Isolation and Screening of Antibiotics Producing Streptomyces spp from the Soil Collected around the Root of Alnus nepalensis from Godawari

Actinomycetes are considered as the most invaluable prokaryotes whose genome mining show a great number of putative secondary metabolite biosynthesis pathways as well as gene clusters ranging from 20 to 50 per genome. The genus Streptomyces has been explored for its ability to produce 60% antibiotics worldwide. Alnus nepalensis (Alder) has been found to harbor diverse Eubacteria in its rhizosphere. To evaluate the antibiotic production potential from Actinomycetes, we collected soil samples from rhizosphere (5-7 cm deep) of Alder tree. Primary screening was done by cross-streak method against Multidrug Resistant (MDR) such as Methicillin resistant Staphylococcus auereus (MRSA), Vancomycin resistant Enterococcus feacalis (VRE), Imepenem resistant Acinetobacterbaumannii, Vancomycin resistant Klebsiella pneumonia and Imepenem resistant E. coli as well as Non-MDRs (E. coli, Bacillus subtilis, Klebsiella pneumoniae, S. aeureu and Enterococcus feacalis). Extraction of antibiotics was done using rota-vapour from extract obtained by solid-substrate fermentation technique followed by solvent extraction. Secondary screening was done using well diffusion assay against MDRs. Among total of 40 isolates of Actinomycetes recovered, 14 showed remarkable zone of inhibition (ZOI) to various MDRs. NASA 303 showed 26 mm of ZOI against VRE, NASA 101 had ZOI of 34 mm against MRSA, NASA 319 had 33.7 mm ZOI against Imepenem resistant E. coli, NASA 306 had 36 mm of ZOI against Vancomycin resistant Klebsiella pneumoniae, and NASA 108 showed ZOI of 29.6 mm against Imepenem resistant E. faecalis. This investigation revealed that the Actinomycetes found in Rhizosphere of Alder tree had MDR killing potent antibiotics, which needs to be further explored

Comparative Antioxidant, Antimicrobial and Phytochemical Assesments of Leaves of Desmostachya bipinnata L. Stapf, Hordeum vulgare L. and Drepanostachyum falcatum (Nees) Keng f.

 Nepal is rich in varieties of religious plants. The locally used religious plants also carry medicinal importance. Desmostachya bipinnata L. Stapf, Hordeum vulgare L. and Drepanostachyum falcatum (Nees) Keng f. are three plants belonging to the family Poaceae having religious significance in different practices of Hinduism. They were also used as traditional medicines by our ancestors but nowadays they are underutilized. In this research, our core objective was to validate the traditional assumption of use of these plants in medicinal purposes by carrying out the assessments like antimicrobial assessment, antioxidative assessment and phytochemical assessment. Methanolic extracts produced from leaves of all three plants were examined for antimicrobial activities through agar well diffusion method. The same extracts were also assessed for determining their antioxidative potentials with the use of DPPH (1, 1-diphenyl-2-picryl hydrazyl) free radical scavenging assay followed by qualitative phytochemical analysis and GCMS (Gas Chromatography Mass Spectroscopy). Most promising antimicrobial activity was shown by Desmostachya bipinnata L. against Salmonella typhimurium and Staphylococcus aureus, Drepanostachyum falcatum (Nees) Keng f. against Salmonella typhimurium and Klebsiella pneumoniae and Hordeum vulgare L. against Salmonella typhmurium and Staphylococcus aureus. The antioxidant activity of the plant extracts were observed in descending order of Hordeum vulgare L.>Desmotachya bipinnata L. > Drepanostachyum falcatum (Nees) keng f. and phytochemical assessment of the extracts indicated the presence of alkaloids, glycosides, sterols, Triterpenes, Saponins, Flavonoids, Coumarins, Phlobatanin and reducing sugars. Through this project, we can clarify that the above mentioned plants have bioactive compounds which contributed for the presence of antimicrobial and antioxidative property in the plants