Detection of antibiotic-producing Actinobacteria in the sediment and water of Ma'in thermal springs (Jordan)

Detection of new is significant to discover new antibiotics because development of new antibiotics is connected to the characterization of novel bacterial taxa. This study has focused on the identification and isolation of antibiotic-producing from the sediment and the water of Ma'in thermal springs (48-59°C) situated in the center area of Jordan. Samples of sediment and water were transferred to glucose yeast malt agar medium and were cultivated, isolated and identified according to scanning electron microscopy and 16S rRNA gene analysis. Antibacterial activities of the isolates were then tested against different test bacteria by agar well diffusion method. Three different species of were isolated (M1-1, M2-2, M3-2) from sediment samples. Based on 16S rRNA gene analysis, isolate M1-1 was found to have only 90% identity percentage with sp., however, isolates M2-2 and M3-2 were found to be closely related sp. (97%) and (99%), respectively. The antibacterial activity showed that strain M1-1 is active against ATCC 2785 (inhibition zone, 9 mm). Strain M2-2 was found to be active against ATCC 29213 (12 mm), ATCC 11778 (11 mm), and ATCC 25922 (9 mm). In respect to strain M3-2, it was found to be active against ATCC 29213 (14 mm) and ATCC 11778 (9 mm). There were no actinobacterial isolates obtained from water samples despite their significant diversity revealed by our previous metagenomic analysis, which showed the presence of 13 different species dominated by (an Actinobacterium belonging to family ). There were 17 different that could be detected in Ma'in thermal springs (13 unculturable species and 3 culturable species). The culturable were found to have some antimicrobial activity. Further chemical analysis of the bioactive compounds is recommended.