Ecology and biodiversity profile of the Genus Streptomyces in the soil of the State of Qatar

Abstract

Ecology and biodiversity profile of Streptomyces in the soil of Qatar have been studied in 123 soil samples from different sites distributed all over the country. Moisture contents of soils samples ranged between 0.2-8.8% (w/w) and pH values tended to be of the alkaline type (7.6-9). Electric conductivity (25-40.1 ms) was recorded with the highest values for sites 13, 18, 22, 50, 40 and a narrow range (0.2-7.8 ms) for the remaining sites. The total bacterial count between (1.2 x 10^4)-(29 x 10^4) c.f.u/g of dry soil, whereas the Streptomyces count had a narrow range of (1 x 10^4)-(12 x 10^4) c.f.u/g of dry soil. The morphology of the isolated Streptomyces had a common form of colony; they were mainly spherical, smooth, elevated with diameter range between 1-5 mm with only a few exceptions. Thirty four of the isolates identified based on the phenotypic and chemotacxonomic characteristics, belongs to the genus Streptomyces strains showed that 42.4% and 18.2% were white or grey color respectively, whereas the remaining strains showed variation in color including transparent, black, orange and pink. Moreover, the white and orange colored strains were conspicuous in the northern part of the country (sites 1-44) whereas the transparent strains were predominant in the southern part (sites 45-85). However, strains colored grey, black or brown appeared to be restricted to the midland (sites 56-65). This preliminary study represents the first about Streptomyces in Qatari soils as far as we know.