• Microbiology and Biotechnology Letters
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• v.44 no.1
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• pp.68-73
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• 2016

Lactic acid bacteria showing both protease activity and the capacity to produce casein phosphopeptide (CPP) were isolated from Korean kimchi, a traditional food made from fermented vegetables. Among the 450 strains of isolated lactic acid bacteria, the strain MG-379 showed high protease activity and the highest ability to produce CPP. Characterization results showed that MG-379 was gram-positive and measured $0.6-0.8{\mu}m$ in diameter. DNA sequencing of MG-379 and comparison with other sequences using BLAST revealed a 100% identity with the sequence of Enterococcus faecalis. However, MG-379 showed a higher CPP-producing ability than E. faecalis KCCM 40450. Accordingly, MG-379 was newly named as E. faecalis MG-379. Amount of free calcium liberated by CPPs was 2227.5 and 1151.6 mg/kg for E. faecalis MG-379 and E. faecalis KCCM (control), respectively.

• Korean Journal of Food Science and Technology
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• v.24 no.5
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• pp.477-481
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• 1992

As a series of fundamental research projects to produce doenjang (Korean fermented soy paste) of better quality, two kinds of doenjang were manufactured from a traditional meju (Korean soy bean koji) and the mixed with Aspergillus oryzae and Bacillus natto, and histological changes in the cell structures of soy bean of the two were reported doenjang samples were observed and compared during the entire period of fermentation processes. Cell walls of the soy bean were ruptured by pressure and heat during the pressure cooking process and some of them were observed to have the ghost-like shapes. Remarkable differences in the plasmolysis of the cytoplasms were observed between the seed coat and the inner part of soy bean. Small vacuoles resulting from the fusion of the glycoprotein globules by protease and from the hydrolysis of the starch granules by amylase were also observed. Penetration of microorganisms was transferred from the seed coat to the inside of soy bean as the fermentation proceeded. Slimy substances were observed on the seed coat and the parenchyma cells of soy bean fermented with the mixed with Aspergillus oryzae and Bacillus natto. Cell walls of soy bean became difficult to stain and they showed unusual, polygonal shapes as the fermentation proceeded. Samples fermented with the mixed with Aspergillus oryzae and Bacillus natto showed more remarkable tendencies than traditional meju.

• Proceedings of the Korean Society of Toxicology Conference
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• 2001.10a
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• pp.89-90
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• 2001

Kimchi is a traditional fermented vegetable food in Korea. There are about 187 varieties of Kimchi, depending on the ingredients and processing methods used, which are different in microbiological, nutritional, and biochemical characteristics. Much attention for Kimchi has been focused on health and life extension. Kimchi is fermented by the microorganisms which are originally present in the raw vegetable substances.(omitted)

• Journal of Microbiology and Biotechnology
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• v.30 no.10
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• pp.1510-1515
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• 2020

Trimethylamine (TMA) is a well-known off-odor compound in fish and fishery products and is a metabolic product of trimethylamine N-oxide (TMAO) generated by the enzymatic action of microorganisms. The off-odor is a factor that can debase the value of fish and fishery products. The present study aimed to remove TMA using lactic acid bacteria (LAB). A total of fifteen isolates exhibiting the TMA reduction efficacy were isolated from Korean traditional fermented foods. Among these isolates, five LAB isolates (Lactobacillus plantarum SKD 1 and 4; Lactobacillus paraplantarum SKD 15; Pediococcus stilesii SKD 11; P. pentosaceus SKD 14) were selected based on their high TMA reduction efficacy. In situ reduction of TMA efficacy by the LAB cell-free supernatant was evaluated using a spoiled fish sample. The results showed effective TMA reduction by our selected strains: SKD1 (45%), SKD4 (62%), SKD11 (60%), SKD14 (59%), and SKD15 (52%), respectively. This is the first study on TMA reduction by the metabolic activity of LAB and in situ reduction of TMA using cell-free supernatant of LAB. The present finding suggests an economically useful and ecofriendly approach to the reduction of TMA.

• Microbiology and Biotechnology Letters
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• v.27 no.3
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• pp.236-245
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• 1999

Andong Soju is a Korean traditional distilled liquor brewed with Nuruk which is cultured with wild microorganisms. To provide useful information for scientific production and systematic quality control of traditional distilled liquor, the effects of mixed culture of the alcoholic yeasts and saccharifying molds isolated from the Nuruk, and mashes on the flavor and sensory characteristics were investigated. Distillate from mashes cocultured with Saccharomyces cerevisiae and Hansenula anomala using Mucor Nuruk was compared with distillate from mashes brewed with Andong Nuruk and with distillate from plant fermented mashes to analyze their flavor characteristics. The volatile flavor compounds in distillates were analyzed by GC and GC-MS using direct injection, solvent extraction, and purge & trap methods. Alcohols such as 3-methyl-1-butanol, 2-methyl-1-propanol, 1-propanol, and 2-phenyl ethanol; aldehydes such as acetaldehyde and 2-furancar-boxaldehyde; esters such as ethyl ester of acetic acid, hexanoic acid, octanoic acid, decanoic acid; alkanes, alkenes, ketone, sulfur, and pyrone compounds were detected. Alcohols were chief components of flavor compounds. No significant difference in overall acceptability test was shown among three experimental groups(p<0.05), but Nuruk-like aroma, Kaoliangchiew-like aroma, sweet taste, and well rounded mouthfeel showed significant differences among them(p<0.05).

