• Microbiology and Biotechnology Letters
• /
• v.48 no.4
• /
• pp.455-462
• /
• 2020

Leuconostoc mesenteroides CJNU 0705 was isolated from a breast milk sample and identified by 16S rRNA gene sequencing and confirmed by its ability to produce dextran from tryptic soy agar plates supplemented with 2% sucrose. This strain can absorb various heavy metals including lead (Pb) and cadmium (Cd) which are both found in fine dust and have been shown to be harmful to human skin. In addition, Leu. mesenteroides CJNU 0705 has demonstrated antimicrobial activity against Propionibacterium acnes, the primary causative agent of acne. Given these traits it was natural to evaluate the use of this strain in the fermentation of several natural extracts from green tea, carrot, annual wormwood, parsley, broccoli, and corn silk, which are known to improve skin health, to see if it could increase their dextran content when supplemented with no sucrose, 2% sucrose, or 2% sucrose and 3% yeast extract. The extracts supplemented with both yeast and sucrose were found to produce the most dextran, which was confirmed by the scanning electron microscope (SEM) images. These results suggest that Leu. mesenteroides CJNU 0705 and its fermented natural extracts could be used as functional materials for improving human skin health.

• Journal of Life Science
• /
• v.31 no.8
• /
• pp.761-770
• /
• 2021

In this study, the optimal medium composition for enhancing protease production was established by the Bacillus strain isolated from Makgeolli, a traditional fermented food, using the response surface methodology. B. amyloliquefaciens SRCM115785 was selected as the protease producer by productivity analysis and identified by 16S rRNA gene sequencing. Plackett-Burman design (PBD) was introduced to analyze the effect of each component on protease production among the 11 selected medium components. As a result, glucose, yeast extract, and beef extract were finally selected as factors for enhancing protease production. Central composite design (CCD) analysis was designed as a method to determine the optimal concentration of each component for protease production and the concentration of each medium composition for maximum protease production was predicted to glucose 6.75 g/l, yeast extract 12.42 g/l and beef extract 17.48 g/l. The suitability of the experimental model was proved using ANOVA analysis and as a result of quantitative analysis to prove this, the amount of increase was 230.47% compared to the LB medium used as a control. Through this study, the optimization of medium composition for enhancing protease production was established, and based on this, it is expected that it can be efficient use of protease as an industrial enzyme.

• Korean Journal of Food Science and Technology
• /
• v.54 no.2
• /
• pp.203-208
• /
• 2022

Gluten is an insoluble protein present in cereals such as wheat. Gluten consumed through food is not digested and accumulates in the body; this has been linked to digestive discomfort, irritation, and various digestive disorders, including intestinal inflammation. In this study, the Lactobacillus paracasei strain GLU70, which exhibits a glutendegrading ability, was isolated from salted seafood. At a pH of 3.0, GLU70 showed a survival rate of approximately 84%, and at 0.3% oxgall, it showed a survival rate of approximately 53%. When the culture supernatant collected after 12 h of incubation was added to flour dough, approximately 50% gluten degradation was observed. Moreover, among several probiotic isolates exhibiting proteolytic activity selected to assess the gluten-degrading ability, GLU70 showed superior results regardless of the dough fermentation temperature. Although further research is required, GLU70 is expected to be of value in manufacturing gluten-reduced products and the food industry as an ingredient or additive.

• Journal of Mushroom
• /
• v.19 no.4
• /
• pp.316-321
• /
• 2021

Ligninolytic enzymes were produced by Pleurotus ostreatus No.42, cultivated in a new kind of bioreactor that has a rotating draft tube with a helical ribbon. Maximum laccase (Lac) production (about 8,200 U/bioreactor) was reached after 3 days of incubation, then production decreased. Production of manganese peroxidase (MnP) in this fermenter reached a maximum level of about 8,400 U/bioreactor after 6 days of incubation. Lignin peroxidase (LiP) was not detected under these growth conditions. These results indicate that the rotary draft tube bioreactor (RTB) is compatible with large scale production of ligninolytic enzymes. MnP produced under these fermentation conditions was purified via a multistep process that included chromatography on Sepharose CL-6B, prep grade Superdex 75, and Mono-Q. This major isoenzyme was confirmed to have an apparent molecular weight of 36,400 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and its isoelectric point (IEF) was determined to be 3.95. N-terminal sequencing of the major isoenzyme from this fermentation was identical to that reported for an MnP3 isoenzyme isolated under different cultivation conditions, including stationary and shaking culture.

