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Bacterial diversity in the initial fermentation stage of Korean and Chinese kimchi

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Abstract

The purpose of this research is to draw the bacterial community difference between Korean and Chinese kimchi for future use in the confirmation of kimchi origin. Initial fermentation stage kimchi samples (above pH 5) were used for the analysis of bacterial diversity. From 26 Korean kimchi samples, 1,017 strains in the 45 genera and from 22 Chinese kimchi samples, 842 strains in the 54 genera were isolated with use of marine medium, nutrient medium, succinate minimal medium (SMM), leuconostocs selective medium (LUSM) agars. In the order of isolated numbers, Bacillus, Weissella, Leuconostoc, Pseudomonas, and Lactobacillus genera and Bacillus, Weissella, Lactobacillus, Pseudomonas, Serratia, and Enterobacter genera were predominated in Korean and Chines kimchi, respectively. Among the isolated lactic acid bacteria, Weissella spp. were isolated most dominantly owing to the biased growth of Weissella spp. on LUSM agar. Species in the genera Leuconostoc and Lactobacillus were the next frequently isolated LAB from Korean and Chinese kimchi, respectively. Weissella confusa was isolated only from Korean kimchi and W. soli and Serratia proteamculans were isolated only from Chinese kimchi. They have a possibility to be used as target bacteria to differentiate Korean kimchi from Chinese kimchi.

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... The primers and two enzymes used in this study could detect and discriminate the dominant LAB found in kimchi: Leuconostoc spp., Lactobacillus spp., Weissella spp., Enterococcus spp., Pediococcus spp., and Bacillus spp. The assay was not able to identify minorities existing in the early stage of kimchi such as species in the genera, Pseudomonas and Serratia [9]. The taxonomic res- olution level of T-RFLP analysis was between species and genus. ...
... In our previous bacterial community analysis in the initial fermentation stage kimchi samples (above pH 5) using 4 kinds of media, Bacillus spp. were the predominant species [9]. Recently, Chang and others [1] reported Bacillus spp. as the most populous Gram-positive bacteria in the initial stage of kimchi, maintaining their cell numbers until kimchi fermentation reached around pH 4. We also found through T-RFLP analysis that Bacillus spp. ...
... However, the succession of major LAB involved in kimchi fermentation was successfully analyzed and corresponded well to previously reported bacteria community studies by culture-independent methods [2,5,7,11]. In our previous research, bacterial diversities in kimchi made in Korea and China were evaluated by culture-dependent methods to evaluate the bacterial community differences between kimchi manufactured at different geographic origins and to find the existence of target bacteria for future use in the confirmation of kimchi origin [9]. In order to maximize the bacterial diversity in kimchi, kimchi samples of initial fermentation stage (above pH 5) were used. ...
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Terminal Restriction Fragment Length Polymorphism (T-RFLP) analysis was adopted to explore rapid differentiation in the diversity and dynamics of bacteria in kimchi made in Korea and China for future application in kimchi origin discrimination. T-RFLP analysis supported the reproducible and rapid detection of major lactic acid bacteria known to be involved in kimchi fermentation. The taxonomic resolution level of this T-RFLP analysis was between the species and genus level, but was not specific enough for the detection of a bacterium found only in one origin, either Korea or China. The bacterial community structure successions in kimchi samples from Korea and China analyzed by T-RFLP analysis occurred with a similar pattern. Bacillus spp. which were not detected in the early microbial studies of kimchi were constantly detected until the late fermentation stage of kimchi in our T-RFLP analysis and their existence was proved by culture-based identification. Additionally, sporulation of Bacillus spp. during kimchi fermentation was discovered.
