Search Results (32)

This study aims to elucidate the genomic characteristics of Bacillus subtilis MGE 2012, a strain isolated from Korean traditional fermented food, meju, which contributes to its high enzyme activity and potential applications. The whole genome sequence of B. subtilis MGE 2012 was assembled using MEGAHIT, annotated using RAST and BLASTKOALA v3.1. Phylogenetic analysis placed MGE 2012 within the Bacillus clade, showing high similarity to B. subtilis NCIB 3610 and B. subtilis ATCC 6051. AntiSMASH analysis identified 14 biosynthetic gene clusters (BGCs) capable of producing various secondary metabolites, including subtilosin, bacillibactin, fengycin, bacilysin, plipastatin, and surfactin. This study provides an overview of the whole genome and secondary metabolite profile of B. subtilis MGE 2012, emphasizing its potential applications in biotechnology. While the primary focus of this study was to explore the genomic characteristics and secondary metabolite profile, future research could delve deeper into genome mining for enzyme activities and their applications. Full article

Background: Traditional fermented soybean foods, acting as potential synbiotics, may help mitigate cognitive impairment associated with amnesia. This study investigated the neuroprotective effects of four kanjang (Korean fermented soy sauce) varieties and their underlying mechanisms. Methods: Male Sprague Dawley rats (n = 70) were divided into seven groups: normal control, scopolamine control, positive control (1 mg/kg bw/day of donepezil), and four scopolamine-treated groups receiving different kanjang varieties (0.5% in high-fat diet). Based on their Bacillus content, the kanjang samples were categorized as traditionally made kanjang (TMK) with high Bacillus (SS-HB), TMK with medium Bacillus (SS-MB), TMK with low Bacillus (SS-LB), and factory-made kanjang (SS-FM). Results: Scopolamine administration disrupted energy, glucose, and water metabolism and impaired memory function (p < 0.05). All kanjang treatments improved insulin sensitivity, reduced inflammation, enhanced glucose tolerance, and decreased visceral fat. SS-MB, SS-HB, and SS-FM increased skeletal muscle mass. They maintained body water homeostasis by suppressing the renin–angiotensin–aldosterone system. Kanjang treatments improved memory function, with SS-FM showing the least significant effects. The treatments reduced neuronal cell death in the hippocampal CA1 region, decreased acetylcholinesterase activity, and increased brain-derived neurotrophic factor mRNA expression. Gut microbiota analysis revealed that kanjang treatments increased Lactobacillaceae and decreased Lachnospiraceae, with SS-HB and SS-LB specifically elevating Ligilactobacillus. Metagenomic analysis demonstrated enhanced glycolysis/gluconeogenesis pathways and enhanced butanoate metabolism while reducing lipopolysaccharide biosynthesis and pro-inflammatory signaling. SS-MB and SS-LB increased intestinal goblet cell counts and the serum butyrate concentration. Conclusions: These findings suggest that kanjang consumption, particularly SS-HB and SS-LB varieties, can ameliorate memory impairment in this murine model through multiple mechanisms: metabolic improvements, enhanced neurotrophic signaling, gut microbiota modulation, and reduced neuroinflammation via gut–brain axis activation. Human clinical trials are warranted to determine if these promising neuroprotective effects translate to clinical applications. Full article

Gochujang, a traditional Korean fermented red pepper paste, is celebrated for its unique spicy and fermented flavor. This natural, whole food offers several health benefits due to the bioactive compounds formed during fermentation and its diverse ingredients. These bioactive compounds have been shown to have anti-cancer properties and anti-inflammatory effects by reducing inflammatory cytokines and suppressing pathways associated with diseases such as colitis and hepatitis. Gochujang has also been shown to help prevent obesity by promoting weight loss, inhibiting fat accumulation, and improving lipid profiles. It has also been shown to aid in the prevention of diabetes by suppressing hepatic glucose production and improving insulin sensitivity. The influence of gochujang on the gut microbiota is remarkable, with the ability to increase beneficial bacteria, improve microbial balance, and alleviate metabolic disorders. The primary agents responsible for these effects are capsaicin, fermentation by-products, and other bioactive compounds. The fermentation process, driven by microorganisms, enhances the nutritional and functional properties of gochujang, strengthening its health-promoting potential. This paper provides a comprehensive review of gochujang’s historical background, production methods, the role of microorganisms in fermentation, and its functional properties, emphasizing its value as a functional food for overall health improvement. Full article

