Molecular identification of streptomycetes by exploiting RNA polymerase beta-subunit (rpoB) gene in Saudi arabia

This study was designed with the aim of exploring the efficacy of RNA polymerase beta subunit, rpoB gene analysis for the identification of streptomycetes. A characteristic marine environment distinguished by their content of streptomycetes were targeted, and two organisms of the genus Streptomyces were isolated in Saudi Arabia. The two Streptomyces spp., named isolates EH1 and EH2 were isolated and subjected to the regular phenotypic characterization including morphological and physiological studies, analyses of cells hydrolysates, detecting their antibacterial activities and pocks formation ability. These isolates showed inhibitory activity of gram-positive bacteria Staphylococcus aureus and Bacillus subtilis. The two isolates gave positive results in pocks formation test, which indicated that both must belong to the genus Streptomyces. Molecular identification of both isolates was accomplished through analysis of the beta-subunit of the RNA polymerase gene (rpoB) to assist in species identification. The target fragments 352 bp were amplified and detected in both isolates using agarose gel electrophoresis, indicating that they belong to the genus Streptomyces. The amplified product of the isolate EH1 was sequenced and 296 bp continuous sequence was determined (GenBank accession MK569762.1). By matching the obtained sequence with the Streptomyces DNA sequence databases, the isolate EH1 was found very similar to Streptomyces labedae. The study concluded with the possibility of using molecular analysis of RNA polymerase beta subunit gene to correctly identify streptomycetes to the species level.