• Journal of Life Science
• /
• v.33 no.1
• /
• pp.73-81
• /
• 2023

In the present study, we prepared hot water extracts and the subsequent organic solvent fractions of methanol extracts of Houttuynia cordata (HC) and Lespedeza cuneata (LC), and investigated their anti-inflammatory effects on lipopolysaccharide-stimulated RAW264.7 cells. Among the treated samples, hexane, chloroform, and ethyl-acetate fractions of HC and LC inhibited nitric oxide (NO) production in a dose-dependent manner, and decreased inducible nitric oxide synthase (iNOS) protein expression. And, we analyzed the flavonoid contents of the ethyl-acetate fraction of HC and LC, and chose apigenin for the further experiments because apigenin was one of flavonoids commonly found in HC and LC. Apigenin dramatically inhibited NO production in a dose-dependent manner without affecting cell viability and decreased iNOS and cyclooxygenase-2 (COX-2) expression. In addition, apigenin suppressed the phosphorylation of p38 and Jun N-terminal kinase (JNK) indicating that apigenin exerts anti-inflammatory activity via the mitogen-activated protein kinase (MAPK) signaling pathway. Subsequently, we conducted RNA-sequencing analysis to detect differentially expressed genes upon apigenin treatment. Among the down-regulated genes, four cytokine genes (interleukin (IL)-1α, IL-1β, IL-6, and colony stimulating factor 2 (CSF2)) were selected for the further analysis, and the reduction of their expression by apigenin was confirmed with quantitative real-time polymerase chain reaction. Overall, our results suggest that Houttuynia cordata and Lespedeza cuneata have the anti-inflammatory effects and apigenin can be the one of key molecules responsible for their anti-inflammatory activities.

• Nutrition Research and Practice
• /
• v.17 no.4
• /
• pp.682-697
• /
• 2023

BACKGROUND/OBJECTIVES: Tibetan tea is a kind of dark tea, due to the inherent complexity of natural products, the chemical composition and beneficial effects of Tibetan tea are not fully understood. The objective of this study was to unravel the composition of Tibetan tea using knowledge-guided multilayer network (KGMN) techniques and explore its potential antioxidant and hypolipidemic mechanisms in mice. MATERIALS/METHODS: The C57BL/6J mice were continuously gavaged with Tibetan tea extract (T group), green tea extract (G group) and ddH2O (H group) for 15 days. The activity of total antioxidant capacity (T-AOC) and superoxide dismutase (SOD) in mice was detected. Transcriptome sequencing technology was used to investigate the molecular mechanisms underlying the antioxidant and lipid-lowering effects of Tibetan tea in mice. Furthermore, the expression levels of liver antioxidant and lipid metabolism related genes in various groups were detected by the real-time quantitative polymerase chain reaction (qPCR) method. RESULTS: The results showed that a total of 42 flavonoids are provisionally annotated in Tibetan tea using KGMN strategies. Tibetan tea significantly reduced body weight gain and increased T-AOC and SOD activities in mice compared with the H group. Based on the results of transcriptome and qPCR, it was confirmed that Tibetan tea could play a key role in antioxidant and lipid lowering by regulating oxidative stress and lipid metabolism related pathways such as insulin resistance, P53 signaling pathway, insulin signaling pathway, fatty acid elongation and fatty acid metabolism. CONCLUSIONS: This study was the first to use computational tools to deeply explore the composition of Tibetan tea and revealed its potential antioxidant and hypolipidemic mechanisms, and it provides new insights into the composition and bioactivity of Tibetan tea.

