一株高产木聚糖酶的枝链霉菌的分离鉴定及产酶

Isolation, Indentification of a Streptomyces rameus Strain with High Level Xylanase Activity and Its Enzyme Production

摘要:

对1株高产木聚糖酶的链霉菌进行了鉴定并研究其木聚糖酶的生产过程及水解产物特点。分离得到1株产木聚糖酶的链霉菌Streptomyces sp. L2001, 从形态学特征、培养特征和生理生化特征等方面对该菌株进行了鉴定。PCR扩增得到16S rDNA序列全长为1429 bp, 分析结果表明, 菌株与Streptomyces rameus NBRC3782同源性达99.16%。结合传统生理生化实验结果鉴定为枝链霉菌。菌株液体发酵6 d能产生842.0 U/mL木聚糖酶活力。经HPLC分析酶解产物, 结果显示木二糖、木三糖及木四糖含量之和高达93.5%, 该酶适用于工业化生产低聚木糖。

Abstract:

A Streptomyces rameus strain with high yeild in xylanase activity was identified. Its capacity to produce xylanase and the characteristics of its hydrolysates were also investigated. A new strain of Streptomyces sp. L2001 was isolated from soil samples and was identified using morphological, cultural, physiological and biochemical characterisctics. The total length of 16S rDNA fragment was 1429 bp through PCR amplification. Our results showed that 16S rRNA sequence of Streptomyces sp. L2001 homologied up to 99.16% with that of Streptomyces rameus NBRC3782. Combining the traditional characteristics from physiological and biochemical tests, the strain L2001 was identified as Streptomyces rameus. As the firstly-reported strain to be capable of producing xylanase, its maximal yield could reach to 842.0 U/mL within 6 days’ cultivation under submerged fermentation condition. Using HPLC analysis, the total contents of xylobiose, xylotriose and xylotetraose constituted 93.5% of the hydrolysates of the xylanase from Streptomyces sp. L2001. Our results suggested that the xylanase is applicable to industrial production of functional xylo-oligosaccharides.