Nidhi Srivastava, Sanjay Gupta and Indira P. Sarethy* Pages 207 - 220 ( 14 )
Background: Multi-drug resistance among pathogens is emerging due to the slow pace of development of new antimicrobials by combinatorial chemistry. Natural products from microorganisms obtained from under-explored habitats can be lead molecules for such discoveries. In search of new antimicrobial compounds, Streptomyces isolate UK-201 exhibiting broad-spectrum antimicrobial and antifungal activity, obtained from under-explored Lachhiwala Reserve forest, of the Himalayas was selected in this study.Objectives: The major objectives were to characterize isolate UK-201, taxonomically identify it based on 16S rDNA sequencing and execute metabolite fingerprinting of ethyl acetate extract of UK-201 by GC-MS. Methods: Isolate UK-201 was characterized by phenotypic, biochemical/physiological methods and identified by 16S rDNA sequencing. Ethyl acetate extract of this isolate exhibited antimicrobial activity against the selected panel of gram-positive, gram-negative bacteria and fungi. The extract was partially purified by column chromatography. Active fractions were pooled and analysed by GCMS. The obtained compounds were tentatively identified by collated data analysis based on Similarity Index, and observed and calculated Retention Indices. Results: Isolate UK-201 showed 97.46% similarity to Streptomyces niveiscabiei, 96.88% to S. sasae and S. puniciscabiei, 96.72% to S. capoamus and S. yaanensis. A low similarity percentage indicated the taxonomic novelty of the isolate and was confirmed by comparing it with phenotypic characteristics with the nearest matches. Metabolite fingerprinting showed the presence of twenty-four novel compounds. Conclusion: This study showed that bioprospection from under-explored habitats conferred novel bio and chemodiversity.
Streptomyces, 16SrDNA sequencing, antimicrobial, metabolite fingerprinting, GC-MS.
Department of Biotechnology, Jaypee Institute of Information Technology, A-10, Sector-62, Noida-201307, Department of Biotechnology, Jaypee Institute of Information Technology, A-10, Sector-62, Noida-201307, Department of Biotechnology, Jaypee Institute of Information Technology, A-10, Sector-62, Noida-201307