• Research in Plant Disease
• /
• v.21 no.4
• /
• pp.297-308
• /
• 2015

In order to control seed-borne diseases, we obtained extracts from commercial fermented food products of Kimchi, Gochujang, Doenjang, Ganjang and Makgeolli and their suppressive effects against seed-borne diseases were studied. In addition, the suppressive effects of bacterial strains isolated from the fermented foods were screened in vitro and in vivo. Among fifty food extracts, twenty food-extracts suppressed more than 92% incidence of seedling rots in vitro and seven food extracts increased 58.3-66.8% of healthy seedling in the greenhouse. Among 218 isolates from the fermented foods, 29 isolates showing high antifungal activity against seven seed-borne fungal pathogens were selected. Among 29 isolates, 13 isolates significantly reduced seedling rot and increased healthy seedlings. Sixteen isolates with high antifungal activity and suppressive effect against sesame seedling rots were identified by 16S rRNA sequencing. Fourteen of sixteen isolates were identified as Bacillus spp. and the other two isolates from Makgeolli were identified as Saccharomyces cerevisiae. It was confirmed that B. amyloliquifaciens was majority in the effective bacterial population of Korean fermented foods. In addition, when the bioformulations of the two selected effective microorganisms, B. amyloliquifacien Gcj2-1 and B. amyloliquifacien Gcj3-1, were prepared in powder forms using bentonite, kaolin, talc and zeolite, talc- and kaolin-bioformulation showed high control efficacy against sesame seed-borne disease, followed by zeolite-bioformulation. Meanwhile control efficacy of each bentonite-bioformulation of B. amyloliquifacien Gcj2-1 and B. amyloliquifacien Gcj3-1 was lower than that of bacterial suspension of them. It was found that the selected effective microorganisms from Korean fermented foods were effective for controlling seed-borne diseases of sesame in vitro and in the greenhouse. We think that Korean fermented food extracts and useful microorganisms isolated from the extract can be used as bio-control agents for suppressing sesame seed-borne diseases based on above described results.

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

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.41 no.11
• /
• pp.1626-1631
• /
• 2012

Sixty strains of lactic acid bacteria were isolated from kimchi and used as a starter for fermented tofu. Among the isolated strains, strain KL-6 showed antimicrobial activity against various pathogens, antioxidative activity, and viability in artificial gastric juice and artificial bile acid. The selected strain KL-6 was identified as Pediococcus acidilactici KL-6 by morphological and physiological tests, including Gram staining, catalase test, and 16S rRNA sequencing. The fermentation characteristics of tofu with a kimchi ingredient mixture (Control) consisting of red pepper, garlic, ginger, sugar, salt, jeotgal, and juice of chinese cabbage were compared with those of tofus inoculated with strain KL-6 and the kimchi ingredient mixture (TL) or a pre-fermented kimchi ingredient mixture (TPL) for 24 hr at $37^{\circ}C$. The pH levels of all tested tofu samples decreased after 1 week of fermentation, reaching 3.96 (control), 3.97 (TL), and 4.03 log cfu/g (TPL) after fermentation for 14 weeks at $20^{\circ}C$. Total aerobe content of fermented tofu increased until 2 weeks of fermentation, but decreased steadily thereafter. The number of lactic acid bacteria reached $10^6$ cfu/g after 1 week of fermentation in TL and TPL, whereas it took 2 weeks for the control. The number of lactic acid bacteria in all tested tofu samples reached $10^3$ cfu/g after 14 weeks of fermentation at $20^{\circ}C$. Coliform bacteria were not detected in TL or TPL after 1 week of fermentation. The sensory scores of TL and TPL were higher than that of control in terms of taste, flavor, texture, and overall acceptability. The sensory quality of TPL was the best among all tested fermented tofu samples.

• Food Science and Preservation
• /
• v.24 no.5
• /
• pp.707-713
• /
• 2017

The objective of this study was to select yogurt starter from Korean traditional fermented foods. The 2 strains (KM24, KM32) among 50 strains of isolated lactic acid bacteria selected as starter based on milk clotting ability, antimicrobial activity against various pathogens, tolerance in artificial gastric and bile juice and growth in 10 % skimmed milk. The strains were identified as Lacobacillus plantarum (KM32) and Pediococcus pentosacesus (KM24) by 16S rRNA gene sequencing. Viable cell number of yogurt fermented with mixed strains (KM24 and KM32) was 9.66 log CFU/mL after fermentation for 48 h and maintained $10^9CFU/mL$ during fermentation for 72 h at $37^{\circ}C$. The pH and titratable acidity of mixed cultured yogurt were 4.25% and 0.83% after fermentation for 48 h at $37^{\circ}C$, respectively. The physico-chemical characteristics of mixed cultured yogurt after fermentation for 48 h were $38.45{\mu}g/mL$ (polyphenol content), 48.57% (DPPH radical scavenging activity) and 465.40 cp (viscosity), respectively. The mixed cultured yogurt maintained $10^9CFU/mL$ of lactic acid bacteria during storage 10 days at $4^{\circ}C$. The viable cell number of yogurt prepared with mixed culture(KM32+KM24) maintained higher and than that of control (L. casei) during storage. These results indicated the potential use of selected strains (KM32+KM24) isolated from kimchi as a yogurt starter with strong acid tolerance and probiotics properties.