Objective: To isolate and screen for the anti-microbial properties of actinomycetes from marine soil sediments and sponges.
Methods: The samples of sponges and sediments were collected from various locations on the coast of Andhra Pradesh. Isolation of actinomycetes was done by plating them on the starch casein agar, Kuster’s agar, actinomycete isolation agar, and potassium tellurite agar medium using the dilution technique. Various pathogenic bacterial strains, fungal strains, and yeasts were obtained from the Microbial Type Culture Collection, Chandigarh, India, and the National Collection of Industrial Microorganisms, Pune, India.
Results: A total of six different soil sediments were collected from the coast of Andhra Pradesh at depths ranging from 1 to 20 m. From the 9 different samples collected, 22 colonies of actinomycetes were isolated. Well-separated and pure colonies of 12 actinomycetes were selected. Of these, nine actinomycetes were active against Gram-positive bacteria, three against Gramnegative bacteria, four against filamentous fungi, and one against yeast. The crude extracts prepared from three potential isolates exhibited both anti-bacterial and anti-fungal activities. Based on morphological, physiological, and biochemical characteristics, the most effective isolate was identified (AP 13) as belonging to the genus Streptomyces.
Conclusion: With careful evaluation, using previously published species of the genus Streptomyces, the isolate was identified as the strain Streptomyces fradiae.