• Journal of Microbiology and Biotechnology
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• v.22 no.3
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• pp.343-351
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• 2012

In this paper, the kinetics of a cloned special glucosidase, named ginsenosidase type III hydrolyzing 3-O-glucoside of multi-protopanaxadiol (PPD)-type ginsenosides, were investigated. The gene (bgpA) encoding this enzyme was cloned from a Terrabacter ginsenosidimutans strain and then expressed in E. coli cells. Ginsenosidase type III was able to hydrolyze 3-O-glucoside of multi-PPD-type ginsenosides. For instance, it was able to hydrolyze the 3-O-${\beta}$-D-(1${\rightarrow}$2)-glucopyranosyl of Rb1 to gypenoside XVII, and then to further hydrolyze the 3-O-${\beta}$-D-glucopyranosyl of gypenoside XVII to gypenoside LXXV. Similarly, the enzyme could hydrolyze the glucopyranosyls linked to the 3-O-position of Rb2, Rc, Rd, Rb3, and Rg3. With a larger enzyme reaction $K_m$ value, there was a slower enzyme reaction speed; and the larger the enzyme reaction $V_{max}$ value, the faster the enzyme reaction speed was. The $K_m$ values from small to large were 3.85 mM for Rc, 4.08 mM for Rb1, 8.85 mM for Rb3, 9.09 mM for Rb2, 9.70 mM for Rg3(S), 11.4 mM for Rd and 12.9 mM for F2; and $V_{max}$ value from large to small was 23.2 mM/h for Rc, 16.6 mM/h for Rb1, 14.6 mM/h for Rb3, 14.3 mM/h for Rb2, 1.81mM/h for Rg3(S), 1.40 mM/h for Rd, and 0.41 mM/h for F2. According to the $V_{max}$ and $K_m$ values of the ginsenosidase type III, the hydrolysis speed of these substrates by the enzyme was Rc>Rb1>Rb3>Rb2>Rg3(S)>Rd>F2 in order.

• Journal of Microbiology and Biotechnology
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• v.23 no.4
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• pp.444-450
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• 2013

A Gram-negative, strictly aerobic, non-motile, non-spore-forming, and rod-shaped bacterial strain designated FW-$6^T$ was isolated from a freshwater sample and its taxonomic position was investigated by using a polyphasic approach. Strain FW-$6^T$ grew optimally at $10-42^{\circ}C$ and at pH 7.0 on nutrient and R2A agar. Strain FW-$6^T$ displayed ${\beta}$-glucosidase activity that was responsible for its ability to transform ginsenoside $Rb_1$ (one of the dominant active components of ginseng) to Rd. On the basis of 16S rRNA gene sequence similarity, strain FW-$6^T$ was shown to belong to the family Sphingomonadaceae and was related to Novosphingobium aromaticivorans DSM $12444^T$ (98.1% sequence similarity) and N. subterraneum IFO $16086^T$ (98.0%). The G+C content of the genomic DNA was 64.4%. The major menaquinone was Q-10 and the major fatty acids were summed feature 7 (comprising $C_{18:1}{\omega}9c/{\omega}12t/{\omega}7c$), summed feature 4 (comprising $C_{16:1}{\omega}7c/iso-C_{15:0}2OH$), $C_{16:0}$, and $C_{14:0}$ 2OH. DNA and chemotaxonomic data supported the affiliation of strain FW-$6^T$ to the genus Novosphingobium. Strain FW-$6^T$ could be differentiated genotypically and phenotypically from the recognized species of the genus Novosphingobium. The isolate that has ginsenoside converting ability therefore represents a novel species, for which the name Novosphingobium ginsenosidimutans sp. nov. is proposed, with the type strain FW-$6^T$ (= KACC $16615^T$ = JCM $18202^T$).

