Purification and characterization of antifungal compounds from Lactobacillus plantarum HD1 isolated from kimchi.

Strain HD1 with antifungal activity was isolated from kimchi and identified as Lactobacillus plantarum. Antifungal compounds from Lb. plantarum HD1 were active against food- and feed-borne filamentous fungi and yeasts in a spot-on-the-lawn assay. Antifungal activity of Lb. plantarum HD1 was stronger against filamentous fungi than yeast. Antifungal compounds were purified using solid phase extraction (SPE) and recycling preparative-HPLC. Structures of the antifungal compounds were elucidated by electrospray ionization-mass spectrometry and nuclear magnetic resonance. Active compounds from Lb. plantarum HD1 were identified as 5-oxododecanoic acid (MW 214), 3-hydroxy decanoic acid (MW 188), and 3-hydroxy-5-dodecenoic acid (MW 214). To investigate the potential application of these antifungal compounds for reduction of fungal spoilage in foods, Korean draft rice wine was used as a food model. White film-forming yeasts were observed in control draft rice wine after 11 days of incubation. However, film-forming yeasts were not observed in draft rice wine treated with SPE-prepared culture supernatant of Lb. plantarum HD1 (equivalent to 2.5% addition of culture supernatant) until 27 days of incubation. The addition of antifungal compounds to Korean draft rice wine extended shelf-life up to 27 days at 10 °C without any sterilization process. Therefore, the antifungal activity of Lb. plantarum HD1 may lead to the development of powerful biopreservative systems capable of preventing food- and feed-borne fungal spoilage.