... 김치 발효에 관여하 는 미생물은 약 200여종 이상으로 알려져 있으며 (8,9) 김치 의 주된 발효미생물이 유산균이며 이와 같이 살아있는 유산 균을 비타민, 무기질이 풍부한 채소와 함께 섭취할 수 있는 식품이라는 사실이 김치의 차별화된 우수성으로 설명되고 있다 (10,11). Codex의 (8,13,(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29), 유해세 균(식중독균)의 조사 (16,(30)(31)(32)(33)(34)및 오염지표 미생물 (35)(36)(37) 등 많은 연구가 있으며, 이 때 사용된 실험적 방법도 미생물 배양방법, 분자생물학적 방법(PCR, 16S rRNA gene 분석법, (13,14,21,24,25,29). 기존의 김치 내 미생물 관련 연구에서 발효숙성 중 미생 물학적 변화에 관련된 연구는 주로 유산균의 변화 중심으로 이루어져 있고 (10,11,14,25,27,34), 김치 내 유해세균은 주 로 식중독균 중심으로 이루어져 있으며 (16,(30)(31)(32)(33)(34)38), 김치 내 미생물학적 연구는 김치 내에서 분리 동정될 수 있는 미생물균종에 대한 연구들 (13,24,26) (Fig. 3,4). 그러나 김치의 산도가 pH 5.0이하로 떨어지는 발효중기로 들어서면 모든 김치시료에서의 유산 균이 가장 높은 빈도로 검출 (Fig. 3,4) ...
... 김치 발효에 관여하 는 미생물은 약 200여종 이상으로 알려져 있으며 (8,9) 김치 의 주된 발효미생물이 유산균이며 이와 같이 살아있는 유산 균을 비타민, 무기질이 풍부한 채소와 함께 섭취할 수 있는 식품이라는 사실이 김치의 차별화된 우수성으로 설명되고 있다 (10,11). Codex의 (8,13,(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29), 유해세 균(식중독균)의 조사 (16,(30)(31)(32)(33)(34)및 오염지표 미생물 (35)(36)(37) 등 많은 연구가 있으며, 이 때 사용된 실험적 방법도 미생물 배양방법, 분자생물학적 방법(PCR, 16S rRNA gene 분석법, (13,14,21,24,25,29). 기존의 김치 내 미생물 관련 연구에서 발효숙성 중 미생 물학적 변화에 관련된 연구는 주로 유산균의 변화 중심으로 이루어져 있고 (10,11,14,25,27,34), 김치 내 유해세균은 주 로 식중독균 중심으로 이루어져 있으며 (16,(30)(31)(32)(33)(34)38), 김치 내 미생물학적 연구는 김치 내에서 분리 동정될 수 있는 미생물균종에 대한 연구들 (13,24,26) (Fig. 3,4). ...
... 김치 발효에 관여하 는 미생물은 약 200여종 이상으로 알려져 있으며 (8,9) 김치 의 주된 발효미생물이 유산균이며 이와 같이 살아있는 유산 균을 비타민, 무기질이 풍부한 채소와 함께 섭취할 수 있는 식품이라는 사실이 김치의 차별화된 우수성으로 설명되고 있다 (10,11). Codex의 (8,13,(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29), 유해세 균(식중독균)의 조사 (16,(30)(31)(32)(33)(34)및 오염지표 미생물 (35)(36)(37) 등 많은 연구가 있으며, 이 때 사용된 실험적 방법도 미생물 배양방법, 분자생물학적 방법(PCR, 16S rRNA gene 분석법, (13,14,21,24,25,29). 기존의 김치 내 미생물 관련 연구에서 발효숙성 중 미생 물학적 변화에 관련된 연구는 주로 유산균의 변화 중심으로 이루어져 있고 (10,11,14,25,27,34), 김치 내 유해세균은 주 로 식중독균 중심으로 이루어져 있으며 (16,(30)(31)(32)(33)(34)38), 김치 내 미생물학적 연구는 김치 내에서 분리 동정될 수 있는 미생물균종에 대한 연구들 (13,24,26) (Fig. 3,4). 그러나 김치의 산도가 pH 5.0이하로 떨어지는 발효중기로 들어서면 모든 김치시료에서의 유산 균이 가장 높은 빈도로 검출 (Fig. 3,4) ...