• Journal of Ecology and Environment
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• v.41 no.9
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• pp.271-280
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• 2017

Background: Soil microorganisms play key roles in nutrient cycling and are distributed throughout the soil profile. Currently, there is little information about the characteristics of the microbial communities along the soil depth because most studies focus on microorganisms inhabiting the soil surface. To better understand the functions and composition of microbial communities and the biogeochemical factors that shape them at different soil depths, we analyzed microbial activities and bacterial and fungal community composition in soils up to a 120 cm depth at a fallow field located in central Korea. To examine the vertical difference of microbial activities and community composition, ${\beta}$-1,4-glucosidase, cellobiohydrolase, ${\beta}$-1,4-xylosidase, ${\beta}$-1,4-N-acetylglucosaminidase, and acid phosphatase activities were analyzed and barcoded pyrosequencing of 16S rRNA genes (bacteria) and internal transcribed spacer region (fungi) was conducted. Results: The activity of all the soil enzymes analyzed, along with soil C concentration, declined with soil depth. For example, acid phosphatase activity was $125.9({\pm}5.7({\pm}1SE))$, $30.9({\pm}0.9)$, $15.7({\pm}0.6)$, $6.7({\pm}0.9)$, and $3.3({\pm}0.3)nmol\;g^{-1}\;h^{-1}$ at 0-15, 15-30, 30-60, 60-90, and 90-120 cm soil depths, respectively. Among the bacterial groups, the abundance of Proteobacteria (38.5, 23.2, 23.3, 26.1, and 17.5% at 0-15, 15-30, 30-60, 60-90, and 90-120 cm soil depths, respectively) and Firmicutes (12.8, 11.3, 8.6, 4.3, and 0.4% at 0-15, 15-30, 30-60, 60-90, and 90-120 cm soil depths, respectively) decreased with soil depth. On the other hand, the abundance of Ascomycota (51.2, 48.6, 65.7, 46.1, and 45.7% at 15, 30, 60, 90, and 120 cm depths, respectively), a dominant fungal group at this site, showed no clear trend along the soil profile. Conclusions: Our results show that soil C availability can determine soil enzyme activity at different soil depths and that bacterial communities have a clear trend along the soil depth at this study site. These metagenomics studies, along with other studies on microbial functions, are expected to enhance our understanding on the complexity of soil microbial communities and their relationship with biogeochemical factors.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.1
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• pp.41-48
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• 2000

A bacterial strain, designated as JK-43, producing extracellular cyclodextrin glucanotransferase (CGTase)[EC 2.4.1.19] was isolated from kimchi. The CGTase from isolated strain JK-43 showed the transglucosylation activity from soluble starch to L-ascorbic acid(AA) compared to those obtained from other strains. A main product formed by this reaction was identified as $2-O-{\alpha}-glucopyranosyl$ L-ascorbic acid(AA-2G) by testing its susceptibility to ${\alpha}-glucosidase$ hydrolysis, the HPLC profiles, and through the elementary analysis. the ${\beta}-CD,\;{\gamma}-CD$, potato starch and corn starch were identified to be suitable glucosyl donor for transglucosylation reaction on AA by CGTase. Acceptor specificity on AA-2G production was examined by use of AA, Iso-AA and AA-2P. Transglucosylation was observed toward AA-2P as well as AA and Iso-AA. The microorganism isolated from kimchi was identified as a strain of Bacillus sp. JK-43 based on the morphological, cultural, biochemical characteristics and partial 16SrDNA sequence analysis. The maximal CGTase production was observed in a medium containing 1.0% soluble starch, 1.0% yeast extract, 1.0% $Na_2CO_3\;0.1%\;K_2HPO_4,\;and\;0.02%\;MgSO_4{\cdot}7H_2O$ with initial pH 7.0. The strain was cultured at $37^{\circ}C$ for 26 hrs with reciprocal shaking.

• YAKHAK HOEJI
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• v.58 no.1
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• pp.71-79
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• 2014

