Antibacterial Ability of Seaweed Endophytic Bacteria (Turbinaria ornata, Sargassum crassifolium, and Sargassum polycystum) Against Skin Disease Agents

Abstract

Bioactive substances that can prevent the growth of pathogenic germs can be produced by endophytic bacteria This study aims to identify seaweed endophytic bacteria (Turbinaria ornata, Sargassum crassifolium, Sargassum polycystum) and their potential antibacterial activity against skin disease agents (Staphylococcus aureus and Staphylococcus epidermidis). In February 2023 (the rainy season), seaweed was harvested from the waters off Panjang Island in Jepara Regency, Central Java, Indonesia. Endophytic bacterial isolates that had been effectively isolated and purified were directly tested for antibacterial activity. Three isolates with the best antibacterial activity were extracted using the ethyl acetate solvent. The extract samples will be put through additional antibacterial testing using the minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and paper disc diffusion procedures. Using the thin layer chromatography (TLC), the class of chemical components in the extract was determined. A molecular technique based on the 16s rRNA gene (1,400 bp) was used to identify endophytic bacterial isolates. Three species of seaweed yielded 25 isolates of endophytic bacteria: 11 from T. ornata, 7 from S. crassifolium, and 7 from S. polycystum. To.09.pp, To.10.pp, and Sc.06.pp were the 3 isolates with the highest antibacterial activity in the direct challenge test. Zone of inhibition results from subsequent antibacterial testing using paper disc diffusion ranged from medium to very strong intensity. To.10.pp sample’s MIC test yielded the best results, with S. aureus and S. epidermidis concentrations of 937.5 and 1,875 µg/mL, respectively. MBC test yielded the highest findings, with S. aureus and S. epidermidis concentrations of 1,875 and 1,875 µg/mL, respectively. The To.10.pp sample yielded terpenoids, alkaloids, and flavonoids, according to TLC analysis of chemical constituent groups. Acinetobacter indicus strain 80-1-2 and Vibrio harveyi strain B14-1 were identified as potential endophytic bacteria from T. ornata, and Acinetobacter indicus strain 80-1-2 from S. crassifolium. HIGHLIGHTS Endophytic seaweed Turbinaria ornata, Sargassum crassifolium, and Sargassum polycystum showed antibacterial activity against Staphylococcus aureus ATCC 29213 and Staphylococcus epidermidis FNCC 0048 Acinetobacter indicus strain 80-1-2, and Vibrio harveyi strain B14-1 were all successfully identified by molecular analysis as potential endophytic bacteria Identification of compounds using Thin Layer Chromatography (TLC) showed the presence of terpenoids, alkaloids, and flavonoids GRAPHICAL ABSTRACT