• Korean Journal of Food Science and Technology
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• v.41 no.4
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• pp.399-404
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• 2009

The goal of this study was to improve the quality of cheonggukjang by the optimization of the inoculation methods of the Bacillus subtilis (B. subtilis) and Lactobacillus plantarum (L. plantarum) strains. In order to optimize the mixed cultivation of B. subtilis and L. plantarum, the B. subtilis strain was inoculated into steamed soybeans after cultivation of L. plantarum. Inoculation size of B. subtilis was changed to the simultaneous inoculation method in order to stimulate the growth of the L. plantarum in cheonggukjang. The viable cell count of L. plantarum increased from $2{\times}10^7$ CFU/g to $2-6{\times}10^8$ CFU/g and B. subtilis grew to $9{\times}10^8$ CFU/g. These results showed that 2 strains were successfully able to grow in the steamed soybean for good quality of cheonggukjang by optimization of the inoculation methods. The sensory evaluation indicated that a favorable aroma and overall acceptance of cheonggukjang by the optimized mixed cultivation of B. subtilis and L. plantarum, which was relatively higher than those of cheonggukjang by single strain inoculation of B. subtilis.

• Journal of Life Science
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• v.21 no.12
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• pp.1689-1697
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• 2011

In this study, we investigated the anti-inflammation effect of Persicaria thunbergii (P. thunbergii) on RAW 264.7 murine macrophage cells. The anti-inflammatory activity of P. thunbergii was determined by measuring expression of the LPS-induced inflammatory proteins, inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2) and nuclear factor-${\kappa}B$ (NF-${\kappa}B$), and the production of nitric oxide (NO) and prostaglandin $E_2$ ($PGE_2$). Methanol extract of P. thunbergii decreased the expression of iNOS, COX-2 and NF-${\kappa}B$, and increased the expression of HO-1 in LPS-stimulated RAW264.7 cells. Methanol extract was fractioned by n-butanol, hexane and ethyl acetate (EtOAc) and each fraction was tested for inhibitory effects on inflammation. Among the sequential solvent fractions, the EtOAc soluble fraction was investigated by the expression of prostaglandin $E_2$ ($PGE_2$), and showed decreasing form to the dose-dependent manner. EtOAc extract showed the most effective inhibitory activity of the expression of iNOS, COX-2 and NF-${\kappa}B$, and the production of NO. The study showed that P. thunbergii has anti-inflammatory activity through the decrease of NO and inhibition of iNOS, COX-2, $PGE_2$ and NF-${\kappa}B$ expression, and by the increase of HO-1 enzyme. This study needs for more investigation to find out the most effective single compound with anti-inflammatory activity.

• Korean Journal of Materials Research
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• v.3 no.2
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• pp.175-184
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• 1993

Abstract Co-and/or AI-added Nd-Fe-B-based magnetic alloys were fabricated by using vacuum induction melting frunace, and melt-spun ribbons were made of the magnetic alloys with single roll rapid quenching method. The variation of magnetic properties of the melt-spun ribbons as a function of Cuwheel velocity (Vs) were investigated. Bonded magnets were made of the optimally quenched ribbon fragments, and the magnetic properties of the melt-spun ribbons and the bonded magnets were studied, relating to the microstructure and crystalline structure. Cu-wheel surface velocity had a strong effect on the magnetic properties of the melt-spun ribbons, and the maximum properties were obtained around Vs =20m/sec. The optimally quenched ribbon had a cellura-type microstructure, in which fine N$d_2$F$e_14$B grains were surrounded by thin Nd-rich phase. In case of a 2.1at% AI-added melt-spun ribbon, the magnetic properties were as follows: iHc, Br, and (BH)max were 15.5KOe, 7.8KG and 8.5MGOe respectively. And resin bonded magnets were fabricated by mixing optimally quenched ribbon fragments with 2.5wt % polyamide resin, compacting and binding at room temperature. The iHc, Br and (BH)max of bonded magnet were lO.2KOe, 4.4KG and 3.3MGOe respectively. And hot-pressed magnets were made by pressing the overquenched ribbons at high temperature. The magnetic properties of hot-pressed magnets were better than those of bonded magnets, and when the holding time was 8 minutes, the iHc, Br, and (BH)max of the hot-pressed magnet were 1O.8KOe, 7.3KG and 8.0MGOe respectively. Domain structure was mainly maze pattern, which means that the easy magnetization axis could be aligned, and the domain width of the hot-pressed magnets was smaller than that of bonded magnets.