Although Korean patients with type 2 diabetes mellitus (T2DM) are generally treated by western medicine, many of them strongly believe in the traditional oriental Sasang constitutional classification and depend on it for food, health supplements, and oriental medicines decision making. Sasang constitutional classification is a part of traditional Korean medicine that divides people into four constitutional types (Tae-Yang: TY, Tae-Eum: TE, So-Yang: SY, and So-Eum: SE), which differ in inherited characteristics such as appearance, personality traits, susceptibility to diseases, and drug responses. It is recommended for T2DM patients to control their blood glucose very well from early stages with drugs and diet. However, many T2DM patients respond differently to their drugs, even though they receive the same medicine. Therefore, the present study investigated whether Sasang constitutional type can explain the therapeutic differences between oral hypoglycemic agents (OHAs) therapy (mono, dual and triple drug therapy). Patients of 618 with T2DM diagnosis and Sasang constitutional type known who received both western and oriental medicine treatment in a hospital between April 2006 and April 2013 retrospectively studied. HbA1c (%) and blood glucose (mg/dl) levels before OHAs therapy and 3 month after were collected for metformin (MET) or sulfonylurea (SU) monotherapy, MET+SU dual therapy, MET+except SU (where was either alpha-glucosidase inhibitor, dipeptidyl peptidase-4 inhibitor, meglitinide or thiazolidinedione) dual therapy, and triple therapy, according to Sasang constitutional type. For statistical analysis, ANOVA was used and paired t-test by SPSS 19.0 where P values less than 0.05 were considered statistically significant. Pattern was similar levels of HbA1c and blood glucose and which was decreased in order of mono, MET+SU dual, MET+except SU dual and triple therapy. In all patients comparison, for the So-yang (SY) constitutional type, either monotherapy was less effective; for Te-eum (TE) type, MET+SU dual therapy was less effective while MET+except SU dual therapy was more effective and the triple therapy was less effective; and for So-eum (SE) type, the triple therapy was more effective. For the management of TE type it is recommended to use drugs except SU when dual therapy is needed, restrict triple therapy and consider dual and insulin therapy; for SY type it is recommended to follow current guidelines; and for SE type it is advisable to skip dual therapy and start the triple therapy early. Finally, the therapeutic response to OHAs is different among Korean T2DM patients with different Sasang constitutional types. Taken together, the choice of effective OHAs therapy for each type is necessary in order to minimize the poor control of blood glucose level, the risk of complications, and the costs from a failure of therapy.

• Food Science and Preservation
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• v.22 no.1
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• pp.108-118
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• 2015

To raise the added value of the fruits of Cudrania tricuspidata, Cudrania tricuspidata vinegar was produced and examined for its fermentation conditions. Forty nine acetic acid bacteria with resistance against acetic acid, ethanol, and sulfide as high acetic acid producers were isolated from fermented foods and identified as Acetobacter indonesiensis, A. cerevisiae, A. orientalis, A. tropicalis, A. fabarum, A. pasteurianus, and A. syzygii based on the results of the analysis of the 16S rRNA gene sequences. Among them, two GRAS strains, A. pasteurianus SCMA5 and SCMA6, were finally selected for the production of acetic acid. Optimal vinegar productions were obtained from the medium containing 40% (v/v) fruit juice of Cudrania tricuspidata and 5% (v/v) ethanol at $25^{\circ}C$ for 72 hr. The sensory panel preferred the vinegar fermented with the SCMA06 to that with the SCM05 strain. The radical scavenger capacity of DPPH was 53% higher than that of the control in the vinegar fermented with the SCMA06 strain. The ${\alpha}$-glucosidase inhibitor activity as an index of the antidiabetic drug showed 91% inhibition, which is higher than that of acabose. This study will be helpful for the scale-up production of vinegar with the fruit of Cudrania tricuspidata.

• Korean Journal of Food Science and Technology
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• v.44 no.1
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• pp.61-68
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• 2012

Sikhae is a traditional Korean fermented seafood with a 7-10% salt concentration. Consumers have begun to look for low-salt food because excess salt is known to cause hypertension and gastric cancer. The quality characteristics of low-salt squid sikhae were investigated at different fermentation temperatures and periods, so as to determine its shelflife. The shelf-life of the low-salt (5%) squid sikhae at $-1^{\circ}C$ based on pH was 142 days. The functional activities of the ethanol extract of squid sikhae such as its antioxidant activity and inhibitions on ${\alpha}$-glucosidase, ${\beta}$-glucuronidase, and elastase were stronger than those of the water extract. Based on the results of sensory evaluation, the low-salted squid sikhae was very similar to fermented seafood. In conclusion, low-salt sikhae is commercially viable.

