Screening, isolation and purification of antibacterial agents from marine actinomycetes (original) (raw)

2012, International Current Pharmaceutical Journal

As marine environmental conditions are extremely different from terrestrial ones, it is surmised that marine actinomycetes might produce novel bioactive compounds. Hence marine sediments, collected from the coastal areas of Gokharna and Muradeshwara of Karnataka state, were screened Seventeen isolates were obtained on starch-casein agar media by soil dilution technique. However, only six isolates namely ACT-A2, ACT-A3, ACT-A4, ACT-A5, ACT-A7 and ACT-A15 showed significant antibacterial activity against both gram-positive and gram-negative bacteria. Morphological, cultural and biochemical characterization indicated that the isolates belong to Streptomyces genus of Actinomycetes. Further studies were carried out with the most active ACT-A2. Optimization of media, temperature and pH by shake flask fermentation indicated starch-casein, 28°C and 7 to be suitable for ACT-A2. The production of antibiotics began after 24 h, reached maximum at 72 h and maintained at the same level up to 120 ...