• International Journal of Industrial Entomology and Biomaterials
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• v.44 no.2
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• pp.37-43
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• 2022

Silkworm food has been found to be effective for dementia, liver function, lowering blood sugar, and possesses antioxidant properties, which has been attracting attention as a health functional food. In this study, methods for enhancing the functionality of silkworms were explored and the production potential of high-functional silkworms was analyzed. For enhancing antioxidant activity, ascorbic acid, caffeic acid, laminarin, and glutathione were injected or fed to 5th instar silkworms, and the antioxidant activity of silkworm extract was comparatively analyzed. There was no significant change in polyphenol and flavonoid content, but it was confirmed that 2,2-diphenyl-1-picrylhydrazyl radical scavenging ability, superoxide dismutase-like activity, and reducing power were slightly increased after injection of ascorbic acid, caffeic acid, and glutathione. To confirm the increase in antioxidant efficacy through feeding, an inducer was mixed with sucrose and sprayed on mulberry leaves. As a result, the growth rate of silkworms improved and all indicators of antioxidant activity were improved in silkworms fed with ascorbic acid and glutathione. Considering these results, producing high-functional silkworms was deemed possible.

• Korean Journal of Microbiology
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• v.54 no.4
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• pp.398-409
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• 2018

In the present study, biogenic amine-forming Bacillus spp. and bacteriocin-producing lactic acid bacteria (LAB) isolated from Doenjang were generally identified through 16S rRNA gene sequencing, and the physicochemical and microbiological characteristics of cheonggukjang prepared using the isolated strains were investigated. Biogenic amine-producing bacteria from the samples were identified as Bacillus licheniformis DB102, B. subtilis DB203, B. stearothermophilus DB206, B. pumilus DB209, B. subtilis DB310, B. coagulans DB311, B. cereus DB313, B. amyloliquefaciens DB714, B. amylolique-faciens DB915, B. licheniformis DB917, B. cereus DB1019, B. subtilis DB1020, B. megaterium DB1022. The bacteriocin-producing LAB showed antibacterial effect against biogenic amine-producing Bacillus spp. were identified as Lactobacillus plantarum DLA205, L. brevis DLA501, L. fermentum DLA509, L. acidophilus DLA703, and Enterococcus faecalis DLA804. The bacteriocin produced by the LAB significantly decreased the viable numbers and the amine production ability of the biogenic amine-forming Bacillus spp. in a concentration dependent manner. Therefore, the pH, ammonia nitrogen and biogenic amine content of cheonggukjang prepared by mixed culture of the LAB and Bacillus spp. were significantly decreased compared to the control group.

• Korean Journal of Microbiology
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• v.52 no.3
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• pp.254-259
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• 2016

Acinetobacter sp. B-W producing siderophore, 2, 3-dihydroxybenzoic acid (DHB) was analyzed for plasmid content. Strain B-W harbored plasmid of 20 kb in size. Growth at $43^{\circ}C$ was effective in producing mutant cured of plasmid of strain B-W. This mutant lost the ability to produce 2, 3-DHB. Formation of siderophore halos on the chrome azurol S (CAS) agar medium was not detected by cured strain B-W. pHs of supernatants of wild type strain B-W and cured mutant grown in glucose and $MnSO_4$ containing medium at $28^{\circ}C$ for 3 days were 4.5 and 8.5, respectively. Antibiotic resistance against ampicillin, actinomycin D, bacitracin, lincomycin, and vancomycin was lost in cured mutant. Plasmid curing of strain B-W resulted in drastic reduction of minimal inhibitory concentration (MIC) of several antibiotics. E. coli $DH5{\alpha}$ was transformed with plasmid isolated from strain B-W. The transformant E. coli $DH5{\alpha}$ harbored a plasmid of the same molecular size as that of the donor plasmid. Transformant E. coli $DH5{\alpha}$ produced 2, 3-DHB and contained antibiotic resistant ability. Thus a single plasmid of 20 kb seemed to be involved in 2, 3-DHB production. Genes encoding resistance to antibiotics were also supposed to be located on this plasmid.

• Microbiology and Biotechnology Letters
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• v.8 no.2
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• pp.87-92
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• 1980

These experiments were conducted to manage more safe the selected strains and improve their characteristics. The results obtained were as follows: Preservation on soil at the range of 0 to 5 C was suitable and there were no remarkable changes on their abilities to produce citric acid until 10 months preservation. The successive transfer of spore slightly stimulated the selected strain, M-315 to produce citric acid and the spore precultured on sporulation medium for 7-10 days was desirable as inoculum. Under UV-irradiation from the selected strains, 109 mutants whose morphological characteristics were changed were isolated. Among them, the mutant M-80-12 was shown 3.2％ increase on acid producing ability than that of its parent.

