Isolation of three xylanase-producing strains of actinomycetes and their identification using molecular methods.

Eighty-eight actinomycetes were isolated from 20 samples collected from different locations in and around Delhi, India. Among these, 69 isolates were found positive for xylanase production. Of 69 isolates, 3 (SN32, SN77, and SN83) produced >125 IU/ml xylanase. Modern genetic tools were used for revealing the identities of these potent xylanase producers. The selected isolates were categorized under the genus Streptomyces based on their cultural and morphologic characteristics. Genetic diversity among these species of Streptomyces was established based on restriction length fragment polymorphism and random amplified polymorphic DNA analysis. The closest phylogenetic neighbours according to the 16S rRNA gene-sequence data for the three isolates SN32, SN77, and SN83 were Streptomyces cyaneus, S. tendae, and S. caelestis, respectively.