Characterization, classification genomic analysis and establishment of phylogenetic tree among local isolates of antibiotic producing streptomycetes.

During this study, 10 local Streptomyces isolates designated Zl, SH - 1, 8D, SL, ME - 18, NS - 38, AB - 38, IQ, LMS - 37 -3, and SH - 6 were characterized and classified. These local isolates were collected from different regions of Iraq. The study of these local isolates took different phases. The first phase was the determination of their growth requirements, differentiation, morphological and biochemical features. Results obtained showed that these streptomycetes were able to grow on all media used during the study. Their growth and differentiation differ depending on medium composition and Streptomyces species. Two of these local isolates designated ME -18, and LMS - 37 — 3 required complete set of mineral salts to accomplish complete maturation. All these isolates were found to prefer moderate pH ranging from 7 - 8 for growth, and incubation temperature of 28 - 37°C. None of them was found to be either thermophilic or psychrophilic organism. Streptomyces isolates when grown on rich medium were found to exhibit high variability which is a characteristics of streptomycetes except for local isolates designated NS - 38, and Zl that showed high stability among others suggesting that these two local isolates may have short hypervariable region or this region is stable one at the end of the chromosome. Cell wall analysis showed presence of diaminopiemilic acid, and mycolic acid in it's composition and absence of sugars like arabinose, galactose, madurose, and xylose that is a common feature of streptomycetes and suggested that the cell wall of type I. Morphological characteristics showed that 20% of local Streptomyces isolates have butyrous colonies, 60 % smooth colonies, and 20 % leathery in texture. Sporophore shapes were found to be Retinaculum - Apertum in 20% of streptomycetes, Rectusflixibilis in 50%, and 30 spira in the rest. Spore shape when detected showed to be spiny in 10% of the local Streptomyces isolates. 40% glabrous, 40% hirsute, and 10% verrucose. The second phase was to determine pigment formation. Results showed that 80% of the streptomycetes studied were able to produce diffusible pigment in the medium, 10% produced pH sensitive pigment. 30% were able to produce luminescent pigment, and 60% were melanin producers. Diffusible dyes detected were suggested to be of carotenoid type. The third phase was to investigate the ability of local Streptomyces isolates to produce antibacterial agents. Their ability to cease other microorganisms growth was tested against Gram -positive, Gram - negative, and eukaryotic cells. Results obtained showed that these streptomycetes were able to perform antimicrobial activity against test organisms suggesting presence of antibiotic - like product. TLC chromatography, IR and U. V spectroscopy showed that these isolates might be producers of chloramphenicol, neomycin, tetracycline, bleomycin, doxorubicin, and streptomycin. HPLC process showed the presence of bleomycin at concentration 22.19 - 33.54 ppm, tetracycline at concentration 0.57