• Journal of Microbiology and Biotechnology
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• v.25 no.12
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• pp.2043-2048
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• 2015

Bacillus thuringiensis microbial insecticide products have been applied worldwide. Although a few cases of B. thuringiensis foodborne illness have been reported, little is known about the toxigenic properties of B. thuringiensis isolates. The aims of this study were to estimate the pathogenic potential of B. thuringiensis selected from microbial insecticide products, based on its possession of toxin genes and production of enterotoxins. Fifty-two B. thuringiensis strains selected from four kinds of microbial insecticide products were analyzed. PCR assay for detection of toxin genes and immunoassay for detection of enterotoxins were performed. The hemolysin BL complex as a major enterotoxin was produced by 17 (32.7%), whereas the non-hemolytic enterotoxin complex was detected in 1 (1.9%) of 52 B. thuringiensis strains. However, cytK, entFM, and ces genes were not detected in any of the tested B. thuringiensis strains. The potential risk of food poisoning by B. thuringiensis along with concerns over B. thuringiensis microbial insecticide products has gained attention recently. Thus, microbial insecticide products based on B. thuringiensis should be carefully controlled.

• Journal of Microbiology and Biotechnology
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• v.25 no.7
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• pp.1070-1083
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• 2015

A gene (GT-SM3B) encoding a thermostable secreted oligoendopeptidase (GT-SM3B) was cloned from the thermophile Geobacillus thermoleovorans DSM 15325. GT-SM3B is 1,857 bp in length and encodes a single-domain protein of 618 amino acids with a 23-residue signal peptide having a calculated mass of 67.7 kDa after signal cleavage. The deduced amino acid sequence of GT-SM3B contains a conservative zinc metallopeptidase motif (His⁴⁰⁰-Glu⁴⁰¹-X-XHis⁴⁰⁴). The described oligopeptidase belongs to the M3B subfamily of metallopeptidases and displays the highest amino acid sequence identity (40.3%) to the oligopeptidase PepF_Ba from mesophilic Bacillus amyloliquefaciens 23-7A among the characterized oligopeptidases. Secretory production of GT-SM3B was used, exploiting successful oligopeptidase signal peptide recognition by Escherichia coli BL21 (DE3). The recombinant enzyme was purified from the culture fluid. Homodimerization of GT-SM3B was determined by SDS-PAGE. Both the homodimer and monomer were catalytically active within a pH range of 5.0–8.0, at pH 7.3 and 40℃, showing the K_m, V_max, and k_cat values for carbobenzoxy-Gly-Pro-Gly-Gly-Pro-Ala-OH peptidolysis to be 2.17 ± 0.04 × 10^-6 M, 2.65 ± 0.03 × 10^-3 µM/min, and 5.99 ± 0.07 s^-1, respectively. Peptidase remained stable at a broad pH range of 5.0–8.0. GT-SM3B was thermoactive, demonstrating 84% and 64% of maximum activity at 50℃ and 60℃, respectively. The recombinant oligopeptidase is one of the most thermostable M3B peptidase, retaining 71% residual activity after incubation at 60℃ for 1 h. GT-SM3B was shown to hydrolyze a collagenous peptide mixture derived from various types of collagen, but less preferentially than synthetic hexapeptide. This study is the first report on an extracellular thermostable metallo-oligopeptidase.

• Journal of Microbiology and Biotechnology
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• v.25 no.7
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• pp.1093-1100
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• 2015

Acetate and lactate in growth media are detrimental to the production of Thermus maltogenic amylase (ThMA), a heterologous protein, as well as to the growth of recombinant Escherichia coli. Only 50 mM of acetate or 10 mM of lactate reduced 90% of specific ThMA activity. In this study, mutant E. coli strains blocked in the ackA-pta or ackA-pta and ldh pathways were created, characterized, and assessed for their culture performace in 300 L-scale fermentation. The ackApta and ldh double-mutant strain formed significantly less lactate and acetate, and produced a concomitant increase in the excretion of pyruvate (17.8 mM) under anaerobic conditions. The ackA-pta mutant strain accumulated significant acetate but had an approximately 2-fold increase in the formation of lactate. The ackA-pta and ldh double-mutant strain had superior overall performance in large-scale culture under suboptimal conditions, giving 67% higher cell density and 66% higher ThMA activity compared with those of the control strain. The doublemutant strain also achieved a 179% improvement in volumetric ThMA production.

