Isolation and characterization of actinomycetes with antimicrobial activity from the soil and the effect of the environmental factors on their antimicrobial activity

This study aimed at isolating and characterizing antibiotic producing actinomycetes from a specific geographic location Alba’qa, Jordan, with a known soil character, and study the effect of the environmental factors on their antimicrobial activity, in order to relate the actinomycetes flora to the environmental characteristics. Soils of the Alba’qa region are of uniform composition and contain antimicrobial producing microorganisms. Although the initial aim was to isolate organisms of the genera Actinomyces, other organisms such as Aspergillus and other antibiotic producing microorganisms “mostly bacteria” were also isolated. Actinomycetes showed antimicrobial effect on all tested bacteria “Escherichia coli SQ21, Staphylococcus aureus SQ31, Streptococcus pyogenes SQ33, Serratia marcescens SQ22, Staphyloccocus epidermidis SQ32 and Bacillus spp. SQ41” depending on the media they were cultured on and the temperature they were incubated at. It was established that the optimum antibacterial activity is shown when cultivated on GYE medium at 30°C. This made a beneficial first step to find treatments for the diseases caused by the pathogenic bacteria.