Studies on a marine Streptomyces fradiae BW2-7 producing glycopeptide antibiotic Vancomycin effective against skin pathogens

A total of 124 marine actinomycetes were isolated from east and west coastal regions of Indian peninsula and assessed for its antimicrobial activity. A potent actinomycete isolated from west coast of India was selected by its antibacterial and antifungal activities and was identified as Streptomyces fradiae BW2-7 using 16S rRNA sequencing which produces antibacterial metabolite extracellularly and antifungal metabolite intracellularly under submerged fermentation conditions. Crude extract of the strain showed board antimicrobial activity spectra against the bacterial skin pathogens Staphylococcus aureus (25mm), Staphylococcus epidermidis (21mm) and fungal pathogen Trichophyton rubrum (15mm). Fermentation conditions for the production of antibiotic were optimized by using statistical method, Response Surface Methodology (RSM). Purified compound was subjected to structural elucidation. After medium optimization the antibiotics activity showed 8% improvement compared with unoptimized condition. The isolated compound MRK1 was found to be Vancomycin and showed effective against skin pathogens. This is the first report, where the compound was isolated from a new source S. fradiae and inhibiting the skin pathogens.