-04-16
  • 通讯作者: 陈惠 E-mail:chen62hui@yahoo.com.cn

Screening and Identification of β-Glucosidase-Producing Fungi, and Purification and Enzymatic Analysis

CHEN Jing 1,HAO Wei-wei 2,WANG Chun-mei 1,CHEN Hui1,*,WU Qi 1,HAN Xue-yi1   

  1. 1. College of Life and Basic Sciences, Sichuan Agricultural University, Ya’an 625014, China; 2. HuaPai Biological Pharmaceutical Co. Ltd., Jianyang 641401, China
  • Received:2011-11-07 Revised:2013-01-25 Online:2013-03-15 Published:2013-04-16
  • Contact: CHEN Hui E-mail:chen62hui@yahoo.com.cn

摘要: 经刚果红平板染色法从土样中筛选到3株产纤维素酶的真菌,通过对其β-葡萄糖苷酶活力的测定,选择一株相对活力较高的菌株进行菌种鉴定。在形态鉴定的基础上,通过内转录间隔区(ITS)序列构建系统发育树初步鉴定为米曲霉(Aspergillus oryzae),命名为giF-10。对米曲霉giF-10进行摇瓶发酵,经硫酸铵沉淀、Sephadex G-100凝胶层析、DEAE Cellulose 52离子交换层析进行纯化。得到纯化后的β-葡萄糖苷酶,比活力为40.84U/mg,分子质量约90kD;该β-葡萄糖苷酶最适温度为55℃;在30~50℃之间热稳定性好;最适pH值为4.5;pH4.0~6.0稳定性好;金属离子对酶活力具有一定的影响,Mn2+对酶具有较强的激活作用;Fe3+和Cu2+对β-葡萄糖苷酶活力有较强的抑制作用;该酶对水杨素和纤维二糖具有较强的底物特异性;β-葡萄糖苷酶对水杨素的动力学参数:Km为0.676mmol/L;对纤维二糖的动力学参数为:Km为2.906mmol/L。

关键词: 米曲霉, β-葡萄糖苷酶, 纯化, 酶学性质

Abstract: Three cellulase-producing strains were screened from the soil sample and identified by Congo red method. A strain with the most powerful capability of producing β-glucosidase was also explored. The strain was identified as Aspergillus oryzae by morphological and ITS sequence analysis, and named as giF-10. Aspergillus oryzae giF-10 was fermented in shaking flask to obtain a great deal of β-glucosidase. Crude enzyme was purified by ammonium sulfate precipitation, Sephadex G-100 gel chromatography, and DEAE cellulose ion exchange chromatography. The specific activity of purified β-glucosidase was 40.84 U/mg. Molecular weight of β-glucosidase was approximately 90 kD as identified by SDS-PAGE. Its optimal temperature and pH were 55 ℃ and 4.5, respectively. It was stable at 30—50 ℃ and pH 4.0— 6.0. Different metal ions revealed different effects on β-glucosidase activity. Mn2+ could activate β-glucosidase while Fe3+ and Cu2+ could inhibit β-glucosidase. The enzyme showed stronger substrate specificity to salicin and cellobiose. Its Km for salicin and cellobiose were 0.676 mmol/L and 2.906 mmol/L, respectively.

Key words: Aspergillus oryzae, β-glucosidase, purification, enzymatic characteristics

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