• Nutrition Research and Practice
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• v.7 no.5
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• pp.352-358
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• 2013

Korean pine nut oil (PNO) has been reported to have favorable effects on lipid metabolism and appetite control. We investigated whether PNO consumption could influence weight gain, and whether the PNO-induced effect would result in an improvement of immune function in high-fat diet (HFD)-induced obese mice. C57BL/6 mice were fed control diets with 10% energy fat from either PNO or soybean oil (SBO), or HFDs with 45% energy fat from 10% PNO or SBO and 35% lard, 20% PNO or SBO and 25% lard, or 30% PNO or SBO and 15% lard for 12 weeks. The proliferative responses of splenocytes upon stimulation with concanavalin A (Con A) or lipopolysaccharide (LPS), Con A-stimulated production of interleukin (IL)-2 and interferon (IFN)-${\gamma}$, and LPS-stimulated production of IL-6, IL-$1{\beta}$, and prostaglandin $E_2$ ($PGE_2$) by splenocytes were determined. Consumption of HFDs containing PNO resulted in significantly less weight gain (17% less, P < 0.001), and lower weight gain was mainly due to less white adipose tissue (18% less, P = 0.001). The reduction in weight gain did not result in the overall enhancement in splenocyte proliferation. Overall, PNO consumption resulted in a higher production of IL-$1{\beta}$ (P = 0.04). Replacement of SBO with PNO had no effect on the production of IL-2, IFN-${\gamma}$, IL-6, or $PGE_2$ in mice fed with either the control diets or HFDs. In conclusion, consumption of PNO reduced weight gain in mice fed with HFD, but this effect did not result in the overall improvement in immune responses.

• Nutritional Sciences
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• v.7 no.1
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• pp.8-16
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• 2004

The purpose of this study was to investigate the gene profiles that were up- or down-regulated in the livers of high-fat diet-induced obese mice and $db_-/db_-$ mice with deficient leptin receptor. C57/BL6 normal mice and $db_-/db_-$ mice, respectively, were divided into two groups and fed a standard or high-fat diet for four weeks. Liver weight was unchanged in the normal mice but the high-fat diet led to a 10% weight increase in the $db_-/db_-$mice. Adipose tissue mass increased by about 88% in the normal mice that were fed a high-fat diet and by about 17% in the $db_-/db_-$mice on the high-fat diet. In terms of serum lipids, total cholesterol significantly increased in mice on the high-fat diet. Microarray analysis was carried out using total RNA isolated from the livers of standard or high-fat diet-fed mice of the normal and $db_-/db_-$ strains. The change of gene expression was confirmed by RT-PCR. About 1.6% and 6.8% of total genes, respectively, showed different expression patterns in the normal mice fed the high-fat diet and $db_-/db_-$ mice. As a result of microarray, many genes involved in metabolism and signal pathways were shown to have different expression patterns. Expression of Mgst3 gene increased in the livers of normal and $db_-/db_-$ mice that were fed a high-fat diet. Wnt7b and Ptk9l were down-regulated in the livers of the normal mice and $db_-/db_-$ mice that were fed a high-fat diet. In conclusion, a high-fat diet induced obesity and affected gene expression involved in metabolism and signal pathway.

• Journal of Microbiology and Biotechnology
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• v.17 no.11
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• pp.1868-1874
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• 2007

We have developed a robotic system for an automated parallel cell cultivation process that enables screening of induction parameters for the soluble expression of recombinant protein. The system is designed for parallelized and simultaneous cultivation of up to 24 different types of cells or a single type of cell at 24 different conditions. Twenty-four culture vessels of about 200 ml are arranged in four columns${\times}$six rows. The system is equipped with four independent thermostated waterbaths, each of which accommodates six culture vessels. A two-channel liquid handler is attached in order to distribute medium from the reservoir to the culture vessels, to transfer seed or other reagents, and to take an aliquot from the growing cells. Cells in each vessel are agitated and aerated by sparging filtered air. We tested the system by growing Escherichia coli BL21(DE3) cells harboring a plasmid for a model protein, and used it in optimizing protein expression conditions by varying the induction temperature and the inducer concentration. The results revealed the usefulness of our custom-made cell cultivation robot in screening optimal conditions for the expression of soluble proteins.

• The Journal of Korean Medicine
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• v.32 no.3
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• pp.10-17
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• 2011

Objective: To evaluate the immune-stimulatory potential of extracts of Broussonetia kazinoki Siebold (BK) on specific cellular and humoral immune responses in ovalbumin (OVA)-immunized mice. Material and Methods: C57BL/6 mice were immunized intraperitoneally with OVA/alum ($100{\mu}g/200{\mu}g$) on days 1, 8, and 15. BK (100, 300 or 1000 mg/kg) was given to mice orally for 21 days (from day 1 to day 21). At day 22, OVA-, lipopolysaccharide (LPS)- and concanavalin A (Con A)-stimulated splenocyte proliferation and OVA-specific and total antibodies were measured in plasma. Further, the effects of BK on expression of cytokine mRNA in OVA-immunized mice splenocytes were evaluated by RT-PCR analysis. Results: BK significantly enhanced OVA-, LPS-, and Con A-induced splenocyte proliferation in OVA-immunized mice (p<0.01). BK also significantly enhanced total IgM and OVA-specific IgG1 levels in plasma compared with the OVA control group. Moreover, BK up-regulated significantly the expression of mRNA level of IL-2 and IFN-${\gamma}$ in splenocytes. Conclusions: BK has immune-stimulating activity in an OVA-immunized mouse model system, enhancing the Th1 immune response. BK showed no cytotoxicity in this system, suggesting that BK may be a safe and effective adjuvant in humans.