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To investigate the sanitary-quality level of commercial kimchi in South Korea, the pH, acidity, and microbial-flora changes in the kimchi were determined. Samples of kimchi produced by three different manufacturers (a small grocery store, a small/medium-sized enterprise, and a large food company) were collected. Freshly made kimchi was purchased and fermented at 10^{\circ}C for 10 days. The pH of the commercial kimchi on the purchased day was approximately pH 5.8, and that on the 10^{th} day of fermentation was {\simeq}pH 4.1. The kimchi purchased from a large company showed a more rapid decline in pH level during fermentation. The saltiness of the kimchi purchased from a medium-sized company was slightly higher than those of the other commercial kimchi samples. The saccharinity index of the kimchi produced by a small grocery store was higher than those of the other samples, and its value deviation was also higher than those of the other commercial kimchi samples. A higher total viable-cell count and a higher lactic-acid bacteria (LAB) count were detected in the kimchi from the large food company at the beginning of fermentation compared to the samples of the two other kimchi manufacturers. The highest cell numbers of gram-positive bacteria (except LAB) and coliform bacteria were detected from the small-grocery-store kimchi, but the coliform bacteria count gradually decreased during fermentation although such bacteria were still detected until the 10^{th} day of fermentation. In contrast, coliform bacteria were not detected in the samples from the medium-sized and large food companies. Yeast, which is detected in over-ripened kimchi, was detected in the unfermented kimchi from the small grocery store, which had a below-0.36% acidity level. The gram-positive bacteria (except LAB) that were detected in all the tested commercial kimchi samples were determined to be Bacillus spp., and the gram-negative bacteria were determined to be Escherichia coli, Enterobacter spp., Sphingomonase spp., and Strenophomonas spp. The proportions of all the aforementioned bacteria in the kimchi samples, however, were different depending on the samples that were taken. These results indicate that a more sanitary kimchi production process and a more systematic kimchi production manual should be developed to industrialize and globalize kimchi.
... Comparison of the two methods for bacterial community analysis showed that even though major bacterial communities are highly similar at the genus level, their species are often different (Lee et al. 2010;Guan et al. 2011;Jung et al. 2011;Kim et al. 2011c;Jung et al. 2013;Jeong et al. 2014). A recent culture-dependent study on the kimchi bacterial community revealed the top five major fermenting bacteria: Leuconostoc (Leuc) mesenteroides, L. citreum, Lactococcus (L) lactis, Weissella (W) koreensis, Bacillus (B) subtilis, and Lactobacillus (L) sakei (Lee et al. 2010). ...
... Comparison of the two methods for bacterial community analysis showed that even though major bacterial communities are highly similar at the genus level, their species are often different (Lee et al. 2010;Guan et al. 2011;Jung et al. 2011;Kim et al. 2011c;Jung et al. 2013;Jeong et al. 2014). A recent culture-dependent study on the kimchi bacterial community revealed the top five major fermenting bacteria: Leuconostoc (Leuc) mesenteroides, L. citreum, Lactococcus (L) lactis, Weissella (W) koreensis, Bacillus (B) subtilis, and Lactobacillus (L) sakei (Lee et al. 2010). However, metagenomic analysis of kimchi showed that the top five major fermenting bacteria were L. mesenteroides, L. citreum, L. sakei, L. casei, W. paramesenteroides, and L. lactis (Jung et al. 2011), indicating that the major bacteria of the bacterial community in kimchi are almost similar but slightly different at the Weissella species level between the two community analysis methods. ...
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... Draw the difference between Korean and Chinese kimchi for future use in the confirmation of kimchi origin (Lee, Cho, Han, & Lee, 2010). ...
Chapter
This chapter focuses on probiotic microorganisms. It firstly summarizes the common microbial groups in food fermentation and summarizes the representative fermented food produced by the metabolic activities of microorganisms. Then it describes the main probiotic microorganisms in fermented foods. At last, it systematically describes the microorganisms of fermented vegetable food, fermented dairy products, fermented meat and fish products, and fermented grain based on microorganisms and probiotics. This chapter comprehensively discusses the probiotic microorganisms in fermented food such as acetic acid bacteria, nonpathogenic Corynebacterium, Lactobacillus, yeast, and mold. It well demonstrates the relationship between probiotic microorganisms and fermented food, highlighting the huge role of probiotic microorganisms in food production and human health maintenance.
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