Streptomyces are soil dwelling, Gram positive, filamentous bacteria belonging to the phylum Actinobacteria. These are high G+C organisms noted for their characteristic ‘earthy’ odour which results from production of a volatile metabolite, geosmin. Streptomyces are known for their ability to produce antibiotics. In fact, two thirds of the known antibiotics are produced by actinomycetes and 80% of them are made by members of Streptomyces genus.

An actinomycete strain, designated SSB, was isolated from the local soil sample. Initial studies indicated that it was a Streptomycete. It was sent to IMTECH, Chandigarh for further identification. On the basis of morphological, phenotypic and biochemical characteristics, it was identified as Streptomyces torulosus, SSB. The strain SSB was found to produce a reddish pigment on both solid as well as liquid media. The pigment production was best observed in Potato dextrose broth (Hi-media) and hence used for further studies on pigment production. Streptomyces torulosus is not reported earlier to produce such a pigment. The pigment produced by the strain SSB was extracted in ethyl acetate and purified by standard chromatographic techniques. The absorption spectra of the partially purified pigment were determined. It was found to be similar to Actinomycin-D. The partially purified pigment was found to have antibacterial activity against gram positive organisms.