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.1
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• pp.109-116
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• 1992

Kimchi is a very popular traditional fermented vegetable in Korea, however, contaminations of $NO_3$, $NO_2$ and nitrosamines in Kimchi were suspected. In this review, ingredients used in manufacturing Kimchi, kinds of Kimchi, microorganisms involved the fermentation and nutritional values of Kimchi are introduced. The quantitated levels of $NO_3$, $NO_2$ and secondary amines in the ingredients of Kimchi, and the changes of the contents of $NO_3$, $NO_2$ and nitrosamines during Kimchi fermentation were shown. The level of $NO_3$ during Kimchi fermentation reduced greatly, and the content of $NO_2$ was also trace amounts. NDMA is a major nitrosamine found in Kimchi, but the levels were trace or not detected.

• Journal of Microbiology and Biotechnology
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• v.34 no.3
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• pp.622-633
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• 2024

For quality standardization, the application of functional lactic acid bacteria (LAB) as starter cultures for food fermentation is a well-known method in the fermented food industry. This study assessed the effect of adding a non-thermally microbial inactivated starter culture to kimchi, a traditional Korean food, in standardizing its quality. In this study, pretreatment based on sterilization processes, namely, slightly acidic electrolyzed water (SAEW) disinfection and ultraviolet C light-emitting diode (UVC-LED) of raw and subsidiary kimchi materials were used to reduce the initial microorganisms in them, thereby increasing the efficiency and value of the kimchi LAB starter during fermentation. Pretreatment sterilization effectively suppressed microorganisms that threatened the sanitary value and quality of kimchi. In addition, pretreatment based on sterilization effectively reduced the number of initial microbial colonies in kimchi, creating an environment in which kimchi LAB starters could settle or dominate, compared to non-sterilized kimchi. These differences in the initial microbial composition following the sterilization process and the addition of kimchi LAB starters led to differences in the metabolites that positively affect the taste and flavor of kimchi. The combined processing technology used in our study, that is, pre-sterilization and LAB addition, may be a powerful approach for kimchi quality standardization.

• Microbiology and Biotechnology Letters
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• v.47 no.3
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• pp.364-371
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• 2019

The use of GRAS microorganisms isolated from fermented foods during amylase production using an economical food-waste medium provides more opportunities to produce amylase with a wider range of applications. Hence, this study aimed to isolate a good amylase-producing fungi from the traditional Indonesian fermented cassava, gatot, and to identify the amylase-producing capability of the isolate in a potato peel waste (PPW) medium. Black-colored fungi isolated from gatot was morphologically identified and the amylase produced was characterized using SDS-PAGE and Native PAGE. The isolate was then grown on PPW medium, and the amylase produced was further characterized. Morphological identification and enzyme characterization revealed that the Aspergillus niger aggregate F isolated from gatot secreted an active extracellular ${\alpha}$-amylase with an optimum pH of 5-6. In conclusion, Aspergillus niger aggregate F isolated from gatot can be used to produce ${\alpha}$-amylase using PPW as a medium.

• KSBB Journal
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• v.26 no.5
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• pp.374-380
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• 2011

Earlier in Korea Kimchi was made in every family and every province has own taste and specialties. These days almost of the Kimchis are manufactured. We collected variable Kimchis, which were made for private use and isolated microorganisms. Some interesting micobial cells were identified and studied for its application as food and drinks. One of them was identified as Lactobacillus sakei KJ123. This strain is known as producing interesting aromatic components during Sakei fermentation like Kimchi in variable conditions. We tried to develop a health beverage with fermentation process. The Cucurbita maxima has been known as a traditional healthy food and variable positive effects on the human body were already reported. In this study we tried to develop a production process for a healthy fermented drink on this substrate with strains originated from Kimchi. Many kinds of lacctobacilli species existed in the fermented food cannot survive in the acidic conditions like human stomach. So we selected resisting strains in this conditions. The survival rate of Lactobacillus sakei cells in the artificial gastric juice and bile acid and other physiological characteristics at the variable conditions have been tested. After fermentation process some sensory tests on the product with panels were tried.

• The Korean Journal of Pesticide Science
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• v.18 no.4
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• pp.383-395
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• 2014

When we investigated seed infestation by fungal pathogens from 51 varieties in 9 crops, the contamination rate of rice and sesame seeds was high. Therefore, to control seed-borne diseases, we obtained extracts from commercial products of Kimchi, Gochujang, Doenjang, Ganjang, Makgeolli and Tohajut and their suppressive effects against seed-borne diseases were studied. In addition, bacterial strains were screened to control rice seed-borne diseases in vitro and in vivo. Among forty food extracts, eleven food-extracts suppressed incidence of seedling rots in vitro and five food extracts increased 8-33% of healthy seedling in the greenhouse. Among 218 isolates from 40 fermented foods, 43 isolates showed high antifungal activity against seven fungal pathogens. When we tested 43 isolates for the reduction of rice seed borne disease, 32 isolates were able to reduce the rice seed borne disease. Among 32 isolates, 17 isolates reduced significantly seedling rot and increased healthy seedlings, the other isolates except for Kc4-2 and Mkl 2-2 increased shoot emergence and the percentage of healthy plants. Thirty isolates with high antifungal activity and suppressive effect against rice seedling rots were identified by 16S rRNA sequencing. Twenty one of thirty isolates were identified as Bacillus spp. Three isolates from Makgeolli were identified as Saccharomyces cerevisiae. B. amyloliquifaciens were isolated from six Korean traditional fermented foods except for Ganjang. B. amyloliquifaciens were majority in the effective bacterial population of Gochujang and Jutgal. Relatively diverse Bacillus species including B. subtilis, B. pumilus, and B. amyloliquificiens were isolated from Kimchi. The selected effective microorganisms from Korean fermented foods founded to be effective for controlling seed-borne diseases of rice in vitro and in the greenhouse. We think that Korean fermented foods and their useful microorganisms can be used as biocontrol agents for suppressing rice seed-borne diseases based on above described results.