Isolation and characterization of actinomycetes from farming soil of Kota Belud / Nurfaezah Ibadat

Chaudary et ah, (2013) claimed that microbial pathogen has increasingly resistant to the available antibiotics and as a consequences of this, the demand to discover new antibiotics has been the top priority for scientists (Alanis, 2005 ;Sharma et ah, 2011). Thus, the objectives of this study were to isolate actinomycetes from the farming soil and characterize them as well as screening their antibacterial properties against at least one pathogenic microorganism such as Escherichia coli. A total of 11 actinomycetes were isolated from farming soils of Kampung Rampayan Ulu, Kota Belud. 8 strains of the isolated namely NF1, NF2, NF3, NF4, NF5, NF7, NF9 and NF11 showed an antibacterial activity against at least one test bacteria. The antibacterial activities were performed by primary and secondary screening. Cross streak method was performed for primary screening and both agar well diffusion and disk diffusion for secondary screening. In this study, there are only 2 strains that exceed 20 mm which are NF3 in both primary and secondary screening. The four tested organisms were Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus. Agar well diffusion showed that NF4 has the highest zone of inhibition among rest strains NF1 , NF2, NF3, NF5 and NF11 in inhibiting the Bacillus subtilis, while NF1 inhibited Escherichia coli, NF9 and NF3 inhibited both Pseudomonas aeruginosa and Staphylococcus aureus respectively. There were a few interesting strains such as NF9 that inhibited by the same test organism which Pseudomonas aeruginosa in both agar well and disk diffusion, while NF3 well inhibited by Staphylococcus aureus in agar well diffusion and cross streak method. There was not any specific report on farming soil actinomycetes producing antibiotics in the study areas. Therefore, isolation and characterization of actinomycetes from such areas may contribute to the discovery of new antibiotics and further study should be conducted on the strains that had been retrieved from this farming soil.