Tehran University of Medical Sciences Iranian Journal of Microbiology 2008-3289 12 5 2020 10 31 437 444 EN Anik Ma'unatin Department of Agricultural Technology, Brawijaya University, Malang, East Java, Indonesia AND Department of Chemistry, Maulana Malik Ibrahim State Islamic University Malang, Malang, East Java, Indonesia Harijono Harijono Department of Agricultural Technology, Brawijaya University, Malang, East Java, Indonesia Elok Zubaidah Department of Agricultural Technology, Brawijaya University, Malang, East Java, Indonesia Muhaimin Rifa'i Department of Biology, Brawijaya University, Malang, East Java, Indonesia 2020 03 10 2020 08 24 Background and Objectives: Lontar (Borassus flabellifer L.) is widely grown in Indonesia and one of its products is palm sap. Palm sap contains a high level of sugar, making it suitable as a medium to increase the lactic acid bacteria (LAB) production of exopolysaccharides (EPS). This study aimed to isolate the EPS-producing LAB from palm sap and evaluate its EPS production. LAB isolation was carried out on MRS agar containing 0.5% CaCO3. Materials and Methods: The screening and production of EPS were carried out on MRS media supplemented with 10% sucrose. The molecular identification of the selected EPS-producing LAB was based on 16S rDNA. A quantitative analysis of EPS polymer dry mass and total sugar was conducted using one-way ANOVA. Results: In this study, five EPS-producing LABs were found: Fructobacillus fructosus N4, Leuconostoc mesenteroides N5, Leuconostoc mesenteroides N7, Leuconostoc mesenteroides N9, and Fructobacillus fructosus N10. The highest EPS yield in liquid media was 10.997 ± 1.591 g/L by Leuconostoc mesenteroides N7, whereas the lowest was 4.505 ± 0.459 g/L by Fructobacillus fructosus N10. Conclusion: This study found Fructobacillus fructosus strains as EPS producers that have never been reported before. https://ijm.tums.ac.ir/index.php/ijm/article/view/2517 https://ijm.tums.ac.ir/index.php/ijm/article/download/2517/1279