• Journal of Microbiology and Biotechnology
• /
• v.16 no.1
• /
• pp.68-76
• /
• 2006

Despites many attempts to explore the microbial diversity in kimchi fermentation, the predominant flora remains controversial to date. In the present study, major lactic acid bacteria (LAB) were investigated in Chinese cabbage kimchi in the early phase of fermention. For the samples over pH 4.0, viable cell counts of Leuconostoc and Pediococcus were $10^6\;cfu/ml$ and below $10^2\;cfu/ml$, respectively, and 20 isolates out of 172 were subjected to a biochemical identification (API 50 CH kit) as well as molecular-typing methods including ITSPCR with a RsaI digestion and 16s rRNA gene sequence analysis for species confirmation. Seven isolates were nicely assigned to Lb. brevis, 6 to Leuconostoc spp. (2 mesenteroides, 2 citreum, I carnosum, I gasicomitatum), 4 to Weissella (3 kimchii/cibaria, 1 hanii) and 2 to other Lactobacillus spp. (1 farciminis, 1 plantarum). On the other hand, the biochemical identification data revealed 9 strains of Lb. brevis, 6 strains of Leuconostocs,2 strains of Lb. plantarum and 1 strain each of Lb. coprophilus and Lactococcus lactis. However, a single isolates, YSM 16, was not matched to the ITS-PCR database constructed in the present study. Two Lb. brevis strains by API 50 CH kit were reassigned to W kimchii/cibaria, Lb. coprophilus or W hanii, respectively, judging from the results by the above molecular typing approaches. As a whole, the identification data obtained by the biochemical test were different from those of ITS-PCR molecular method by about $63\%$ at genus-level and $42\%$ at species-level. The data by the ITS-PCR method conclusively suggest that predominant LAB species is probably heterolactic Lb. brevis, followed by W kimchii/cibaria, Leuc. mesenteroides, and Leuc. citreum, in contrast to the previous reports [3] that Leuc. mesenteroides is the only a predominant species in the early phase kimchi fermentation.

• Food Science and Preservation
• /
• v.23 no.5
• /
• pp.718-726
• /
• 2016

Sweet pumpkin paste (SPP) was fermented by Leuconostoc mesenteroides SM at $25^{\circ}C$ for 3 days for enhancing its physicochemical properties. SPPs with 5%, 10%, and 15% solid contents (SC) were fortified with 20% sucrose and 0.5% yeast extract. The unfermented SPP with 15% SC indicated L, a, and b color values of 25.02, 4.66, and 13.35, respectively, and a consistency index of $48.6Pa{\cdot}s^n$. During the 3 days of fermentation, both the a and b color values decreased slightly, whereas the consistency index increased to $188.8Pa{\cdot}s^n$, giving the fermented product a pudding-like consistency. This fermented SPP (15% SC) showed the highest acid production and viable cell counts among samples, indicating pH 3.85, 1.30% acidity and $9.2{\times}10^8CFU/mL$ respectively. The added sucrose was completely utilized after 1 day of fermentation. After 3 days, the insoluble and soluble dextran contents were 8.9% and 4.5%, respectively. Furthermore, the contents of mannitol and fructose were 3.11% and 1.76%, respectively. Regarding the sensory evaluation, this fermented sample also indicated the highest color, taste and texture scores, and was the overall preferred sample. In conclusion, the fermented SPP with 15% SC was carotinoid-rich a wholesome pumpkin-based product that is rich in probiotics and lactic bacteria-produced mannitol and dextran, which gave the product an acceptable viscous pudding-like consistency and good organoleptic properties.

• Journal of Microbiology and Biotechnology
• /
• v.23 no.12
• /
• pp.1717-1725
• /
• 2013

Traditional soybean paste from Shandong Liangshan and Tianyuan Jiangyuan commercial soybean paste were chosen for analysis and comparison of their bacterial and fungal dynamics using denaturing gel gradient electrophoresis and 16S rRNA gene clone libraries. The bacterial diversity results showed that more than 20 types of bacteria were present in traditional Shandong soybean paste during its fermentation process, whereas only six types of bacteria were present in the commercial soybean paste. The predominant bacteria in the Shandong soybean paste were most closely related to Leuconostoc spp., an uncultured bacterium, Lactococcus lactis, Bacillus licheniformis, Bacillus spp., and Citrobacter freundii. The predominant bacteria in the Tianyuan Jiangyuan soybean paste were most closely related to an uncultured bacterium, Bacillus licheniformis, and an uncultured Leuconostoc spp. The fungal diversity results showed that 10 types of fungi were present in the Shandong soybean paste during the fermentation process, with the predominant fungi being most closely related to Geotrichum spp., an uncultured fungal clone, Aspergillus oryzae, and yeast species. The predominant fungus in the commercial soybean paste was Aspergillus oryzae.

