Four Streptomyces spp. isolates from rhizosphere soils showing somaclonal variation were screened of morphological, antimicrobial, pigment, pectinase activity, isozymes and DNA-fingerprint. Based on visual observation by light and electron microscopes of four Streptomyces isolates were identified as St. scab, St. viridiviolaceus, St. capillispirales and St. refuineus. They showed different in mycelium and conidia spores as well as variable diffusible pigment in experimental medium. All isolates showed antimicrobial potentialities against tested microbial. The extend of antibiosis, the isolates were differed against microbial that exhibited a strong activity against +VG bacteria, yeast, a weak activity against -VG bacteria and fungi. DISC-PAGE of pectinase activity and isozymes appeared differences among four isolates in number and density 5, 5, 4, 5 isozymes of Streptomycetes isolates, respectively. DNA-finger printing was used for molecular analysis of somaclonal variation among four Streptomycetes isolates. Only three arbitrary primers (among ten tested) were chosen as producing polymorphic DNA fragments differentiating of four isolates. RAPD-PCR revealed polymorphism among four isolates, 2 polymorphic fragments (specific fragments) with 12.5%; 8 monomorphic fragments (common fragments) with 50% and revealed 6 unique fragments (genetic marker) with 37.5% (1327, 1018, 950 and 250 bp) of St. scab, (200 bp) of St. viridiviolaceus, (575bp) of St. capillispirales and (350 bp) of St. refuineus. The results showed that, the somaclonal variation among four Streptomycetes isolates are close similarity within Streptomycetal group depending on genetic variability.
Streptomyces spp., Biodiversity, pectinase, RAPD-PCR, DISC-PAGE
© The Author(s) 2015. Open Access. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License which permits unrestricted use, sharing, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.