Streptomyces Waksman and Henrici (1943) species and their applications anti-pathogenic bacteria and study its compatibility with plant extracts

Abstract

Twelve samples were collected from Baghdad city. From 12 samples, 17 colonies were obtained. Out of the 17 Actinomycetes colonies. sub-cultured on ISP2 for growth, and incubation of plates for 7 days, only three isolates demonstrated cultural characteristics similar to that of Streptomyces sp. three isolates were selected and purified by pure culture techniques of Streptomyces sp. All isolates were given a number as B1, B2, and B3. All Streptomyces sp isolates were screened for their antibacterial activity on Yeast extract-malt extract agar medium (ISP2) using scross-streak technique against two pathogenic bacteria include Gram-negative (Two pathogenic bacteria, including Gram-negative (Pseudomonas aeruginosa) and Gram-positive (Staphylococcus aureus). Among three Streptomyces sp isolates that obtained from Baghdad city (Al-Jadriya), one isolates (B2) didn’t show any antibacterial activity against any type of pathogenic bacteria (Gram-negative and Gram-positive bacteria), while two Streptomyces sp isolates (B1 and B3) showed antibacterial activity against Gram-negative (Pseudomonas aeruginosa) and Gram-positive (Staphylococcus aureus. Screening was performed by Agar-Well Diffusion method and growth inhibition zones were measured in millimeters for each of the Streptomyces isolates (B1 and B3). Tested isolates have shown potent in vitro antibacterial activities against all tested pathogens. The highest activities were shown by isolate B1 against S. aureus 19.5 mm, Pseudomonas aeruginosa 14 mm. It is also evident that B3 isolate have shown activities against all pathogenic bacteria with inhibition zone diameters ranging between 17 and 13 mm against S. aureus and Pseudomonas aeruginosa respectively. Effect of Pomegranate peel and Matricaria chamomilla extracts (200μl, 300μl and 400μl) on the growth of Streptomyces sp were initially determined by the agar well-diffusion method, showed there is no diameters of inhibition zones exerted by the extract towards Streptomyces in different concentrations of Pomegranate peel and Matricaria chamomilla extracts.