• Food Science of Animal Resources
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• v.33 no.5
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• pp.595-602
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• 2013

As a major inhibitory neurotransmitter of the central nervous system in animals, ${\gamma}$-aminobutyric acid (GABA) has several physiological functions, such as anti-hypertensive, diuretic, tranquilizer and anti-stress effects in human. In order to determine strains with high GABA producing ability and glutamate decarboxylase (GAD) activity, 273 bacteria were isolated from various types of Kimchi. Strain K255 contained $386.37{\mu}g/mL$ of GABA in MRS broth containing 1% MSG, $600.63{\mu}g/mL$ of GABA in MRS broth containing 2% MSG and $821.24{\mu}g/mL$ of GABA in MRS broth containing 3% MSG. It showed that K255 had the highest GABA production ability compared to other commercial lactic acid bacteria. K255 was identified as Lactobacillus plantarum based on its API carbohydrate fermentation pattern and 16S rDNA sequence. K255 was investigated for its physiological characteristics. The optimum growth temperature of K255 was $37^{\circ}C$and cultures took 13 h to reach the pH 4.4. K255 showed more sensitive to bacitracin in a comparison of fifteen different antibiotics, and showed most resistance to kanamycin and vancomycin. Moreover, it was comparatively tolerant to bile juice and acid and displayed resistance to Escherichia coli, Salmonella Typhimurium, Staphylococcus aureus, with rates of 30.8%, 29.7%, and 23.4% respectively. These results demonstrate that K255 could be an excellent strain for the production of functional products.

• Environmental Analysis Health and Toxicology
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• v.14 no.3
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• pp.87-93
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• 1999

Antioxidative and scavenging effects were investigated by using two hyaroxycinnamic acids (caffeetannins). such as caffeic acid and chlorogenic acid, on oxidative stress and hepatotoxicity that induced by paraquat. The results are summerized as follows: 1. To assess radical scavenging ability, reduction concentration (IC$\sub$50/) of 1.1 diphenyl-2-dipicrylhydrazine (DPPH) were measured. IC$\sub$50/ values of caffeic acid and chlorogenic acid were 29.7 ${\pm}$0.6 ${\mu}$M and 26.0${\pm}$0.5 ${\mu}$M respectively. Their radical scavenging activities showed concentration-dependent manner. 2. In H$_2$O$_2$-induced hemolysis assay to rat blood, caffeic acid and chlorogenic acid led to different effects, whose hemolysis inhibition ratios at 100 ${\mu}$M were 45.2${\pm}$7.1% and 11.6${\pm}$3.1% respectively 3. In hypoxanthine-xanthine oxidase system producing superoxide anion, caffeic acid and chlorogenic acid showed different inhibitory activities of xanthine oxidase showing 36.8${\pm}$4.3% and 5.4${\pm}$2.3% respectively. 4. To microsomal NADPH dependent cytochrome p-450 reductase in rat liver, paraquat consumed NADPH at a dose-dependent manner from 0 to 1 ${\mu}$M paraquat concentration. Caffeic acid and chlorogenic acid blocked NADPH consumption rates at concentration-dependent manner and inhibition ratios at 100 ${\mu}$M were 67.6% and 59.2% respectively. 5. Administration (30mg/kg, iv) of paraquat to rats caused the marked elevation of glutamic oxaloacetic transaminase (GOT), glutamic pyruvic transaminase (GPT), lactate dehydrogenase (LDH), alkaline phosphatase (ALP) and lipid peroxides (LPO) in the serum and lipid peroxides in the microsome as compared to the control group. Serum GOT, GPT, LDH, ALP and LPO and liver microsomal LPO were reduced significantly by caffeic acid (50mg/kg), chlorogenic acid (25mg/kg) and silymarin (150 mg/kg) as compared to the paraquat group. From these results, caffeic acid and chlorogenic acid exerted their antioxidative agents by removing reactive oxygen substance (ROS) and scavenging effects by inhibiting ROS generating enzyme. As a general, two hydroxyeinnamic acids showed the useful compounds for scavenger and reducer on the paraquat induced hepatotoxicity.