• Korean Journal of Materials Research
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• v.5 no.6
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• pp.748-753
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• 1995

Solid solution of NaNb $O_3$70 mol% and SrTi $O_3$30 mol% was single phase. A broad dielectric peak was found at about l00K. Crystal structure was analysed at room temperature and 12K using Rietveld analysis. The unit cell was assigned to have a a doubled lattice parameter of simple perovskite sturcture at room temperatue, the structure was orthorombic with space group Pmmn. At 12K, the structure was also orthorombic with space group Pnma. This structure change with temperature was due to the distortion of oxygen octahedron. This distortion of oxygen octahedron was made by the decrease of (Ti, Nb)-O bounds length with no variation of (Ti, Nb)-O-(Ti, Nb) bound angle. Therefore the broad dielectirc peak about l00K was attributed to the structural change casued by oxygen octahedron distortion.

• Korean Journal of Microbiology
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• v.45 no.4
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• pp.419-424
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• 2009

To provide the basis of biosensor based on the lux genes from bioluminescent bacteria of Photobacterium leiognathi and Vibrio harveyi, we test the expression of lux genes in several strains of Escherichia coli. The expression of the recombinant plasmid of PlXba.pT7-3, containing all lux genes requiring for light emission without adding substrate, in E. coli 43R was so strong to see the blue-green light in single colony as well as in the alginate immobilized cell. In addition, the light intensity was decreased by adding heavy metal ion such as cadmium and zinc ions. These result raise the possibility that a biosensor can be developed using the lux genes system.

• KSBB Journal
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• v.19 no.6 s.89
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• pp.446-450
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• 2004

We investigated the effective culture conditions of anaerobic bacteria, Enterobacter cloacae YJ-1 on hydrogen production. It was cultured with 60 mL of working volume at $35^{\circ}C$, 120 rpm for 40 h. With culture time, hydrogen production and cell growth increased, but residual glucose and pH decreased. When the $2\%$ of glucose was used as single carbon source, hydrogen production was 975.1 mL/L. To enhance hydrogen productivity, mixed carbon sources of glucose and sucrose were added. The maximum hydrogen production was earned at the mixing ratio of 25:75, and it was 1319.5 mL/L. When we added 50 mM of phosphate to protect the pH drop in culture broth, hydrogen production increased 1.3 times more than that of initial concentration. The organic nitrogen sources were more effective than inorganic nitrogen for hydrogen production. Among organic nitrogen, yeast extract was the most effective and its hydrogen production was 1691.3 mL/L. Among 9 of mineral sources, Ferric citrate and $NaMoO_4$ were especially effective, and their productions were 1782.3 mL/L and 1784.8 mL/L, respectively.

• KSBB Journal
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• v.21 no.2
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• pp.133-139
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• 2006

In 'solid-phase' PEGylation, the conjugation reaction occurs as the proteins are attached to a solid matrix, and thus it can have distinct advantages over the conventional, solution-phase process. We report a case study: rhIFN-${\alpha}$-2a was first adsorbed to cation exchange resin and then N-terminally PEGylated by aldehyde mPEG of 5, 10, and 20 kD through reductive alkylation. After the PEGylation, salt gradient elution efficiently recovered the mono-PEGylate in a purified form from the unwanted species such as unmodified IFN, unreacted PEG, and others. The mono-PEGylation and its purification were integrated in a single chromatographic step. Depending on the molecular weight of the mPEG aldehyde used, the mono-PEGylation yield ranged 50-64%. We could overcome the major problems of random, or uncontrollable, multi-PEGylation and the post-PEGylation purification difficulties associated with the solution-phase process. N-terminal sequencing and MALDI-TOF MS confirmed that a PEG molecule was conjugated only to the N-terminus. Compared with the unmodified IFN, the mono-PEGylate showed the reduced anti-viral activity as measured by the cell proliferation assay. The bioactivity was reduced more as the higher molecular weight PEG was conjugated. Immunoreactivity, evaluated indirectly by antibody binding activity using a surface plasmon resonance biosensor, also decreased. Nevertheless, trypsin resistance as well as thermal stability was considerably improved.

