白蚁肠道二株链霉菌株所产纤维素酶的分离、纯化和特征

食品科学 ›› 2012, Vol. 33 ›› Issue (17): 158-164.

白蚁肠道二株链霉菌株所产纤维素酶的分离、纯化和特征

霍光华1，黄小晖1，Shannon DILLON2，何刚强1，陈明辉1，龙昊知1

1.江西农业大学生物科学与工程学院 2. CSIRO Plant Industry, Clunies Ross Street, ACTON

收稿日期:2011-06-14 修回日期:2012-07-26 出版日期:2012-09-15 发布日期:2012-11-09
通讯作者: 霍光华 E-mail:hgh3813899@sohu.com

Isolation, Purification and Characterization of Cellulases from Streptomyces Strains in the Gut of the Termite Odontotermes formosanus

Huo GuangHua

Received:2011-06-14 Revised:2012-07-26 Online:2012-09-15 Published:2012-11-09
Contact: Huo GuangHua E-mail:hgh3813899@sohu.com

摘要/Abstract

摘要： 通过硫酸铵沉析、依次过葡聚糖G100和阴离子交换树脂DEAE葡聚糖A50柱，从白蚁(Odontotermes formosanus)肠道2株放线菌株发酵液中获得了1种葡聚糖外切酶(C1)、2种葡聚糖内切酶(CX)和1种β-葡萄糖苷酶(β-glucosidase，βG)。该2株放线菌株在形态、生长、生理生化特性上显示属于链霉菌属种类。SDS-PAGA电泳分析表明上述4种酶的分子质量分别为76.9、22.3、66.2、31.9kD。外切酶在pH 5.6，内切酶和β-葡萄糖苷酶在pH 5.0；以及内切酶和外切酶在50℃，β-葡萄糖苷酶在40℃时，有最大酶活性，甚至温度高达70℃时，这些酶仍有50%以上的酶活性。二价阳离子如Fe2+、Ca2+在质量浓度100mg/L条件下对酶有激活作用，而Mn2+、Cu2+、Zn2+、Co2+对酶活起抑制作用。结果表明来自白蚁肠道2株链霉菌株所产的纤维素酶可能以Fe2+和Ca2+作为辅基，属于酸性、耐热性酶。这类酶具备用于工业上分解不溶性的纤维素的能力。

关键词: 葡聚糖外切酶, 葡聚糖内切酶, β-葡萄糖苷酶, 链霉菌, 白蚁

Abstract: An exoglucanase (C1), two endoglucanases (Cx) and a β-glucosidase (βG) were isolated from the fermentation broth of two Actinomycete strains in the gut of the termite Odontotermes formosanus. These enzymes were purified sequentially by ammonium sulfate precipitation, and Sephadex G100 and DEAE-Sephadex A50 column chromatographies. Both Actinomycete strains were identified as belonging to Streptomyces spp. based on their morphological, growth, physiological and biochemical characteristics. The molecular masses of C1, two Cx enzymes and βG were determined by SDS-PAGE to be 76.9, 22.3, 66.2 kD and 31.9 kD, respectively. The optimal pH was 5.6 for C1 and 5.0 for Cx and βG, respectively; the optimal reaction temperature was 50 ℃ for Cx and C1, and 40 ℃ for βG, respectively. Moreover, these enzymes retained more than 50% activity even at a temperature as high as 70 ℃. These enzymes could be activated by Fe2+ and Ca2+, but inhibited by Mn2+, Cu2+, Zn2+ and Co2+. These results indicate that these cellulases originated from Streptomyce strains in O. formosanus gut are acidic, heat-tolerant enzymes and that their prosthetic groups may be Fe2+ and Ca2+. Therefore, these enzymes has potential in industrial applications for the decomposition of insoluble cellulose.

Key words: exoglucanase, endoglucanase, β-glucosidase, Streptomyces, Odontotermes formosanus

霍光华1，黄小晖1，Shannon DILLON2，何刚强1，陈明辉1，龙昊知1. 白蚁肠道二株链霉菌株所产纤维素酶的分离、纯化和特征[J]. 食品科学, 2012, 33(17): 158-164.

Huo GuangHua. Isolation, Purification and Characterization of Cellulases from Streptomyces Strains in the Gut of the Termite Odontotermes formosanus[J]. FOOD SCIENCE, 2012, 33(17): 158-164.

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