Antibacterial Activity Potential of Lactic Acid Bacteria (LAB) Isolates from Palm Sap (Arenga pinnata) from the Wawo Plantation, Tomohon City, North Sulawesi

Abstract

"Lactic acid bacteria (LAB) are one of the dominant groups of bacteria in the palm sap (Arenga pinnata) microbiome. Previous research in the sago palm sap production centers of Tomohon City (Kayawu, Pinaras, and Lahendong) has successfully identified various LAB species, including Lactobacillus casei, Lactobacillus plantarum, Lactobacillus brevis, Lactobacillus buchneri, Leuconostoc mesenteroides, and Leuconostoc sp. This study aims to identify LAB species in sago palm sap from a new location, namely the Wawo Plantation in Tomohon, and to evaluate their potential as natural antibacterial agents. Through 16S rDNA gene sequencing analysis, the isolates obtained were identified as belonging to the newly described genera Lacticaseibacillus and Lactiplantibacillus. Four promising isolates Lactiplantibacillus fabifermentans A1.4, Lacticaseibacillus casei B1.5, Lacticaseibacillus paracasei B1.6, and Lacticaseibacillus paracasei B3.5 were tested for their inhibitory activity against the enteric pathogens Salmonella sp. and Escherichia coli using the well diffusion method. The results showed that all isolates exhibited a strong spectrum of pathogen inhibition. The highest inhibitory activity against Salmonella sp. was demonstrated by the L. paracasei B1.6 isolate, with an inhibition zone of 21.25 mm, while optimal inhibition against E. coli was achieved by L. casei B1.5 at 11.0 mm. These findings confirm that the local BAL strain from Tomohon palm sap has great potential for large-scale development as a biopreservative in the food industry and as a functional probiotic agent"