• Mycobiology
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• 제42권4호
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• pp.368-375
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• 2014

Red ginseng (Panax ginseng), a Korean traditional medicinal plant, contains a variety of ginsenosides as major functional components. It is necessary to remove sugar moieties from the major ginsenosides, which have a lower absorption rate into the intestine, to obtain the aglycone form. To screen for microorganisms showing bioconversion activity for ginsenosides from red ginseng, 50 yeast strains were isolated from Korean traditional meju (a starter culture made with soybean and wheat flour for the fermentation of soybean paste). Twenty strains in which a black zone formed around the colony on esculin-yeast malt agar plates were screened first, and among them 5 strains having high ${\beta}$-glucosidase activity on p-nitrophenyl-${\beta}$-D-glucopyranoside as a substrate were then selected. Strain JNO301 was finally chosen as a bioconverting strain in this study on the basis of its high bioconversion activity for red ginseng extract as determined by thin-layer chromatography (TLC) analysis. The selected bioconversion strain was identified as Candida allociferrii JNO301 based on the nucleotide sequence analysis of the 18S rRNA gene. The optimum temperature and pH for the cell growth were $20{\sim}30^{\circ}C$ and pH 5~8, respectively. TLC analysis confirmed that C. allociferrii JNO301 converted ginsenoside Rb1 into Rd and then into F2, Rb2 into compound O, Rc into compound Mc1, and Rf into Rh1. Quantitative analysis using high-performance liquid chromatography showed that bioconversion of red ginseng extract resulted in an increase of 2.73, 3.32, 33.87, 16, and 5.48 fold in the concentration of Rd, F2, compound O, compound Mc1, and Rh1, respectively.

• 한국균학회소식:학술대회논문집
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• 한국균학회 2016년도 춘계학술대회 및 임시총회
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• pp.11-11
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• 2016

Penicillium species are commonly isolated from various outdoor and indoor environments, including marine environments such as sponges, algae and sand. Penicillium is especially important because numerous bioactive compounds have been isolated. Penicillium was the most common species in intertidal zone in Korea, however the diversity and ecological roles of Penicillium in intertidal zone are not clarified. We explored diversity and ecological roles of marine-derived Penicillium from tidal flat and sea sand in Korea. The diversity of marine-derived Penicillium from Korea was investigated using both culture-dependent and culture-independent approach by ${\beta}$-tubulin sequence. In addition, we evaluated optimal temperature, halo-tolerance, and enzyme activity of Penicillium strains, such as extracellular alginase, endoglucanase, ${\beta}$-glucosidase, and protease. For culture-dependent approach, a total of 182 strains of 62 Penicillium species were isolated, with 53 species being identified. The most common species was Penicillium oxalicum, followed by P. crustosum, P. brasilianum, P. koreense, and P. griseofulvum. Species richness and composition were not significantly different by season, substrates, and seaside. For culture-independent approach using Illumina sequencing, 73 OTUSs were detected. The most frequently observed species was P. antarcticum, followed by P. koreense, P. crustosum, and P. brevicompactum. Diversity of Penicillium was higher during winter season than during summer season and in western sea than in southern sea, respectively. Community structure was significantly different by season and sea side. 52 species were detected by both methods. Unique species were isolated from each of methods - 10 from culture methods and 21 from Illumina sequencing. Furthermore, salinity adaption of the Penicillium varied depending on species. Many Penicillium species showed endoglucanase, ${\beta}$-glucosidase, and protease activity. Some species including P. paneum and P. javanicum degraded the polycyclic aromatic hydrocarbons. Thus, our results demonstrate that intertidal zone in Korea harbors diverse Penicillium community and marine-derived Penicillium play important ecological roles as decomposers of organic material in marine environments.

• 한국균학회지
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• 제18권4호
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• pp.209-217
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• 1990

Aspergillus niger에 있어서 여러가지 섬유질 기질이 세포내외의 섬유질 분해효소계의 생합성 및 동질효소의 양상에 미치는 영향을 조사하였다. Cellulase 및 xylanase 효소계의 생합성은 사용된 기질에 따라 큰 차이가 있었으며, 특히 cellulase 효소계의 CMCase와 ${\beta}-glucosidase$는 혼합기질의 사용시 효소활성이 증진되는 기질의 공조효과를 보였다. 또한 기질에 따라 섬유질분해효소계 동질효소의 생성 양상이 다르게 나타났으나 세포내외간 동질효소 양상의 차이는 발견되지 않았으며 배양시간에 따른 동질효소의 변화도 없었다. 이러한 결과들은 A. niger의 cellulase 및 xylanase효소계의 생합성은 기질에 의한 효소의 유도 수준에서 상호 연관적으로 조절되어짐을 보여주며, 세포외 효소에서 나타나는 multiple-isozyme의 형성이 합성되어진 효소의 post-secretional modification에 의한 결과라기 보다는 각각의 유전자 발현 결과에 의한 것임을 시사한다.

