The Microbial Diversity of Non-Korean Kimchi as Revealed by Viable Counting and Metataxonomic Sequencing

Abstract

Kimchi is recognized worldwide as the flagship food of Korea. To date, most of the currently available microbiological studies on kimchi deal with Korean manufactures. Moreover, there is a lack of knowledge on the occurrence of eumycetes in kimchi. Given these premises, the present study was aimed at investigating the bacterial and fungal dynamics occurring during the natural fermentation of an artisan non-Korean kimchi manufacture. Lactic acid bacteria were dominant, while Enterobacteriaceae, Pseudomonadaceae, and yeasts progressively decreased during fermentation. Erwinia spp., Pseudomonasveronii, Pseudomonasviridiflava, Rahnellaaquatilis, and Sphingomonas spp. were detected during the first 15 days of fermentation, whereas the last fermentation phase was dominated by Leuconostoc kimchi, together with Weissellasoli. For the mycobiota at the beginning of the fermentation process, Rhizoplaca and Pichia orientalis were the dominant Operational Taxonomic Units (OTUs) in batch 1, whereas in batch 2 Protomyces inundatus prevailed. In the last stage of fermentation, Saccharomyces cerevisiae, Candida sake,Penicillium, and Malassezia were the most abundant taxa in both analyzed batches. The knowledge gained in the present study represents a step forward in the description of the microbial dynamics of kimchi produced outside the region of origin using local ingredients. It will also serve as a starting point for further isolation of kimchi-adapted microorganisms to be assayed as potential starters for the manufacturing of novel vegetable preserves with high quality and functional traits.

Variations in nutritional and microbial composition of napa cabbage kimchi during refrigerated storage

“…However, previous studies have reported significant changes to the microbial profile of kimchi during the fermentation process (Maoloni et al, 2020). Even though not statistically significant, the mean relative abundance of Firmicutes increased over 3 months of storage before starting to decline.…”

Ultramicrobacteria in various fermented cabbages

“…Further, if the UMB community was not separated via TFF, Cellulomonas biazotea and TM7a would not have been confirmed in kimchi. Available literature on kimchi microbial community analysis was reviewed, which led to the conclusion that Cellulomonas biazotea and TM7a have not yet been reported in kimchi via neither culture-dependent nor culture-independent methods (Cho et al, 2006; Jung et al, 2014; H.-W. Lee et al, 2017; Maoloni et al, 2020; E. J.…”

New Insight into Bacterial Interaction with the Matrix of Plant-Based Fermented Foods

“…This pH value was related to the presence of lactic and nitric acids [ 50 ]. Other authors have shown a decrease in pH from a value of 5.0–5.4 at the beginning of fermentation of kimchi to 4.0 after 57 days of fermentation [ 51 ]. In turn, the pH value during fermentation of pineapple increased from 3.4 to 4.0 for fruits fermented by W. cibaria and to 3.5 for those fermented by Ln.…”

“…Changes in the microbial community during fermentation of plant products may additionally be caused by the production of antibiotics by microorganisms, including bacteriocins, which inhibit the growth of harmful bacteria [ 50 ]. Microbial analysis of kimchi carried out by Maoloni et al revealed formation of an active microbial community consisting predominantly of mesophilic aerobes and lactic acid bacteria [ 51 ]. The study showed that the total number of these bacteria in the product after nine days of fermentation reached >8 log10 CFU/g.…”

“…At this stage, Leuconostoc kimchi and Weissella soli were the most abundant bacteria present in the product. These changes were related to the accumulation of organic acids produced by LAB, which create unfavorable environmental conditions for the existence of undesirable bacteria [ 51 ]. Research conducted on a bean-based beverage extracted from germinated seeds of white bean cv.…”