Antifungal activity of actinomycete isolated from water samples

Variety of bioactive molecules such as antimicrobial can be produced by actinomycetes. In addition, actinomycete is important as a constituent of the normal flora of sand filters because they are capable to degrade organic compounds. Samples were collected in a 1.5 mL centrifuge tube from diverse locations namely Universiti Malaysia Kelantan Jeli Campus, Kedah, Terengganu and lndah Water Konsortium, Negeri Sembilan. For each water sample, at least three dilutions were made. Serially diluted samples were inoculated on Actinomycetes media (AM) plates and incubated at 28 °C for 1 to 2 weeks before the morphological selection. The antifungal activities of actinomycetes were tested against three different test organisms; Aspergillus niger, Rhizopus stolonifer and Fusarium solani using agar plug method. If the antibiotic produced by the organism inhibits the growth of the test organism, an inhibition zone is formed around the agar plugs. A total of 14 water samples were collected over a 3 month period and a total of 15 colonies were isolated. The result turns out those only 6 out of 15 colonies were distinct actinomycetes. The characterization of actinomycete morphology is done by using naked eyes. The morphological characteristics such as the color of aerial mycelium, presence of soluble pigment were observed and recorded. The plates were incubated for 2 to 3 weeks at 28 °C. Fifteen isolates were obtained throughout this study. Somehow only 6 isolates identified to be different. Based on the percentage of inhibitory, 50% isolates were found active against all fungi tested. Findings of the present study conclude that varies places is the potential ecosystem for antifungal actinomycetes which deserves for further research. One of the isolated actinomycete identified as a good candidate for the isolation of antifungal properties since it showed good activity in the preliminary and secondary screening experiments.