• Natural Product Sciences
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• 제18권1호
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• pp.47-51
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• 2012

Among 38 Vietnamese medicinal plant extracts investigated for their ${\alpha}$-glucosidase inhibitory activity, 35 extracts showed $IC_{50}$ values below $250{\mu}g/mL$. The MeOH extracts of the heartwood of Oroxylum indicum, the seeds of Caesalpinia sappan, and the fruits of Xanthium strumarium exhibited strong ${\alpha}$-glucosidase inhibitory activity with $IC_{50}$ values less than $50{\mu}g/mL$. Fractionation of the MeOH extract of the heartwood of O. indicum led to the isolation of oroxylin A (1), oroxyloside (2), hispidulin (3), apigenin (4), ficusal (5), balanophonin (6), 2- (1-hydroxymethylethyl)-4H,9H-naphtho[2,3-b]furan-4,9-dione (7), salicylic acid (8), p-hydroxybenzoic acid (9), protocatechuic acid (10), isovanillin (11), and ${\beta}$-hydroxypropiovanillon (12). Compounds 1 - 3, 5, 6, 8, 10, and 12 showed more potent activities, with $IC_{50}$ values ranging from 2.13 to $133.51{\mu}M$, than a positive control acabose ($IC_{50}$, $241.85{\mu}M$). The kinetic study indicated that oroxyloside (2) displayed mixed-type inhibition with inhibition constant (Ki) was $3.56{\mu}M$.

• Journal of Microbiology and Biotechnology
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• 제31권7호
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• pp.1035-1043
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• 2021

Although engineered Saccharomyces cerevisiae fermenting cellobiose is useful for the production of biofuels from cellulosic biomass, cellodextrin accumulation is one of the main problems reducing ethanol yield and productivity in cellobiose fermentation with S. cerevisiae expressing cellodextrin transporter (CDT) and intracellular β-glucosidase (GH1-1). In this study, we investigated the reason for the cellodextrin accumulation and how to alleviate its formation during cellobiose fermentation using engineered S. cerevisiae fermenting cellobiose. From the series of cellobiose fermentation using S. cerevisiae expressing only GH1-1 under several culture conditions, it was discovered that small amounts of GH1-1 were secreted and cellodextrin was generated through trans-glycosylation activity of the secreted GH1-1. As GH1-1 does not have a secretion signal peptide, non-conventional protein secretion might facilitate the secretion of GH1-1. In cellobiose fermentations with S. cerevisiae expressing only GH1-1, knockout of TLG2 gene involved in non-conventional protein secretion pathway significantly delayed cellodextrin formation by reducing the secretion of GH1-1 by more than 50%. However, in cellobiose fermentations with S. cerevisiae expressing both GH1-1 and CDT-1, TLG2 knockout did not show a significant effect on cellodextrin formation, although secretion of GH1-1 was reduced by more than 40%. These results suggest that the development of new intracellular β-glucosidase, not influenced by non-conventional protein secretion, is required for better cellobiose fermentation performances of engineered S. cerevisiae fermenting cellobiose.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2001년도 추계학술발표대회
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• pp.882-885
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• 2001

The cells of Lactobacillus plantarum MY4 isolated from the human feces were treated for 24 h in artificial bile after incubation for 2 h in artificial gastric juice and final number of the strain was reached to around $3.1{\times}10^8$ CFU/ml. In test of API ZYM kit, ${\beta}$-glucuronidase or ${\beta}$-glucosidase were not produced by L. plantarum MY4. However, ${\beta}$-galactosidase were weakly produced by it, which they would be alleviated the lactose intolerance. L. plantarum MY4 were resistant to antibiotics such as nisin, tetracycline, streptomycin, rifamycin, doxycycline, roxithromycin, chloramphenicol, nystatin, erythromycin, ciprofloxacin and gentamycin. L. plantarum MY4 was affected by alcohol concentration up to 8%, but more than 16%, their growth was not affected significantly. L. plantarum MY4 was shown to inhibit the growth of Listeria monocytogenes ATCC 19111 completely within 24 h of incubation, which indicates its bactericidal nature. Thus, L plantarum MY4 show promise as a probiotic strain because of its characteristics.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XII)
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• pp.209-212
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• 2003

본 연구는 고수율의 아라비녹실란을 얻기위해 필수요소인 Lentinus edodes의 액체배양을 통해 생산되어지는 탄수화물 복합효소의 생산수율을 증대시키는데 그 목적이 있다. 그러기 위해 탄수화물 복합효소의 생산에 배지성분이 미치는 영향을 검토 하였다.

