Screening of rhizospheric actinobacteria isolated from different cultivated plants in Egypt

Abstract

In present study, four hundred and seventy-three actinobacterial isolates were isolated from five different rhizospheric soil samples including clover, potato, wheat, mint, and nalta jute plants. Culture characterization of all actinobacterial isolates was performed using starch casein agar medium. Microscopic examination of all isolates was carried out using slide culture technique. All isolates were identified morphologically. The most dominant actinobacteria isolated from rhizospheric soil was genus Streptomyces. The key factor of shaping microbial population in rhizosphere is plant species. Fifteen (3.1%) isolates only from all isolated actinobacteria were able to produce indole acetic acid. Out of fifteen actinobacteria, fourteen isolates belonged to genus Streptomyces, while the last one belonged to genus Saccharopolyspora. The fifteen actinobacteria could be used as plant growthpromoting rhizospheric bacteria instead of chemical fertilizers, since it enhances growth and development of plants through developing specific communication pathways with the plant and may influence plant physiology.