The microbial community of a soy sauce is one of the most important factors in determining the sensory characteristics of that soy sauce. In this study, the microbial communities and sensory characteristics of twenty samples of Korean soy sauce (ganjang) were investigated using shotgun metagenome sequencing and descriptive sensory analysis, and their correlations were explored by partial least square (PLS) regression analysis. The metagenome analysis identified 1332 species of bacteria, yeasts, molds, and viruses across 278 genera, of which Tetragenococcus, Bacillus, and Enterococcus accounted for more than 80% of the total community. In the fungal community, Zygosaccharomyces rouxii, Candida versatilis, Rhodotorula taiwanensis, Debaryomyces hansenii, and Aspergillus oryzae were dominant, while the viral community consisted entirely of bacteriophages, with Bacillus phages SIOphi accounting for 93%. According to the results of the PLS analysis, desirable sensory characteristics, such as umami, sweet, and roasted soybean, as well as preference, were associated with Tetragenococcus, Lysinibacillus, Enterococcus, Staphylococcus, Lactobacillus, Pediococcus, and Weissella. The musty flavor, which is a typical property of traditional fermented foods, was related to Halomonas and Psychrobacte, while the bitter, acrid taste and sour smell were closely associated with Chromohalobacter. The results of this study provide comprehensive information on the microbial community of ganjang and may be used to select starter cultures for soy sauces. Full article

Hair growth is crucial for physiological functions and psychological well-being, leading to an increasing demand for research in this area. While low-molecular ginsenosides have been shown to promote hair growth in mice, studies on their effects are limited, and there is a lack of research examining the impact of ginsenoside fermentation products derived from lactic acid bacteria. This study investigated the hair-growth-promoting effect of fermented ginsenoside by fermentation of Levilactobacillus brevis THK-D437, which was isolated from the traditional Korean fermented food kimchi and features high β-glucosidase activity. In the cell-based MTT assay, the proliferation rate was increased by 25% in the fermented ginsenoside-treated group on human hair dermal papilla cells (HHDPCs). In the alopecia mouse model study (C57BL/6 mouse model), enhanced hair growth was observed in the fermented ginsenoside-treated mouse groups. Tissue histological analyses showed that the number of hair follicles and the thickness of the epidermis, respectively, were increased in the fermented ginsenoside-treated mouse groups. These results suggested that fermented ginsenoside has a promoting effect on hair growth and a retarding effect on the catagen stage. Therefore, fermented ginseng products might be a new potential therapeutic candidate for promoting hair growth. Full article

Non-alcoholic fatty acid disease (NAFLD) is caused by a build-up of fat in the liver, inducing local inflammation and fibrosis. We evaluated the effects of probiotic lactic acid-generating bacteria (LAB) derived from a traditional fermented beverage in a mouse model of NAFLD. The LAB isolated from this traditional Korean beverage were screened using the human hepatic cell line HepG2, and Lactocaseibacillus paracasei HY7207 (HY7207), which was the most effective inhibitor of fat accumulation, was selected for further study. HY7207 showed stable productivity in industrial-scale culture. Whole-genome sequencing of HY7207 revealed that the genome was 2.88 Mbp long, with 46.43% GC contents and 2778 predicted protein-coding DNA sequences (CDSs). HY7207 reduced the expression of lipogenesis and hepatic apoptosis-related genes in HepG2 cells treated with palmitic acid. Furthermore, the administration of 10⁹ CFU/kg/day of HY7207 for 8 weeks to mice fed an NAFLD-inducing diet improved their physiologic and serum biochemical parameters and ameliorated their hepatic steatosis. In addition, HY7207 reduced the hepatic expression of genes important for lipogenesis (Srebp1c, Fasn, C/ebpa, Pparg, and Acaca), inflammation (Tnf, Il1b, and Ccl2), and fibrosis (Col1a1, Tgfb1, and Timp1). Finally, HY7207 affected the expression of the apoptosis-related genes Bax (encoding Bcl2 associated X, an apoptosis regulator) and Bcl2 (encoding B-cell lymphoma protein 2) in the liver. These data suggest that HY7207 consumption ameliorates NAFLD in mice through effects on liver steatosis, inflammation, fibrosis, and hepatic apoptosis. Thus, L. paracasei HY7207 may be suitable for use as a functional food supplement for patients with NAFLD. Full article

