Isolation, Screening and Characterization of Antibiotic-Producing Actinomycetes from Rhizosphere Region of Different Plants from a Farm of Sungai Ramal Luar, Malaysia

Abstract

A total of 25 soil samples were collected from rhizospehere regions of different plants from a farm in sungai ramal luar, malaysia. These samples were divided into two sets for the isolation of actinomycetes: one receiving the treatment with calcium carbonate and other set without calcium carbonate. A total of 300 actinomycetes isolates with different morphology were obtained. Of 50 fast-growing isolates, four potential antibiotic producing isolates were obtained by employing primary and secondary screening. The antibacterial activity of crude compounds extracted from the actinomycetes was tested against bacillus subtilis, staphylococcus aureus, salmonella sp. And serratia sp. Two actinomycete cultures, lm1a and mg1a that antagonized most bacteria with largest inhibition zones (b. Subtilis: 20.5 mm, salmonella sp.: 13.0 mm, serratia sp.: 13.0 mm, s. Aureus: 19.0 mm) during screening were selected for further study. Both of the isolates were found to be growing at ph and temperature ranges of 5.0-9.0 and 30-37°c respectively and tolerated nacl concentrations as high as 7%. Further, the isolates were presumed as streptomyces sp.