• Korean Journal of Medicinal Crop Science
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• v.16 no.3
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• pp.155-160
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• 2008

Ginsenosides have been regarded as the principal components, responsible for the pharmacological and biological activities of ginseng. Absorption of major ginsenosides at the gastrointestinal tract was extremely low, when ginseng taken orally. In order to improve the absorption and bioavailability, transformation of major ginsenosides into more active and valuable minor ginsenoside is much required. In this present study, We isolated a lactic acid bacteria Leuconostoc fallax LH3 from the Korean fermented food Kimchi, which have higher ${\beta}$-glucosidase activity. Using the ethanol precipitated curd enzyme of Leuconostoc fallax LH3, we investigated the biotransformation of ginsenoside Rd at different experimental condition to increase transformation. The maximum convertion was supported at 30 $^{\circ}C$ and decreased when temperatures increased. In order to optimize the effect of pH, the curd enzyme was mixed 20 mM sodium phosphate buffer (pH 3.5 to pH 8.0). Ginsenoside Rd was almost hydrolyzed between pH 7.0 and pH 9.0, but not hydrolyzed above pH 10.0. Ginsenoside Rd was hydrolyzed after 24 hrs incubation, but whereas the ginsenoside F2 was appeared from 36 hrs, and all ginsenoside Rd was transformed to F2 after the 60 hrs incubation. Based on this study, the curd enzyme of Leuconostoc fallax LH3 transformed the ginsenoside Rd at the 30$^{\circ}C$ and the pH optimum of 7.0 to 9.0 after the 60 hrs incubation time.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.10
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• pp.1439-1445
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• 2010

In this study, we investigated the inhibition of phyto-extract mixture (PEM) in several digestive enzymes ($\alpha$-amylase, $\alpha$-glucosidase and lipase) for anti-obesity. The current study also examined the effects of PEM on adiposity and serum lipid levels in obese mice fed with high fat diet. ICR male mice weighing $33{\pm}1.1\;g$ were randomly divided into three groups, one normal diet group (control, ND group) and two high fat diet groups with or without PEM supplement (HFD group and PEM group). The mice were fed the PEM experimental for 6 weeks and then they were sacrificed. The results showed that the final weight, weight gain, food efficiency ratio and body fat were decreased by the addition of PEM compared to those of HFD group. White adipose tissue weights of epididymal, mesenteric and retroperitoneal areas in the PEM group were reduced to 31.2%, 8.8%, and 37.8%, respectively, compared to the HFD group. The levels of serum triglyceride, total cholesterol, LDL-cholesterol in the PEM group were significantly lower than those of HFD group. The body weight gain and food efficiency ratio of PEM group were significantly lower compared with those of HFD group. From the above results, the PEM may be effective material for anti-obesity through reducing serum triglyceride and body fats as well as decreasing body weight.

• Korean Journal of Medicinal Crop Science
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• v.21 no.5
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• pp.361-371
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• 2013

This study was performed to determine the antimelanogenic effect and tyrosinase inhibitory activities of anthocyanin rich fraction (AN-SLP) from Liriope platyphylla Wang et Tang seeds. Anthocyanins isolated from L. platyphylla seeds revealed the presence of four major anthocyanin components, which were tentatively identified as delphinidin-3-Oglucoside, delphinidin-3-O-rutinoside, petunidin-3-O-rutinoside, and malvidin-3-O-rutinoside using semipreparative HPLC, $^1H$-NMR, $^{13}C$ NMR, FAB-MS and LC/ES-MS. The inhibitory effect of AN-SLP on tyrosinase activity was studied using in vitro (against mushroom tyrosinase) and ex vivo (against B16 melanoma cell tyrosinase) models. Cellular tyrosinase activity was decreased by AN-SLP treatment in B 16 melanoma cells through dose dependent manner, but AN-SLP did not inhibit mushroom tyrosinase and L-DOPA oxidation directly. AN-SLP showed melanin inhibition by 53.2% at 50 ${\mu}g/m{\ell}$ which was 0.7 times more efficient than the antimelanogenic effect of commercial arbutin and kojic acid (36.5%) also did not show cell toxicity. Additionally, AN-SLP inhibited the activity of ${\alpha}$-glucosidase and the glycosylation of tyrosinase in melanoma cell. The resulting unsaturated glycosylation of tyrosinase makes it unstable and disturb correct transportation. From theses results, we conclude that AN-SLP could be used as anti-melanogenic agent for skin whitening.