title: Microbial succession and metabolite changes during long-term storage of Kimchi.
abstract: Kimchi is often stored for a long period of time for a diet during the winter season because it is an essential side dish for Korean meals. In this study pH, abundance of bacteria and yeasts, bacterial communities, and metabolites were monitored periodically to investigate the fermentation process of kimchi for 120 d. Bacterial abundance increased quickly with a pH decrease after an initial pH increase during the early fermentation period. After 20 d, pH values became relatively stable and free sugars were maintained at relatively constant levels, indicating that kimchi fermentation by lactic acid bacteria (LAB) was almost completed. After that time, a decrease in bacterial abundance and a growth in Saccharomyces occurred concurrently with increased free sugar consumption and production of glycerol and ethanol. Finally, after 100 d, the growth of Candida was observed. Community analysis using pyrosequencing revealed that diverse LAB including Leuconostoc citreum, Leuconostoc holzapfelii, Lactococcus lactis, and Weissella soli were present during the early fermentation period, but the LAB community was quickly replaced with Lactobacillus sakei, Leuconostoc gasicomitatum, and Weissella koreensis as the fermentation progressed. Metabolite analysis using (1) H-NMR showed that organic acids (lactate, acetate, and succinate) as well as bioactive substances (mannitol and gamma-aminobutyric acid (GABA)) were produced during the kimchi fermentation, and Leuconostoc strains and Lactobacillus sakei were identified as the producers of mannitol and GABA, respectively.
authors.affiliation: Dept. of Life Science, Chung-Ang Univ., Seoul, 156-756, Republic of Korea.
authors.forename: Sang Hyeon
authors.initials: SH
authors.lastname: Jeong
authors.forename: Se Hee
authors.initials: SH
authors.lastname: Lee
authors.forename: Ji Young
authors.initials: JY
authors.lastname: Jung
authors.forename: Eun Jin
authors.initials: EJ
authors.lastname: Choi
authors.forename: Che Ok
authors.initials: CO
authors.lastname: Jeon
mesh_terms: D000085:Acetates / Q000378:metabolism; D002175:Candida / Q000302:isolation & purification / Q000378:metabolism; D005285:Fermentation; D005511:Food Handling; D005516:Food Microbiology; D061353:Food Storage / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D019344:Lactic Acid / Q000378:metabolism; D007778:Lactobacillus / Q000302:isolation & purification / Q000378:metabolism; D007934:Leuconostoc / Q000302:isolation & purification / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D008353:Mannitol / Q000378:metabolism; D012150:Polymorphism, Restriction Fragment Length; D025341:Principal Component Analysis; D012336:RNA, Ribosomal, 16S / Q000302:isolation & purification; D012440:Saccharomyces / Q000302:isolation & purification / Q000378:metabolism; D017422:Sequence Analysis, DNA; D019802:Succinic Acid / Q000378:metabolism; D058836:Weissella / Q000302:isolation & purification / Q000378:metabolism; D005680:gamma-Aminobutyric Acid / Q000378:metabolism
chemical_list: D000085:Acetates; D012336:RNA, Ribosomal, 16S; D019344:Lactic Acid; D008353:Mannitol; D005680:gamma-Aminobutyric Acid; D019802:Succinic Acid