• Journal of Microbiology and Biotechnology
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• 제16권2호
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• pp.200-204
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• 2006

The enzymology of an activated sludge system for a petroleum wastewater purification process was investigated. Leucine-aminopeptidase (L-AMP), ${\beta}$-glucosidase (${\beta}-GLC$), and lipase (LIP) were selected for the study. It was found that more than 81.7% of enzymatic activity was associated with microbial cells in the activated sludge floc. The metabolic response of a mixed microbial population to increased phenol concentration showed that L-AMP activity increased in the activated sludge, whereas activities of ${\beta}-GLC$ and LIP decreased, due to the inhibitory effect of the phenol which varied from 100 mg/l to 500 mg/l.

• Journal of Microbiology and Biotechnology
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• 제10권5호
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• pp.638-642
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• 2000

A ${\beta}-glycosidase$ enzyme with $\beta$-D-fucosidase, ${\beta}-D-galactosidase$, and $\beta$-D-glucosidase activities has been purified from Thermus caldophilus GK24. The enzyme was monomeric with a molecular mass of 49 kDa, as evidenced by SDS-PAGE. The $K_m$ values for p-nitrophenyl ${\beta}-D-fucopyranoside$ (p-NPFuc), p-nitrophenyl ${\beta}-D-galactopyranoside$ (p-NPGal), and p-nitrophenyl ${\beta}-D-glucopyranoside$ (p-NPGlu) were 0.23 mM, 6.25 mM, and 0.28 mM, respectively. The enzyme showed optimal pH ranging between 5.5-6.5 and maximum temperature in the range of $85-90^{\circ}C$ for all the above mentioned activities. The half-life of the enzyme in sodium phosphate buffer (pH 6.0) at $80^{\circ}C$ was approximately 7 h. The p-NPGal hydrolyzing activity of Tca ${\beta}-glycosidase$ was strongly activated by L-histidine, while the p-NPFuc and p-NPGlu hydrolyzing activities of Tca ${\beta}-glycosidase$ were not affected at all by the amino acid. These results suggest differences in the conformation or in the reactive residues at the active site of Tca ${\beta}-glycosidase$.

• Journal of Dairy Science and Biotechnology
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• 제35권4호
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• pp.221-231
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• 2017

본 연구는 김치로부터 비만 억제능력이 있는 젖산균을 분리 및 동정하고, 이 균주의 생리적 특성을 규명하여 상업적으로의 이용가능성을 검토하고자 실시하였다. 이를 위해 Modified MRS 분별배지를 사용하여 노란색 집락을 형성하는 균주를 대상으로 각각 ${\alpha}-amylase$ inhibitory activity, ${\alpha}-glucosidase$ inhibitory activity와 lipase inhibitory activity가 우수한 균주를 선발한 결과 K6 균주가 최종 선발되었다. K6 균주는 ${\alpha}-amylase$ 억제활성 $96.78{\pm}3.29%$, ${\alpha}-glucosidase$ 억제활성 $92.55{\pm}9.62%$, lipase 억제활성 $85.17{\pm}0.79%$, 지방분화 억제활성 $27.4{\pm}1.4%$로 나타났으며, 동정결과 Lactobacillus plantarum으로 판명되었고, Lactobacillus plantarum K6으로 명명하였다. L. plantarum K6은 답즙산과 산성의 pH에서 모두 우수한 생존력을 나타내었고, 효소활성은 전반적으로 낮았으나 arylamidase와 ${\beta}-galactosidase$에 대해 비교적 높은 효소 활성을 나타내었다. 항생제 내성 실험 결과 vancomycin, ampicillin, polymyxin B에 내성이 있는 반면 erythromycin에 감수성을 나타냈으며, Escherichia coli, Salmonella Typhimurium, Listeria monocytogenes와 Staphyloccous aureus에 대해 각각 51.8%, 42.4%, 61.6%와 54.9%의 억제 효과를 지니고 있는 것으로 나타났다. 또한, 아민을 생성하지 않으며, 장부착성은 대조구인 L. rhamnosus GG보다 우수하였다.