• The Journal of the Korea Contents Association
• /
• v.22 no.1
• /
• pp.646-655
• /
• 2022

This study was conducted to investigate the quality characteristics of Kimchi during fermentation and storage according to containers with native plant extract. The containers used in the experiment were antimicrobial polypropylene containers(KAPP) developed with the addition of native plant extracts, and it was tested by comparing the microbial changes and sensory characteristics of the existing commercial containers, such as polypropylene containers(KPP), stainless steel containers(KST), and porcelain containers(KPC). Change in total microbial cell were similar for each container. Coliform maintained the lowest level from 15 days after storage to 50 days. Leuconostoc spp. and Lactobacillus spp. showed a rapid increase in all four storage containers until the 15th day of storage and then decreased. The KAPP container maintained its highest level. The sensory evaluation was carried out on Kimchi optimal condition(storage 40 days). The sensory scores of KAPP were generally higher than those of other experimental samples in characteristics of appearance, odor, taste and overall preference. As a result, KAPP container has an excellent antibacterial effect as compared with the three commercially available storage containers, is effective for fermentation of lactic acid.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.27 no.6
• /
• pp.1059-1064
• /
• 1998

Fermented beverage using lactic acid bacteria isolated from kimchi was investigated. Lactic acid bacteria KL 1, KD 6, KL 4 strains from kimchi, or obtained Lactobacillus acidophilus, Lactobacillus plantarum, Leuconostoc mesenteroides with and without yeast(Saccharomyces cerevisiae) were inoculated in fruit vegetable juice for single and mixed culture fermentation. During the fermentation by bacterial strain and yeast for 1~3 days at 30oC, various fermentation behaviors were observed. The growth rate of mixed culture of KL 1 and yeast was higher than that of single culture by KL 1 alone during the fermentation. The amount of organic acid produced by the mixed culture fermentation of KL 1 and yeast was 0.82%(3 day) or 0.58%(1 day) and with the final pH of 3.3(3 day) or 4.2(1 day). These mixed culture systems of isolated strains or other bacterial strains had almost similar results of growth rate and acid production. Among several bacterial strains, KL 1 was suitable for the mixed culture fermentation with yeast in terms of desirable fermentation behavior and organoleptical quality. The selected strain, KL 1 was identified as Leuconostoc spp. through the series of tests on carbohydrate fermentation and biochemical characteristics.

• Food Science of Animal Resources
• /
• v.39 no.4
• /
• pp.677-685
• /
• 2019

Five Leuconostoc strains (CM17, CM19, PM30, PM32, and PM36) previously isolated from Indian meat showed promising antimicrobial activity against food pathogens in screening assay. This study evaluates the efficacy of these isolates against Escherichia coli Microbial Type Culture Collection and Gene Bank (MTCC) 443 and Listeria monocytogenes (MTCC 657) in spinach leaves. Challenge studies were conducted by inoculating E. coli and L. monocytogenes at 6 to 7 $Log_{10}CFU/g$ of the leaves respectively and treating them with cell free supernatant (CFS) of 48 h cultures of the isolates. The samples were stored at $4^{\circ}C$ and analyzed over a period of 5 d. The study was conducted in triplicates and statistical analysis was carried out using one-way Anova. The counts of the pathogens did not increase over the 5 d period in the control samples, without any treatment. Whereas in the case of CFS treatments, significant reduction (p<0.05) was observed in both E. coli and L. monocytogenes from 1 to 5 d with all the 5 strains as compared to the control. The counts of Listeria dropped by 0.5 to 1 log by 5 d, with PM 36 showing the highest reduction (1 log). In the case of E. coli, 1.1 to 1.5 log reduction was observed by 5 d, with again PM 36 showing the highest reduction (1.5). The overall results indicate that the isolates (specifically PM36) not only showed efficacy in in vitro studies but are also proved to be effective in food matrix making them potential clean label antimicrobial alternatives for food application.

• Microbiology and Biotechnology Letters
• /
• v.32 no.3
• /
• pp.249-255
• /
• 2004

Chinese cabbage ('Baechu') Kimchi was fermented at the three different temperatures right after it was prepared. Samples were taken everyday for measuring bacterial populations, pH, and titratable acidity through the whole periods of fermentation up to 50 days. pH values and developed acidity were significantly affected by the fermenting temperatures of 4, 10, and $20^{\circ}C$, suggesting that different bacterial flora has been established by the temperatures exposed. The modified MRS agar containing vancomycin (300 $\mu$g/mL) was used for isolating the vancomycin-resistant LAB strains and 127 isolates were finally obtained. Of the LAB isolates, 13 isolates were subjected to the identification experiments based on the biochemical characteristics and the molecular-typing approach, an ITS-PCR, whether they belong to the genus Leuconostoc or not. The data obtained from API 50 CHL kit resulted that six isolates were identified as the members of Leuconostoc and six as Lactobacillus brevis strains except for a single isolate YKI 30-0401, which was not able to be identified because its biochemical traits were not matched to the database of API 50 CHL kit. It was noted that some isolates were distinct in a couple of some biochemical characteristics compared with those of the reference Leuconostoc species. To overcome the limitations experienced in the commercial identification products above, an ITS-PCR experiment was also conducted for the isolates, resulting that eight isolates belong to Leu. mesenteroides ssp. mesenteroides or dextranicum with a single band of 564 bp, and four to L. brevis strains. The ITS-PCR profiles clearly differentiated the closely-related LAB isolates for which same results were obtained by the biochemical method. This molecular approach, however, failed to produce the amplicons for the YKI 20-1003, leaving the strain unidentified. Judging from the identification data obtained in the Kimchi fermented at $4^{\circ}C$ or $10^{\circ}C$, Leuconostoc spp. including Leu. mesenteroides/dextranicum were likely predominant species in the earlier stage and L. brevis occurred at the high level through the whole period. By contrast, L. brevis, as one of the major flora, possibly lead the fermentation from the beginning in the Kimchi fermented at $20^{\circ}C$.}C$.

