Profiling of red pigment produced by Streptomyces sp. JAR6 and its bioactivity

Actinomycetes strain was isolated from leaf litter soil sample and was identified as Streptomyces sp. by conventional and molecular approaches. The biologically active compound responsible for antimicrobial and anticancer activity of the strain JAR6 was elucidated by solid state fermentation followed by subsequent chromatographic and spectroscopic analysis. Extraction, purification and structural confirmation of red pigment metabolite viz undecylprodigiosin were established on the basis of spectroscopic studies and comparing the data from the literature. The biologically active compound was tested against Gram-positive and Gram-negative clinical isolates and its minimum inhibitory concentration was recorded. The antimicrobial activity of undecylprodigiosin is more prominent against Salmonella sp., Proteus mirabilis, Shigella sp. and Enterococcus sp. whereas, it was less effective against Staphylococcus aureus, Klebsiella pneumonia and Escherichia coli. The anticancer activity of undecylprodigiosin was tested against HeLa cell lines and it exhibited commendable cytotoxicity effect with IC₅₀ value of 145 µg/ml. The present investigation reveals that undecylprodigiosin produced by Streptomyces strain JAR6 is a potent bioactive metabolite with effective pharmaceutical properties.