• KSBB Journal
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• v.21 no.2
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• pp.144-150
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• 2006

The exploitation of metagenome, the access to the natural extant of enormous potential resources, is the way for elucidating the functions of organism in environmental communities, for genomic analyses of uncultured microorganism, and also for the recovery of entirely novel natural products from microbial communities. The major breakthrough in metagenomics is opened by the construction of libraries with total DNAs directly isolated from environmental samples and screening of these libraries by activity and sequence-based approaches. Screening with activity-based approach is presumed as a plausible route for finding new catabolic genes under designed conditions without any prior sequence information. The main limitation of these approaches, however, is the very low positive hits in a single round of screening because transcription, translation and appropriate folding are not always possible in E. coli, a typical surrogate host. Thus, to obtain information about these obstacles, we studied the genetic organization of individual URF's(unidentified open reading frame from metagenome sequenced and deposited in GenBank), especially on the expression factors such as codon usage, promoter region and ribosome binding site(rbs), based on DNA sequence analyses using bioinformatics tools. And then we also investigated the above-mentioned properties for 4100 ORFs(Open Reading Frames) of E. coli K-12 generally used as a host cell for the screening of noble genes from metagenome. Finally, we analyzed the differences between the properties of URFs of metagenome and ORFs of E. coli. Information derived from these comparative metagenomic analyses can provide some specific features or environmental blueprint available to screen a novel biocatalyst efficiently.

• Journal of Life Science
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• v.16 no.1
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• pp.95-100
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• 2006

This study was carried out to investigate the effects of Salicornia herbacea L. (SH) on carbon tetrachloride $(CCl_4)-induced$ hepatotoxicity. Sprague-Dawley rats were intraperitoneally administered the SH at 100 mg/kg per day for two weeks. Then single dose of $CCl_4$ (3.3 ml/kg) was injected into rats. Twelve hours later, they were anesthesized with ether and dissected. $SH-CCl_4-administered$ group showed $65.56\%\;and\;59.04\%$ of inhibitory effects in aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities, compared to $CCl_4-treated$ group (p<0.05). Malonedialdehyde (MDA) levels of $SH-CCl_4-administered$ group in liver homogenate and mitochondria were significantly inhibited by $53.74\%,\;89.86\%$, and respectively, compared to $CCl_4-treated$ group (p<0.05). Superoxide dismutase (SOD) activities of $SH-CCl_4-administered$ group in liver homogenate and mitochondria were significantly inhibited by $42.51\%,\;and\;38.42\%$, respectively, compared to $CCl_4-treated$ group (p<0.05). The histological examinations showed that the liver cell necrosis and centrilobular congestive aggregation induced by $CCl_4$ were clearly eliminated by the administration of SH. These results suggest that SH could have the protective effects against hepatotoxicity.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.3
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• pp.516-520
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• 2002

This study was designed to investigate the hepatoprotective effects of Semisulcospira libertina and garlic on the acute hepatotoxicity induced by carbon tetrachloride (CCl$_4$) of rats. Male Sprague-Dawley rats weighing 200∼220g were pretreated with dehydrated powder of Semisulcospira libertina (2.1 g/kg, po; SL) and dehydrated powder mixture of Semisulcospira libertina and garlic (3g/kg, 7:3 ratio, po; SG) once daily for 3 consecutive days, and then given a single dose of CCl$_4$(1g/kg in 5ml/kg corn oil, po) and liver function was determined 24 hrs later. Liver damage was assessed by quantitating activities of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), sorbitol dehydrogenase (SDH) and alkaline phosphatase (ALP) as well as by histopathological examination. Pretreatments with SL and SG significantly decleased CCl$_4$-elevated ALT (48% and 61% respectively), AST (32% and 47%) and SDH (51% and 76%), but had no effect on ALP. SL and SG had revealed hepatoprotective effects against CCl$_4$-induced histopathological changes such as severe necrosis, inflammatory cell infiltration and congestion in the central gene of hepatic lobule. These findings demonstrate that SL and SG may haute the hepatoprotective effect on CCl$_4$-induced liver damage.