SUMMARYResearch backgroundLactic acid bacteria (LAB) are known to produce folate. However, this ability is highly strain-dependent. Folate synthesis in specific LAB strains is affected by the availability of folate, which can be consumed by other LAB under certain conditions. Moreover, differences in folate synthesis capabilities are related to the presence of folate biosynthesis-related genes and regulation of this pathway.Experimental approachAs basic information to better understand the regulation of folate biosynthesis among different LAB species and strains, folate biosynthetic genes were screened and identified in folate-producing and non-folate-producing LAB isolated from various local food sources in Indonesia. The extracellular folate productivity amounts of the isolates were analyzed using high-performance liquid chromatography with a diode array detector (HPLC-DAD).Results and conclusionsEleven of the thirteen tested LAB isolates had all of the eight genes involved in folate biosynthesis (folE,folQ,folB,folK,folP,folC1,folAandfolC2). Furthermore, these isolates produced extracellular folate ranging from 10.37 to 31.10 µg/mL. In contrast, two non-folate-producing isolates lacked several folate biosynthetic genes, such asfolQ,folPandfolA, which is possibly the reason for their inability to synthesize folatede novo. Phylogenetic tree construction revealed that the folate biosynthetic genes (excludingfolKandfolP) from six distinct species of folate-producing LAB isolates were monophyletic with homologous genes from other LAB species in the database.Novelty and scientific contributionIn this study, the distribution of folate biosynthetic genes in various LAB species was determined. The findings from this research support the use of folate biosynthesis marker genes in the genotypic screening for folate-producing LAB.