Analysis of Cultivable Microbial Community during Kimchi Fermentation Using MALDI-TOF MS

Abstract

Kimchi, a traditional Korean fermented vegetable, has received considerable attention for its health-promoting effects. This study analyzes the cultivable microbial community in kimchi fermented at different temperatures using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) to comprehensively understand the factors affecting the quality of kimchi. Of the 5204 strains isolated from kimchi, aligned with the in-house database, 4467 (85.8%) were correctly identified at the species level. The fermentation temperature affected the microbial community by varying the pH and acidity, which was mainly caused by temperature-dependent competition between the different lactic acid bacteria (LAB) species in kimchi. LAB, such as Levilactobacillus (Lb.) brevis and Lactiplantibacillus (Lpb.) plantarum associated with rancidity and tissue softening, proliferated faster at higher temperatures than at low temperature. In addition, LAB, such as Latilactobacillus (Lat.) sakei and Leuconostoc (Leu.) mesenteroides, which produce beneficial substances and flavor, were mainly distributed in kimchi fermented at 4 °C. This study shows as a novelty that MALDI-TOF MS is a robust and economically affordable method for investigating viable microbial communities in kimchi.

Effect of Enterotoxigenic Escherichia coli on Microbial Communities during Kimchi Fermentation

“…Lactobacillus -related genera, Leuconostoc , and Weissella , which play an important role in kimchi fermentation, are bacteria that produce organic acids, bacteriocin, and flavor ingredients during kimchi fermentation [ 11 , 27 , 33 ]. Also, these genera produce organic acids (lactic acid and acetic acid) from carbohydrates during kimchi fermentation, lowering the pH value according to the fermentation stage and causing changes in the microbial communities [ 27 , 34 ]. In this study, ETEC was decreased with an increase in Lactobacillus -related genera, which may be associated with bacteriocin or organic acid production.…”

The Weissella and Periweissella genera: up-to-date taxonomy, ecology, safety, biotechnological, and probiotic potential

“…As for the identification of weissellas, biochemical methods such as those based on the comparison of total soluble cell protein patterns (Dicks, 1995 ; Tsakalidou et al, 1997 ) and profiles of cellular fatty acids (Samelis et al, 1998 ), as well as commercial identification kits such as the Phoenix Automated Microbiology System (Becton Dickinson Diagnostic Systems, Sparks, MD), theVitek2 system (Bio Merieux, Marcy l'Etoile, France), the API50 CHL kit (BioMérieux, Lyon, France) (Lee K. W. et al, 2012 ), and the RapID™ STR System (Thermo Scientific, Hudson, NH, USA), do not allow an accurate and reliable identification (Fusco et al, 2015 ; Sturino, 2018 ). The culture-based identification of weissellas has been improved by matrix-assisted laser desorption–ionization time of flight mass spectrometry (MALDI-TOF MS) (Albesharat et al, 2011 ; Fairfax et al, 2014 ; Lee M. R. et al, 2015 ; Kim et al, 2017 , 2021a , b ; Nacef et al, 2017 ; Wang et al, 2020b ; Joglekar et al, 2023 ).…”

Differentiating between Enterococcusfaecium and Enterococcuslactis by Matrix-Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry

“…Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is often used to identify and differentiate microorganisms [ 9 , 10 ]. The approach is rapidly replacing analytical phenotypic and conventional biochemical identification methods, especially in clinical microbiology laboratories [ 11 , 12 ].…”