• Journal of Life Science
• /
• v.33 no.11
• /
• pp.915-922
• /
• 2023

Lactic acid bacteria (LAB) are widespread in a variety of environments including fermented dairy products, gastroinstetinal and urogenital tracts of human and animals, plant, soil and water. Leuconostoc mesenteroides DB3 was detected by the strongest antibacterial activities among 24 Leuconostoc strains isolated from Camellia japonica flowers. Acid tolerance of L. mesenteroides DB3 existed up to pH 2.5, but the resistance did not show at pH 2.0, which relatively excellent acid resistance existed. Bile acid tolerance was very stable within the test range to 1.2%. L. mesenteroides DB3 exhibited the optimal growth at 30℃, and showed a slight slow growth when compared with L. mesenteroides KCTC3505, which reached a stationary phase at 18 hr. The pH was changed along with the growth curve, but was maintained above pH 3.98. L. mesenteroides DB3 had higher initial antibacterial activities when compared to L. mesenteroides KCTC3505, but it showed similar activities with the standard strain after the latter part of the logarithmic growth phase. Although lactic acid production in L. mesenteroides DB3 was induced by lower amount in the initial part to the standard strain, it was exhibited by similar amounts after the late logarithmic growth phase. Muicin adhesion of L. mesenteroides DB-3 maintained superior to L. mesenteroides KCTC3505. Both strains showed excellent emulsification ability for kerosene. In summary, we evaluate that L. mesenteroides DB-3 has a high potential for application as probiotics owing to its excellent antibacterial activity, acid resistance, bile acid resistance, and muicin adhesion.

• Food Science and Preservation
• /
• v.30 no.6
• /
• pp.1082-1094
• /
• 2023

The purpose of this study was to examine the characteristics of Leuconostoc spp. isolated from radish kimchi and to investigate the potential for the use of functional ingredients by evaluating enzymatic characteristics, safety, and immune-enhancing effects among the isolates, including Lactobacillus rhamnosus ATCC53103 (LGG) as a control strain. All test strains exhibited β-glucosidase enzyme activity that releases β-1,4 sugar chain bonds. In addition, as a result of antibiotic resistance assay among the isolates, MIC values on 8 antibiotics were below compared to the EFSA standard, and hemolytic experiments confirmed that all showed gamma hemolysis without hemolytic ability. As a result of the antibacterial activity experiment, the Leu. mesenteroides K2-4 strain showed a higher activity than LGG against Bacillus cereus and Staphylococcus aureus. Additionally, the activity of the NF-kB/AP-1 transcription factor increased when the isolates were treated in macrophage RAW cells. These results were related to increasing the high mRNA expression levels on TNF-α and IL-6 by Leu. mesenteroides K2-4 strain to be treated at low concentration. Consequently, we suggest that it will be useful as a candidate for functional food ingredients.

• Korean Journal of Food Science and Technology
• /
• v.41 no.6
• /
• pp.644-651
• /
• 2009

This study was conducted to investigate the effects of steeping periods and temperatures of waxy rice on the microflora and enzyme activities of steeping water and waxy rice, as well as on the microscopic structures of waxy rice during the preparation of gangjung. When the steeping water was 15 and $35^{\circ}C$, yeast and lactic acid bacteria were the major microflora after 1 day. After 11 days, Lactobacillus spp. were the major bacteria, while Bacillus spp. were the primary microflora after 21 days. At $25^{\circ}C$ the primary species were Bacillus spp., Leuconostoc spp., and Bacillus spp. after 1, 11 and 21 days, respectively. The $\alpha$-amylase activity of steeping water increased proportionally with the increase of temperature and period, while the protease activity tended to increase for 11 days, but decreased at 21 days. The enzyme activities of the steeped waxy rice, especially the $\alpha$-amylase activity, decreased with higher steeping temperature, while the $\beta$-amylase and glucoamylase activity remained constant for up to 21 days. Observation using scanning electron microscopy indicated that intracellular cleavage of steeped waxy rice endosperm resulted in a rough surface morphology due to the exposure of polygonal starch granules. Tiny pinholes on the surface of waxy rice starch granules were also observed after steeping for 11 days.