289 International Journal of Pharmaceutical Sciences and Drug Research 2019; 11(6): 289-298 RESEARCH ARTICLE ISSN: 0975-248X CODEN (USA): IJPSPP Sand Dune Streptomyces JB66 Native to the Great Indian Thar Desert Inhibits Multidrug-Resistant Pathogens Jyotsna Begani 1 , Jyoti Lakhani 2 , Dharmesh Harwani 1* 1 Department of Microbiology, Maharaja Ganga Singh University, Bikaner-334001, Rajasthan, India 2 Department of Computer Science, Maharaja Ganga Singh University, Bikaner-334001, Rajasthan, India Copyright © 2019 Jyotsna Begani et al. This is an open access article distributed under the terms of the Creative Commons Attribution- NonCommercial-ShareAlike 4.0 International License which allows others to remix, tweak, and build upon the work non-commercially, as long as the author is credited and the new creations are licensed under the identical terms. ABSTRACT The efficacy of an actinomycete strain JB66 recovered from a sand dune soil from the Bikaner district of the Thar desert in inhibiting the growth of various bacterial pathogens was studied. The type strains Staphylococcus aureus, Shigella flexneri, Klebsiella pneumoniae and the clinical isolates Escherichia coli, multidrug-resistant S. aureus and P. vulgaris were included in the antimicrobial assays. Polyphasic characterization of JB66 isolate revealed its identity as Streptomyces (MH762010). It showed 88.99-89.24% sequence similarity with the other members of this genus and share the maximum (88.89%) similarity with Streptomyces sp. ATSC13. The strain JB66 was found to produce a high amount of extracellular L-asparaginase, catalase, gelatinase, protease, tyrosinase and urease enzymes. The partial chemical categorization of the methanolic crude extract of the JB66 strain led to the preliminary identification of various metabolic compounds. The thin-layer chromatography fractionation revealed the presence of prodigiosin pigment or chandramycin, cephalosporin or zeatin, daidzein, demethoxy rapamycin, 4,6-dihydroxy-7- methoxyisoflavone, munumbicins and amiclenomycin like compounds. Bio-autography revealed that the metabolites localized at the Rf values of 0.40, 0.46 and 0.53 in TLC profile had the actual bioactive fractions. UV-VIS spectrum absorbance maxima at 288 nm revealed the presence of an aromatic nucleus. Keywords: Actinomycetes, Thar desert, Sand dune, MDR, TLC, Rapamycin, Cephalosporin. DOI: 10.25004/IJPSDR.2019.110603 Int. J. Pharm. Sci. Drug Res. 2019; 11(6): 289-298 *Corresponding author: Dr. Dharmesh Harwani Address: Department of Microbiology, Maharaja Ganga Singh University, Bikaner-334001, Rajasthan, India Tel.: +91-8764131240 E-mail : dharmesh@mgsubikaner.ac.in Relevant conflicts of interest/financial disclosures: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. Received: 01 August, 2019; Revised: 30 October, 2019; Accepted: 12 November, 2019; Published: 30 November, 2019 INTRODUCTION Nature is a prolific source of many useful natural products that play many prominent roles in the development of new therapeutic agents. [1-3] A huge proportion of structurally different bioactive metabolites are synthesized by microorganisms to sustain in different ecosystems. [1, 4] Within microorganisms, actinobacteria represent the most promising group of bacteria that synthesize approximately two-thirds of all known natural bioactive products including some of the compounds most widely used as anticancer, anti-inflammatory, antibacterial, antifungal and antitumour agents etc. [5-16] Indeed, an estimated 70% or maybe more antibiotics