Screening, Identification, and Characterization of Two Folate-Producing Lactiplantibacillus plantarum Strains

In this study, two folate-producing Lactiplantibacillus plantarum bacteria, known as Grx1201 and Grx1202, were screened with folic acid assay medium (FAAM). When 4 μg/100 mL of exogenous folic acid was added to FAAM, the maximum folate production of Grx1201 and Grx1202 reached 9.01 μg/100 mL and 10.47 μg/100 mL, respectively, which were 2.30 and 2.14 times greater than those of the control. High survival rates of Grx1201 and Grx1202 were observed at pH 3.0. Antibiotic resistance, biogenic amine-synthesizing ability, and hemolytic ability analyses revealed that Grx1201 and Grx1202 were safe for biological application. To determine the reason for the synthesis of folate, the transcription levels of key genes in the folate synthesis pathway in Grx1201 and Grx1202 were analyzed and compared. Grx1201 and Grx1202 reported here can greatly improve the folate content in functional foods.