Browsing by Subject "Actinomycetes"
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Item SCREENING OF POTENTIAL ANTIBIOTIC PRODUCING ACTINOMYCETES EXTRACTED FROM SOIL AND WATER SAMPLES FROM DIFFERENT REGIONS OF KATHMANDU VALLEY(Amrit Campus, 2022-08-08) Sardar, Chandra KishoreActinomycetes are Gram-positive, aerobic spore forming bacteria that are characterized by aerial and mycelial growth and are chief antibiotic producers. The aim of this study was to screen antibiotic producing actinomycetes and determine its antibiotic activity against ATCC cultures. A total of 60 samples (30 water and 30 soil) were collected from different regions of Kathmandu Valley viz. Kathmandu, Lalitpur and Bhaktapur spanning from the month of March 2022 to May 2022. Spread plate technique was employed to isolate the actinomycetes on Starch M-Protein Agar, and primary and secondary screening techniques were performed via Perpendicular Streak method and Agar-well diffusion respectively for screening their ability to produce antibiotics. The actinomycetes were confirmed by the macro and microscopic examination, biochemical and physiological tests. The crude extract obtained from the submerged state fermentation was filtered and centrifuged; tested against the Standard cultures viz; Staphylococcus aureus ATCC 43300, Escherichia coli ATCC 35218, Escherichia coli ATCC 25922 and Klebsiella spp. ATCC 700603 via agar well diffusion method. Out of the 28 (93.3%) isolates obtained from 30 soil samples, only two isolates (7.3%) i.e., NP1 and MI4 showed antimicrobial activity against the ATCC cultures which were presumed to be Streptomyces. No actinomycetes were obtained from water samples. ANOVA revealed no significant difference at 5% level of significance (0.535; P>0.05) between the standard streptomycin (100 µg/ml) and NP1.The soil of Kathmandu Valley harbors microbial diversity that encompasses potential antimicrobial producing actinomycetes which in turn can help in booming the economy by enabling the production of indigenous antibiotics.Item Study on Antimicrobial Activities of Actinomycetes Isolated From Soils of Different Parts of Khumbu Region(Department of Microbiology, 2007) Koirala, JunuThe present study has been carried out at the laboratory of National Academy scienceand Technogy between 2006 October to 2007 September. The soil samples (N=4) collected from different places of ‘Khumbu’ region, Nepal(2500-5050m altitude) were processed to isolate antif ungal and antibacterial Actinomycetes. Altogether 22 isolates of Actinomycetes were isolated. In all isolates, 18 isolates were identified to genus level of which 11 isolates belonged to genus Streptomyces, three isolates belonged to Micromonospora, and two isolates belonged to Nocardia and one each belonging to Actinomadura and Strep to verticillium. All the eighteen isolates were screened for their antimicrobial activities against targetcultures viz; plant pathogenic fungi:Alternariaspp., Fusarium oxysporum, Fusariummoniliforme,Geotricum spp., Gloeosporium sporioides, Helminthosporium spp. andSclerotinia spp. and bacterial pathogens: Bacillus subtilis, Staphylococcus aureus,Enterobacter spp., Escherichia coli, Klebsiella pneumoniae, Proteus vulgaris,Pseudomonas aeruginosa, Citrobacterspp.,SalmonellaparatyphiAand Shigellaspp. In all Actinomycetes isolates, 14 isolates which showed antimicrobial activity, 5isolates showed activity only against gram positive bacteria while 5 showed broad hostrange showing activity against both gram positive and gram negative bacteria. However, only two isolates X1 and C4 belonging to Streptomyces spp. were activeagainst all the target fungal cultures. Out of all potential antifungal and antibacterial isolates, X1 and C4 and one isolate Ch9belonging to Actinomadura spp. were chosen for the antimicrobial compoundproduction and extraction of bioactive compound. The fermentation was carried out for 21 days using starch casein broth and the cell freesupernatant was subjected for solvent extraction. The extracted residue also showedbroad spectrum antibacterial and antifungal activity against target organisms. The bioactive residues (crude extracts) were dissolved in chloroform and run in silicagel precoates separately using chloroform: methanol (40:1) as the solvent system. Thecrude extract of isolate X1 gave two spots having R 0.58 and 0.66 and that of Ch9 andC4 each gave single spot having R f vi f 0.79 and 0.66 respectively. Key words: Actinomycetes, Antimicrobial activities, bioactive secondary metabolite,Khumbu,Streptomycesspp.