Molecular Identification of Lactic Acid Bacteria as Probiotic Candidates Encoding the Fructosyltransferase Gene (FTF) from Pakoba Fruit (Syzygium sp.)

The formation of extracellular polysaccharide polymers (EPS) is catalyzed by the enzyme Fructosyltransferase (ftf), derived from lactic acid bacteria (LAB). These enzymes produce various homopolymers, including fructans, levans, inulin, and fructooligosaccharides (FOS), which are beneficial as prebiotics, emulsifiers, stabilizers, and gelling or water-binding agents in food products. In the health sector, they also exhibit potential antitumor, antiulcer, and immunomodulatory properties and help lower cholesterol levels. This study aims to identify lactic acid bacteria as probiotic candidates encoding the fructosyltransferase gene (ftf) from Pakoba fruit (Syzygium sp.). The methods used in this study included reculturing six isolates of probiotic candidate LAB-EPS, DNA isolation, amplification of the 16S rRNA gene using universal primers (27F and 1492R), and amplification of the ftf gene using specific primers (5FTF and 6FTF). The amplification of the 16S rRNA gene produced amplicons of approximately 1400 bp, while the amplification of the ftf gene yielded amplicons of approximately 800 bp. Two of the six probiotic LAB-EPS isolates were found to harbor the ftf gene: the PM6.4 and PM5.3 isolates. Identification based on the 16S rRNA gene sequence revealed that the PM6.4 and PM5.3 isolates belong to the species Lactiplantibacillus plantarum. This study concludes that the two LAB-EPS probiotic isolates from Pakoba fruit (Syzygium sp.) contain the FTF gene, identified as Lactiplantibacillus plantarum.