Genotypic Identification of Bacterial Communities in a pretreated sample of Tigris River sediment

Abstract

Streptomyces bacteria have a complex secondary metabolism, producing over two-thirds of the natural origin antibiotics. They reside in soil and river sediment environment and interact with other microorganisms, but little is known on their effects in soil microbial community. Studies reported that many bacterial strains affect soil microbial community. In this study, a soil microbial community was screened to identify the most prominent bacteria associated with Streptomyces by using the same culturing conditions. Tigris river sediment soil samples pretreated by heating and cultured in supplemented IPS4 media with NaCl and Tetracycline and Nystatin. Out of 5 samples, three Afipia spp., and one Sphingomonas genosp were isolated and confirmed by PCR using universal 16S rDNAs primer pair and partial sequencing, in addition to Streptomyces azureus. Phylogenetic along with the sequences of closely related reference organisms showed the distance between the tested isolates. This finding showed the constituents of bacterial species in soil community under the same condition with Streptomyces, which is a promising source of biocontrol agents and how Streptomyces affect soil microbial community.