Isolation and purification of antibacterial compound from Streptomyces levis collected from soil sample of north India

During the screening programme for microbial cultures producing antimicrobial agents, an active microbial strain of Streptomyces was isolated from the agricultural soil of Narnaul, Haryana India. Physiological, biochemical characteristics and 16S ribosomal RNA sequence homology studies revealed that it was similar to Streptomyces levis (sequence similarity 100%). The microbial strain was submitted to Genomebio Technologies Pvt. Ltd., Pune, Maharashtra, India under Accession No. EU124569. The isolated strain was found to produce extracellular active compound showing strong antimicrobial activity against Klebsiella pneumoniae MTCC 109, Pseudomonas aeruginosa MTCC 741 and Staphylococcus aureus MTCC 96. The antibacterial compound was successfully isolated and purified. Structure elucidation of antibacterial metabolite with EI-MS/ HRMS showed molecular ion peak at m/z 686 [M+H](+). Whereas, elemental analysis of the said compound showed C = 61.31, H = 8.61, N = 2.04 and O = 28.02, and indicated a molecular formula of C(35)H(59)NO(12). The presence of ‘chromone’ nucleus in the compound’s chemical structure was confirmed by using (1)HNMR studies. The present study reports the purification of potential antibacterial compound from Streptomyces levis isolated from the unexplored soil of north India and warrants for further characterization of this potential compound for optimum utilization for antimicrobial purposes.