Foods that help improve menopausal syndrome are being studied worldwide. Doenjang is a traditional Korean fermented soybean food with potential health benefits for menopausal women. In this clinical trial using Doenjang, we aimed to compare the effectiveness of traditional Doenjang and commercial Doenjang in menopausal women. Furthermore, we compared whether Doenjang has a better effect if the number of beneficial microbes is higher. The analyses included the following groups: traditional Doenjang containing either a high dose (HDC; n = 18) or low dose (LDC; n = 18) of beneficial microbes and commercial Doenjang (CD; n = 20). The Kupperman index and hematological changes were examined before and after the use of Doenjang pills. The effects of Doenjang on obesity and body composition were studied before and after ingestion. Lastly, the microorganisms and short-chain fatty acid changes in the stool were compared. The Kupperman index decreased after Doenjang consumption in all three groups, with the greatest decrease in the LDC group. Only the groups that took traditional Doenjang pills exhibited reduced LDL cholesterol. No changes in obesity and inflammation-related indicators were observed. The number of Firmicutes, associated with obesity, decreased in the CD group but the numbers of Bacteroidetes increased in the HDC and CD groups. Thus, traditional Doenjang is more effective in alleviating menopausal syndrome than commercial Doenjang. Further research on the anti-obesity effect or changes in microbiomes and short-chain fatty acids in feces is needed. Full article

In this review, we explore the immunomodulatory properties of Korean foods, focusing on ginseng and fermented foods. One notable example is Korean red ginseng, known for its immune system-regulating effects attributed to the active ingredient, ginsenoside. Ginsenoside stimulates immune cells, enhancing immune function and suppressing inflammatory responses. With a long history, Korean red ginseng has demonstrated therapeutic effects against various diseases. Additionally, Korean fermented foods like kimchi, doenjang, chongkukjang, gochujang, vinegar, and jangajji provide diverse nutrients and bioactive substances, contributing to immune system enhancement. Moreover, traditional Korean natural herbs such as Cirsium setidens Nakai, Gomchwi, Beak-Jak-Yak, etc. possess immune-boosting properties and are used in various Korean foods. By incorporating these foods into one’s diet, one can strengthen their immune system, positively impacting their overall health and well-being. Full article

Nitric oxide (NO) is a free radical associated with physiological functions such as blood pressure regulation, cardiovascular health, mitochondrial production, calcium transport, oxidative stress, and skeletal muscle repair. This study aimed to isolate Latilactobacillus curvatus strains with enhanced NO production from the traditional Korean fermented food, jangajji, and evaluate their probiotic properties for industrial purposes. When cells were co-cultured with various bacterial stimulants, NO production generally increased, and NO synthesis was observed in the range of 20–40 mg/mL. The selected strains of Lat. curvatus were resistant to acid and bile conditions and with variable effectiveness (1–14%) in adhering to Caco-2 cells. Most bacterial strains can inhibit the growth of various pathogens. In addition, they are capable of reducing cholesterol levels via assimilation of cholesterol at 10–50%. Among the selected NO synthases from Lat. curvatus strains, the strain JBCC38 showed the highest capacity to scavenge ABTS (30.1%) and DPPH radicals (39.4%). Moreover, these strains exhibited immunomodulatory properties. The production of TNF-α and IL-6 in the macrophages treated with various bacterial stimulants was induced in all the selected strains. Full article

