Therapeutic Applications and Biological Activities of Secondary Metabolites Isolated from Pseudomonas species

Abstract

Soil bacteria are the necessary part of the soil ecosystem and they are involved in organic matter mineralization, biogeochemical cycles of nitrogen and carbon, and their distribution can be changed by litter quality. Soil samples were acquired from different locations of district Peshawar. To isolate Pseudomonas species serial dilution of the samples were performed by using Nutrient agar medium . Each dilution was added to sterile plates aseptically and the plates were incubated at 37°C for 24 hours followed by sub-culturing. A combination of technique, including colony morphological evaluation, gram staining and biochemical testing were used to identify isolated bacterial colonies after incubation. The antimicrobial activity of Pseudomonas species were subjected to primary screening against various test organisms (Escherichia coli, Staphylococcus aureus and Klebsiella pneumoniae). During the antibacterial activity at 75µl concentrations of secondary metabolites, 11mm, 13mm and 19mm zones were made against S. aureus, Klebsiella, and E. coli respectively. At 100 µl concentration secondary metabolites showed 15mm,17mm and 24mm zones against S. aureus, Klebsiella spp. and E. coli respectively. The secondary metabolites of pseudomonas spp were tested for its phytotoxic activity against Lemna minor. (Metabolites did not show any phytotoxic activity). Insecticidal activity of the metabolites was performed on Black Garden ant (Rhyzopertha dominica and Tribolium castaneum).  A total of 50 ants were used in this test. It was concluded from our study that Pseudomonas spp isolated from different locations of district Peshawar has antagonistic ability to inhibit growth of different pathogenic bacteria.