Microbial Succession in Kimchi Fermented With U.S.-Grown Ingredients

IntroductionKimchi fermentation is governed by dynamic microbial succession that strongly influences product quality, consistency, and safety. As kimchi production expands beyond Korea, concerns have emerged regarding whether kimchi produced with non-Korean ingredients follows fermentation patterns comparable to traditional Korean kimchi. In particular, the relative contributions of soil-associated microbiota, raw ingredient–associated microbiota, and fermentation-driven selection to lactic acid bacteria (LAB) succession remain poorly understood in overseas kimchi production systems.MethodsKimchi was prepared using napa cabbage harvested in spring, fall, and winter, with all ingredients sourced exclusively from Texas, representing an overseas production system. Samples were collected from soil, raw ingredients, and fermenting kimchi on a weekly basis for up to four weeks. Viable microbial populations were enumerated using plate count agar (PCA) for total aerobic bacteria and de Man, Rogosa and Sharpe agar (MRS) for LAB. Physicochemical changes were monitored by measuring pH and titratable acidity. Microbial community dynamics were characterized using 16S ribosomal RNA (16S rRNA) gene amplicon sequencing. Fermentation patterns of Korean-origin kimchi were evaluated through comparative analysis of representative published studies. ResultsMicrobial tracking revealed clear distinctions between soil-associated and raw ingredient–associated communities. Soil samples exhibited high microbial diversity dominated by environmental taxa, whereas raw ingredients showed selective enrichment of LAB relevant to fermentation. Weekly monitoring confirmed consistent microbial succession, characterized by early dominance of Leuconostoc spp., followed by increased prevalence of acid-tolerant LAB, including Latilactobacillus and Lacticaseibacillus spp. Soil-associated microbes were not directly conserved in the kimchi microbiome, indicating selective enrichment during fermentation rather than direct soil transmission. Despite all ingredients originating from Texas, LAB succession patterns were largely comparable to reported microbial dynamics of Korean-origin kimchi, with differences mainly observed during early fermentation stages.SignificanceThis study demonstrates that kimchi produced entirely with overseas ingredients can exhibit LAB succession comparable to that of Korean-origin kimchi. By distinguishing soil– and raw ingredient–associated microbiota and tracking weekly microbial succession, this work clarifies the role of ingredient origin in early fermentation and supports the development of standardized fermentation strategies for global kimchi production.