The aim of this study was to identify new potential probiotics with improved storage stability and to evaluate their efficacy and safety. Sixty lactic acid bacteria strains were isolated from Korean traditional fermented foods, and their survival was tested under extreme conditions. Lactobacillus plantarum HY7718 (HY7718) showed the greatest stability during storage. HY7718 also showed a stable growth curve under industrial conditions. Whole genome sequencing revealed that the HY7718 genome comprises 3.26 Mbp, with 44.5% G + C content, and 3056 annotated Protein-coding DNA sequences (CDSs). HY7718 adhered to intestinal epithelial cells and was tolerant to gastric fluids. Additionally, HY7718 exhibited no hemolytic activity and was not resistant to antibiotics, confirming that it has probiotic properties and is safe for consumption. Additionally, we evaluated its effects on intestinal health using TNF-induced Caco-2 cells. HY7718 restored the expression of tight junction proteins such as zonular occludens (ZO-1, ZO-2), occludin (OCLN), and claudins (CLDN1, CLDN4), and regulated the expression of myosin light-chain kinase (MLCK), Elk-1, and nuclear factor kappa B subunit 1 (NFKB1). Moreover, HY7718 reduced the secretion of proinflammatory cytokines such as interleukin-6 (IL-6) and IL-8, as well as reducing the levels of peroxide-induced reactive oxygen species. In conclusion, HY7718 has probiotic properties, is safe, is stable under extreme storage conditions, and exerts positive effects on intestinal cells. These results suggest that L. plantarum HY7718 is a potential probiotic for use as a functional supplement in the food industry. Full article

In the present study, a total of eight Enterococcus faecium (OQ940301, OQ940302, OQ940303, OQ940304, OQ940305, OQ940308, OQ940309, and OQ940310) were isolated from soybean paste, a traditional Korean fermented food, and evaluated for their probiotic properties. The results showed that all the E. faecium strains survived in simulated human gastrointestinal conditions (4.1–5.59 log₁₀ CFU/mL). In addition, the range of auto-aggregation was 5–25%, the hydrophobicity was around 94%, and it exhibited significant co-aggregation ability with Salmonella enterica and Staphylococcus aureus. However, all the isolates were shown to be resistant to Gentamycin. The bacterial cell-free supernatant showed antibacterial activity against S. enterica, Escherichia coli, Bacillus cereus, Listeria monocytogenes, and S. aureus. Furthermore, E. faecium exhibited potent anti-oxidant activity by scavenging 2,2′-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) free radicals. In addition, safety was confirmed by evaluating the hemolytic activity in blood agar; none of the bacterial isolates showed hemolysis. These results demonstrated that E. faecium (OQ940301 and OQ940309) isolated from soybean paste showed a higher probiotic potential. Full article

The Enterococcus faecium strain DMEA09 was previously isolated from traditional Korean fermented meju. The objective of the current study was to investigate the traits of E. faecium strain DMEA09 as a starter candidate, focusing on its safety and technological properties. Regarding its safety, the DMEA09 strain was found to be sensitive to nine antibiotics (ampicillin, chloramphenicol, erythromycin, gentamicin, kanamycin, streptomycin, tetracycline, tylosin, and vancomycin) by showing lower minimum inhibitory concentrations (MICs) than the cut-off values suggested by the European Union Food Safety Authority for these nine antibiotics. However, its MIC value for clindamycin was twice as high as the cut-off value. A genomic analysis revealed that strain DMEA09 did not encode the acquired antibiotic resistance genes, including those for clindamycin. The DMEA09 strain did not show hemolysis as a result of analyzing α- and β-hemolysis. It did not form biofilm either. A genomic analysis revealed that strain DMEA09 did not encode for any virulence factors including hemolysin. Most importantly, multilocus sequence typing revealed that the clonal group of strain DMEA09 was distinguished from clinical isolates. Regarding its technological properties, strain DMEA09 could grow in the presence of 6% salt. It showed protease activity when the salt concentration was 3%. It did not exhibit lipase activity. Its genome possessed 37 putative protease genes and salt-tolerance genes for survivability under salt conditions. Consequently, strain DMEA09 shows safe and technological properties as a new starter candidate. This was confirmed by genome analysis. Full article