• Archives of Pharmacal Research
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• v.26 no.12
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• pp.1087-1095
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• 2003

Betulinic acid (BA), a pentacyclic triterpene isolated from Lycopus lucidus, has been reported to be a selective inducer of apoptosis in various human cancer and shown anti-inflammatory and immunomodulatory properties. We postulated that BA modulates the immunomodulatory properties at least two groups of protein mediators of inflammation, interlukin-1$\beta$ (IL-1$\beta$) and the tumor necrosis factor- $\alpha$ (TNF-$\alpha$) on the basis of the critical role of the monocytes and tissue macrophages in inflammatory and immune responses. TNF-$\alpha$ and IL-1$\beta$ were produced by BA in a dose dependent manner at concentration of 0.625 and 10 $\mu$g/mL. The production of NO associated with iNOS was inhibited when treated with LPS at the concentration of 2.5 to 20 $\mu$g/mL of BA whereas COX-2 expression was decreased at 2.5 to 20 $\mu$g/mL. These modulations of inflammatory mediators were examined in LPS-stimulated RAW 264.7 cells and peritoneal macrophages. The morphology of macrophage was also examined and enhanced surface CD 40 molecule was expressed when treated BA at 0.625∼5 $\mu$g/mL with or without LPS. Furthermore, BA (20 $\mu$g/mL) enhanced apoptosis by producing DNA ladder in the RAW 264.7 cells. Our results indicated that BA induced activation of macrophage and pro-inflammatory cytokines. This may provide a molecular basis for the ability of BA to mediate macrophage, suppress inflammation, and modulate the immune response.

• Korean Journal of Food Science and Technology
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• v.35 no.6
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• pp.1244-1247
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• 2003

The purpose of this study was to isolate lactic acid bacteria that produced L(+) lactic acid from infant feces. Thirteen colonies were isolated with a MRS-plate containing 0.5% $CaCO_3$ to determine their ability to produce lactic acid. Based on their lactic acid production, 10 strains of Lactobacillus were identified to assess the ratio of lactate isomer using HPLC. A strain producing L-lactic acid was identified as Lactobacillus acidophilus, using API carbohydrate fermentation patterns and physiological tests, and named KY1909. The strain exhibited good acid tolerance in an artificial gastric juice as well as high bile resistance in MRS containing 0.5% bile acids. L. acidophilus KY1909 produced D(-) and L(+) lactic acid at a ratio of 6 : 94; whereas commercial strains of Lactobacillus acidophilus produced D(-) and L(+) lactic acid at a ratio of 1 : 1. These results demonstrate the L. acidophilus KY1909 can be utilized in fermented milk products and dietary supplements as a probiotic culture.

• Journal of Ginseng Research
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• v.45 no.2
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• pp.218-227
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• 2021

Background: Panax ginseng is one of the most important medicinal plants and is usually harvested after 5 to 6 years of cultivation in Korea. Heavy metal (HM) exposure is a type of abiotic stress that can induce oxidative stress and decrease the quality of the ginseng crop. Siderophore-producing rhizobacteria (SPR) may be capable of bioremediating HM contamination. Methods: Several isolates from ginseng rhizosphere were evaluated by in vitro screening of their plant growth-promoting traits and HM resistance. Subsequently, in planta (pot tests) and in vitro (medium tests) were designed to investigate the SPR ability to reduce oxidative stress and enhance HM resistance in P. ginseng inoculated with the SPR candidate. Results: In vitro tests revealed that the siderophore-producing Mesorhizobium panacihumi DCY119^T had higher HM resistance than the other tested isolates and was selected as the SPR candidate. In the planta experiments, 2-year-old ginseng seedlings exposed to 25 mL (500 mM) Fe solution had lower biomass and higher reactive oxygen species level than control seedlings. In contrast, seedlings treated with 10⁸ CFU/mL DCY119^T for 10 minutes had higher biomass and higher levels of antioxidant genes and nonenzymatic antioxidant chemicals than untreated seedlings. When Fe concentration in the medium was increased, DCY119^T can produce siderophores and scavenge reactive oxygen species to reduce Fe toxicity in addition to providing indole-3-acetic acid to promote seedling growth, thereby conferring inoculated ginseng with HM resistance. Conclusions: It was confirmed that SPR DCY119^T can potentially be used for bioremediation of HM contamination.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.6
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• pp.987-994
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• 2000

Aspergillus coreanus NR 15-1, Asp. oryzae NR 15-3 and Asp. oryzae NR 2-5 isolated from traditional Korean nuruk were screened as parental strains producing starch hydrolyzing enzymes. They were mutagenized by N-methyl -N'-nitro-N-nitrosoguanidine (NTG) and mutants were isolated for analysis of various amylase activities and the ability of acid production. Among them, the mutants harboring high saccharogenic activity, dextrinogenic activity, and the ability of acid production were selected. Fifteen, six, and five strains of mutants were isolated from Asp. coreanus NR 15-1, Asp. oryzae NR 2-5, and Asp. oryzae NR 15-3, respectively followed by NTG mutagenesis. Among these mutants, thirteen strains were identified as auxotrophic mutants. \ulcorner (Arg.￣) mutant from Asp. coreanus NR 15-1 showed high glucoamylase activity and total acid productivity. Z6 (Ade.￣) mutant from Asp. oryzae NR 2-5 showed the highest $\alpha$-amylase activity, therefore \ulcorner and Z6 mutant were selected.