BETA-GLUCOSIDASE SYSTEM OF NEUROSPORA CRASSA .I. BETA-GLUCOSIDASE + CELLULASE ACTIVITIES OF MUTANT + WILD-TYPE STRAINS
BETA-GLUCOSIDASE SYSTEM OF NEUROSPORA CRASSA .I. BETA-GLUCOSIDASE + CELLULASE ACTIVITIES OF MUTANT + WILD-TYPE STRAINS
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DOI：
10.1128/jb.87.4.761-770.1964
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发表时间：
1964-01-01
影响因子：
3.2
通讯作者：
CHASE, LR
中科院分区：
文献类型：
--
作者：
EBERHART, B;CROSS, DF;CHASE, LR
本文分离了一株粗神经孢子菌（Neurospora crassa）的突变株葡萄糖-1，其[β]-葡萄糖苷酶活性较低。通过检测辐照菌落的胞外[β]-葡萄糖苷酶活性来选择突变体。含有葡萄糖-1基因的菌株在其生长培养基中破坏内皮素的能力也明显降低。突变菌株以野生型速度生长，以纤维素二糖或羧甲基纤维素为碳源。这种与野生型的营养缺陷相似性可以通过神经孢子菌中存在至少两种互补的[β]-葡萄糖苷酶（可能还有两种纤维素酶）来解释。在60℃下孵育1分钟后，可耐热的[β]-葡萄糖苷酶被破坏。这种酶存在于菌丝中，但在分生孢子提取物中不存在。第二种[β]-葡萄糖苷酶在60℃下相对稳定，存在于菌丝和分生孢子中。用葡萄糖-1和野生型菌株的菌丝提取物的铵分离实现了这些酶的部分分离。耐热性[β]-葡萄糖苷酶和纤维素活性似乎不受葡萄糖-1突变的影响，而耐热性葡萄糖苷酶在葡萄糖-1菌株中大大降低。
A mutant strain, gluc-1, of Neurospora crassa was isolated and characterized by its low level of [beta]-glucosidase activity. The mutant was selected by testing irradiated colonies for extracellular [beta]-glucosidase activity. Strains containing the gluc-1 gene were also visibly detected by their reduced ability to destroy esculin in their growth media. The mutant strain grew at wild-type rates with cellobiose or carboxymethylcellulose as carbon sources. This auxotrophic similarity with wild type is explained by the presence of at least two [beta]-glucosidases (and possibly two cellulases) in Neurospora that act complementarily. The thermolabile [beta]-glucosidase was destroyed after 1 min of incubation at 60 C. This enzyme was present in mycelia but absent in conidial extracts. A second [beta]-glucosidase that is comparatively stable at 60 C was present in both mycelia and conidia. A partial separation of these enzymes was achieved with ammonium fractionation of mycelial extracts of gluc-1 and wild-type strains. Thermolabile [beta]-glucosidase and cellulose activity appear not to be affected by the gluc-1 mutation, whereas the thermostable glucosidase is greatly reduced in gluc-1 strains.