Journal of Microbiology

Research Support, Non-U.S. Gov'ts

Cyclic Dipeptides from Lactic Acid Bacteria Inhibit the Proliferation of Pathogenic Fungi: Min-Kyu Kwak , Rui Liu , Min-Kyu Kim , Dohyun Moon , Andrew HyoungJin Kim , Sung-Hyun Song , Sa-Ouk Kang; J. Microbiol. 2014;52(1):64-70. Published online January 4, 2014; DOI: https://doi.org/10.1007/s12275-014-3520-7

Abstract: Lactobacillus plantarum LBP-K10 was identified to be the most potent antifungal strain from Korean traditional fermented vegetables. The culture filtrate of this strain showed remarkable antifungal activity against Ganoderma boninense. Five fractions from the culture filtrate were observed to have an inhibitory effect against G. boninense. Also, the electron ionization and chemical ionization indicated that these compounds might be cyclic dipeptides. Of the five active fractions, two fractions showed the most significant anti-Ganoderma activity, and one of these fractions inhibited the growth of Candida albicans. These compounds were identified to be cis-cyclo(L-Val-L-Pro) and cis-cyclo(L-Phe-L-Pro), as confirmed by X-ray crystallography.

Cyclic Dipeptides from Lactic Acid Bacteria Inhibit Proliferation of the Influenza A Virus: Min-Kyu Kwak , Rui Liu , Jun-Oh Kwon , Min-Kyu Kim , Andrew HyoungJin Kim , Sa-Ouk Kang; J. Microbiol. 2013;51(6):836-843. Published online December 19, 2013; DOI: https://doi.org/10.1007/s12275-013-3521-y

Abstract: We isolated Lactobacillus plantarum LBP-K10 from the traditional Korean fermented food kimchi. When organic acids were removed, the culture filtrate of this isolate showed high antiviral activity (measured using a plaque-forming assay) against the influenza A (H3N2) virus. Two fractions that were active against influenza A virus were purified from the culture filtrate using a C18 column with high-performance liquid chromatography. These active fractions were crystallized and identified to be the cyclic dipeptides cis-cyclo (L-Leu-L-Pro) and cis-cyclo(L-Phe-L-Pro) using gas chromatography-mass spectrometry; this identification was confirmed by X-ray crystallography. These cyclic dipeptides were identified in the culture filtrate of other lactic acid bacteria, including Lactobacillus spp., Leuconostoc spp., Weissella spp., and Lactococcus lactis.

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