• Journal of Physiology & Pathology in Korean Medicine
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• v.17 no.3
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• pp.711-718
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• 2003

Wanpae-tang is suggested to have antitumor activity on lung cancer. This study was performed to investigate antitumor, immune response, and apoptotic effects by Wanpae-tang in the cancer cell lines and C57BL/6 mice. Experimental studies were progressed through the anticancer activities such as, survival time, cell cytotoxicity, natural killer cell activity, productivity of interleukins and apoptotio effects. The results were summarized as follows: 1. Median survival time of Wanpae-tang treated group was prolonged to 4.1%, as compared with control group, but was not significant. 2. On the MTT assay, half-maximal inhibitory concentration(IC50) of Wanpae-tang was 15.00 ㎎/㎖ in HeLa cell, and 4.158 ㎎/㎖ in HRT-18 cell. 3. Natural killer cell activity in Wanpae-tang treated group was decreased in case of 100:1 and 10:1 effect cell/target cell ratio. 4. Production of interleukin-2, 4, 12 in Wanpae-tang treated group were significantly increased. 5. On the studies of Wanpae-tang induced apoptosis, a DNA fragmentation patterns were not appeared.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.17 no.1
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• pp.82-93
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• 2004

Recently many efforts were focused to understanding the mechanical insights of melanogenesis to develop the agents for hyper-pigmentation and hypo-pigmentation. In the melanin biosynthetic pathway, tyrosinase is the rate limiting enzyme, and ${\alpha}$-melanocyte stimulating hormone(MSH) or cAMP-elevating agents stimulate melanogenesis and enhance the melanin synthesis and the tyrosinase activity. The author has analyzed the effects of Radix Trichosanthis on the basal Melanogenic activities of Bl6/F10 mouse melanoma cells, and on the ${\alpha}$-MSH or forskolin-induced melanogenesis. Radix Trichosanthis alone markedly suppressed melanin content and tyrosinase activity in a dose-dependent manner. Pretreatment of the cells with Radix Trichosanthis also suppressed the increase of ${\alpha}$-MSH(10 nM) or forskolin(20 ${\mu}$M)-induced melanin content and tyrosinase activity. The decrease in the tyrosinase activity was paralled by a decrease in the abundance of tyrosinase protein and tyrosinase promoter activity. Pretreatment of the cells with Radix Trichosanthis also inhibited the increase of forskolin(20 ${\mu}$M) induced the amount of tyrosinase protein and tyrosinase promoter activity. The results of DOPA staining revealed that pretreatment of the cells with Radix Trichosanthis showed less intensity than B16 melanoma cells stimulated with ${\alpha}$-MSH or forskolin. These results suggest that Radix Trichosanthis inhibits melanogenesis and abrogates ${\alpha}$-MSH and cAMP-induced melanogenesis in B16 melanoma cells.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.5
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• pp.693-699
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• 2004

Live animal selection programs that favor animals with a minimum amount of carcass fat are used for improving breeding flocks of sheep. To predict carcass characteristics of live sheep using body measurements in breeding flocks, 200 male and female lambs of two fat-tailed Iranian sheep breeds (Moghani and Makui) were used. Depth of soft tissue over the 12th rib of the live animals was measured with ultrasound (ULGR) and with hypodermic needle (NGR). The height at withers (HW), body length (BL), circumference of heart girth (CH) and width of hooks (WH), were measured. All animals were slaughtered; carcasses were cut into joints and dissected. Breed had a significant effect on all of the live easurements. The Moghani breed showed a higher value for HW, CH, ULGR and NGR, compared to that of Makui. Except for soft tissue depths; ULGR, NGR and GR, the male lambs showed higher values in live and carcass measurements than females. Percentages of carcass, total fat and intermuscular fat in females were higher than that of male lambs. In spite of the higher amount of subcutaneous and intermuscular fat in female (which is usually used for their physiological need, such as pregnancy and lactation), the male lambs had a heavier fat-tail than females. There was a wide range of variation of percentage of total carcass fat and total chemical fat content of carcass in the two breeds. Eventually this wide variation could be use by animal breeders for selection of animals with a lesser amount of carcass fat. Live weight of lambs showed a relatively low correlation with percentage of carcass lean, total fat and subcutaneous and intermuscular fat. Total lean meat was predicted with relatively high coefficients of determination in the two breeds ($R^2$=0.61 and 0.89, respectively). Live weight and carcass traits were predicted using simple measurements, but with $R^2$ ranging from 0.53 to 0.93.