1株产木聚糖酶菌株的鉴定、产酶条件的优化及酶学性质初探

Identification of A Xylanase-producing Bacterial Strain,Optimization of Its Xylanase-producing Conditions,and Properties of Produced Xylanase

以木聚糖为唯一碳源,从腐败的甘蔗叶中分离木聚糖降解菌,结合木聚糖水解圈法及胞外酶活测定(DNS)法筛选到1株高产木聚糖酶的菌株ZJ-1。16S rRNA序列及系统发育分析结果表明ZJ-1菌株与链霉菌(登录号:KC856931.1)处于同一最小分支,且与多株链霉菌属菌株的相似性均达到98%以上,故将菌株ZJ-1初步鉴定为链霉菌(Streptomyces sp.ZJ-1)。在最适产酶条件(碳源CMC-Na、氮源蛋白胨、初始培养p H 6.5~10.0、培养温度25℃、连续培养6 d)下,ZJ-1所产木聚糖酶的活性达40.0 U/m L。ZJ-1所产木聚糖酶的最适反应温度为60℃,最适反应p H值为6.0。

A novel bacterial strain ZJ-1 producing xylanase was isolated from the decomposed sugarcane leaves by using the methods of xylanase-hydrolyzing ring and extracellular enzymatic activity determination. The Blast of the 16 S rRNA fragment in Gen Bank and the phylogenetic tree analysis indicated that the homology of ZJ-1 with Streptomyces sp.（accession number：KC856931.1） was more than 98%. Therefore,ZJ-1 was identified as Streptomyces sp. ZJ-1. Under the optimum xylanase-producing conditions（using CMC-Na as carbon source,using peptone as nitrogen source,p H 6.5 ~ 10.0 for initial culture,culture for 6 days at 25 ℃）,the activity of xylanase produced by ZJ-1 reached 40.0 U/m L. The optimum reaction temperature and reaction p H-value for the produced xylanase were 60 ℃ and 6.0,respectively.