To understand the biological roles of Pediococcus pentosaceus strains as probiotics isolated from the traditional Korean fermented food, Jangajji, Pediococcus pentosaceus was selected based on its high cinnamoyl esterase (CE) and antioxidant activities. The acid and bile stability, intestinal adhesion, antagonistic activity against human pathogens, cholesterol-lowering effects, and immune system stimulation without inflammatory effects were evaluated. Nitric oxide (NO) levels were measured in co-culture with various bacterial stimulants. Fermentation ability was measured by using a broccoli matrix and the sulforaphane levels were measured. Resistance to acidic and bilious conditions and 8% adherence to Caco-2 cells were observed. Cholesterol levels were lowered by 51% by assimilation. Moreover, these strains exhibited immunomodulatory properties with induction of macrophage TNF-α and IL-6 and had microstatic effects on various pathogens. Co-culture with various bacterial stimulants resulted in increased NO production. Fermentation activity was increased with the strains, and higher sulforaphane levels were observed. Therefore, in the future, the applicability of the selected strain to broccoli matrix-based fermented functional foods should be confirmed. Full article

Doenjang and ganjang are traditional, Korean fermented foods. They are manufactured by fermenting jangs, either through the traditional natural fermentation, using straw, or the commercial inoculating starter cultures. However, both Bacillus cereus and aflatoxins have been detected in jangs, compromising their safety. Aflatoxins have been detected on numerous occasions. However, studies are yet to be conducted on whether these safety issues differ depending on the manufacturing method. In this study, we evaluated whether the manufacturing methods of doenjang and ganjang alter their safety. Samples of traditional and commercial doenjang and ganjang were analyzed for aflatoxin and B. cereus contamination. Microbiome taxonomic profiling was performed to assess microbial composition. The experimental methodology involved sample collection from various stages of production, including the use of starter cultures and natural fermentation processes. Aflatoxin levels were determined using regulatory limits, and B. cereus content was evaluated against specific thresholds. Aflatoxins were detected in both traditional and commercial doenjang and ganjang, with either the total aflatoxin (15 μg/kg) or aflatoxin B1 (10 μg/kg) exceeding the regulatory limits. However, ochratoxin A was not detected in any of the samples. B. cereus was detected in some samples, within the regulatory limit (4 log CFU/g), and was not influenced by the manufacturing method. Analysis at the production stage showed that aflatoxin increased alongside the fermentation time in traditional doenjang. However, in ganjang, no significant differences were associated with the fermentation period. When using starter cultures, the fermentation period did not affect the toxin level in both foods. Both methods showed lower aflatoxin content in the initial doenjang and ganjang samples than in meju. B. cereus was not detected in either method, as its content decreased over the fermentation period. Microbiome taxonomic profiling confirmed that even when using starter cultures, B. cereus was not a dominant species and was considerably affected by the environment. Staphylococcus aureus and Pseudomonas, pathogenic in nature, were detected in products manufactured using the traditional method; hence, the potential risk of this method was higher than that of the commercial method. The experimental methodology employed in this study contributes to understanding the microbial composition and toxin contamination levels in doenjang and ganjang, contributing to the overall knowledge of their safety and quality control. Full article

Cheonggukjang is a traditional Korean fermented soybean food with potential health benefits. For this reason, Cheonggukjang is consumed in the form of pills in addition to being used as a food ingredient. There are few clinical studies that have evaluated changes in various health indicators through blood and stool tests before and after consumption of Cheonggukjang. In this study, symptoms and hematological changes were analyzed before and after the intake of traditional Cheonggukjang pills containing high-dose (n = 19) or low-dose (n = 20) beneficial bacteria and commercial Cheonggukjang pills (n = 20). Anti-obesity effects and body composition changes were determined before and after Cheonggukjang consumption. Lastly, the changes in microorganisms and short-chain fatty acids in the stool were compared. No changes in obesity and inflammation-related indicators were observed before and after Cheonggukjang consumption. The Firmicutes/Bacteroidetes ratio, associated with obesity, decreased in all three groups after Cheonggukjang consumption, but no statistical significance was indicated. Cheonggukjang contained various BAs, but they did not adversely affect symptoms and hematological changes in the participants. BAs generated during the manufacturing process of Cheonggukjang did not have any adverse effects in this randomized, double-blind clinical trial. Further research is needed in future concerning the anti-obesity effect or regarding changes in the microbiome and short-chain fatty acids in feces. Full article