Actinomycetes of secondary metabolite producers from mangrove sediments, Central Java, Indonesia.

Background And Aim: Actinomycetes are a group of Gram-positive bacteria with a fungus-like morphology. Their natural habitat encompasses terrestrial and water areas, including mangrove ecosystems. This study aimed to assess the and genes as the producers of secondary metabolites and to determine the target bacterial species using molecular DNA tests.

Materials And Methods: In this study, we isolated bacteria from sediment samples from mangrove forests located on Karimunjawa Islands and in Semarang city, purified bacteria, screened for antibacterial activity, extracted bacterial DNA, amplified the gene, detected and amplified the and genes, amplified and sequenced the 16S rRNA, processed molecular data, and simulated a map of secondary metabolite producing genes.

Results: Samples from the Karimunjawa Islands yielded 19 bacterial isolates, whereas samples from Semarang yielded 11 bacterial isolates after culture in different media. Further experiments identified three active isolates, which were termed PN.SB.6.2, S.SK.6.3, and S.SK.7.1, against pathogenic species of , , and . Isolate PN.SB.6.2 was determined to possess three biosynthetic gene clusters (BGCs), whereas the remaining two isolates, S.SK.6.3 and S.SK.7.1, only possessed two BGCs, namely, and .

Conclusion: Products were estimated to be in the , thiopeptide, RiPP-like, siderophore, betalactone, terpene, Type III , CDPS, and lassopeptide groups. DNA identification of the isolates found three species of actinomycetes with antibacterial potential, namely, , , and .