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

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.

Key words:Streptomyces rameus, 16S rRNA, Identification, Xylanase