Isolation and Identification of Endophytic Bacteria from Seagrass Thalassia hemprichii as Antibacterial Producer

Bacterial endophytes are the most likely to carry out many biochemical interactions with their host organisms. These interactions allow symbiotic bacteria to produce bioactive substances which are antibacterial. The article describes the potential of endosymbiont bacteria of Thalassia hemprichii at Bunaken marine park in North Sulawesi, Indonesia as antibacterial agents. Six endophytic bacterial isolates were obtained from the seagrass T. hemprichii. The isolates contained phenotypically different colonies which appeared on the agar plate surfaces, namely Th1, Th2, Th3, Th4, Th5 and Th6. From these, Th5 and Th6 could produce antibacterial compounds. Th5 especially was considered very strong in inhibiting the growth of pathogenic bacteria. The antibacterial activity of this bacterium was revealed in both Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli and Salmonella thypi) pathogenetic bacteria. Th5 was identified as Bacillus sp. based on 16S rRNA gene sequences, hence this isolate was called as Bacillus strain Th5 and it could be a promising candidate as antibacterial agent.