• Journal of Microbiology and Biotechnology
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• 제20권2호
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• pp.340-345
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• 2010

The culture variables were optimized to increase 1,3-dihydroxyacetone (DHA) production by Gluconohacter oxydans ZJB09112 in shake flasks and bubble column bioreactors. After fermentation in the optimized medium (g/l: yeast extract 5, glycerol 2.5, mannitol 22.5, $K_2HPO_4$ 0.5, $KH_2PO_4$ 0.5, $MgSO_4{\cdot}7H_2O$ 0.1, $CaCO_3$ 2.0, pH 5.0), when five times of glycerol feeding were applied, $161.9{\pm}5.9\;g/l$ of DHA was attained at a $88.7{\pm}3.2%$ conversion rate of glycerol to DHA.

• Journal of Microbiology and Biotechnology
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• 제26권11호
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• pp.1908-1917
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• 2016

Wild strain L-6 was subjected to combined mutagenesis, including UV irradiation, atmospheric and room temperature plasma, and ion beam implantation, to increase the yield of 1,3-dihydroxyacetone (DHA). With application of a high-throughput screening method, mutant Gluconobacter oxydans I-2-239 with a DHA productivity of 103.5 g/l in flask-shake fermentation was finally obtained with the starting glycerol concentration of 120 g/l, which was 115.7% higher than the wild strain. The cultivation time also decreased from 54 h to 36 h. Compared with the wild strain, a dramatic increase in enzyme activity was observed for the mutant strain, although the increase in biomass was limited. DNA and amino acid sequence alignment revealed 11 nucleotide substitutions and 10 amino acid substitutions between the sldAB of strains L-6 and I-2-239. Simulation of the 3-D structure and prediction of active site residues and PQQ binding site residues suggested that these mutations were mainly related to PQQ binding, which was speculated to be favorable for the catalyzing capacity of glycerol dehydrogenase. RT-qPCR assay indicated that the transcription levels of sldA and sldB in the mutant strain were respectively 4.8-fold and 5.4-fold higher than that in the wild strain, suggesting another possible reason for the increased DHA productivity of the mutant strain.

• 대한화장품학회지
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• 제42권4호
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• pp.413-420
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• 2016

하이드록시 산(hydroxy acid, HA)은 피부 각질층에 대한 박리효과로 노화방지와 피부 보습을 높이는데 효과를 보여, 피부 외용제와 화장품으로서 많은 활용을 하고 있다. 그 중에서 가장 효과적으로 빠른 시간 내에 나타나는 각질 박리는 화장품 제형 pH에 의해 효과를 보이는 것으로 많은 보고가 있다. 그러나 pH에 의한 자극, 부작용에 의한 염려로 인해 사용에 많은 어려움이 있다. 본 연구의 목적은 피부 각질층에 (1) 하이드록시 산의 농도와 (2) 종류, (3) pH를 변화시킨 화장품을 인체 피부에 도포하여 각질 박리 효과에 대한 영향을 측정하는 데에 있다. 건강한 성인 22명을 대상으로 하박 내측에 DHA (dihydroxyacetone), DC (dansyl chloride)로 피부 표면 각질을 염색하여, 시험제품을 도포한 뒤 각질박리 효과를 측정하였다. (1) GA (glycolic acid)의 농도에 따라 각질 박리 효과는 농도 의존적으로 증가하는 것으로 나타났다. (2 )하이드록시 산의 종류에 따라 pH를 산성과 중성으로 제조한 제품을 대상으로 각질 박리 효과를 측정한 결과, 중성 pH의 GA는 각질 박리 효과가 나타나지 않았다. 이에 반해 SA (salicylic acid)는 산성 pH와 중성 pH에서 모두 통계적으로 유의한 각질 박리 효과가 나타났다. (3) 중성 pH의 SA는 DHA와 DC로 염색한 피부 표면에서 모두 우수한 각질 박리 효과를 나타내었다. 이러한 결과는 pH에 민감한 사람들에게 각질 박리 효과를 기대하는 화장품을 사용할 수 있는 기회를 제공하며, 피부 장벽의 손상 없이 안전한 화장품을 제조할 수 있을 것이라 사료된다.

• 한국식품과학회지
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• 제20권1호
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• pp.119-124
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• 1988

식품의 안전성 평가를 위한 기초자료를 얻기 위하여, 식품의 가공, 저장 및 조리중에 식품성분간의 상호반응인 Maillard 반응을 이용하여 당의 분해로 생성되는 각종 카르보닐화합물을 강력한 돌연변이원성물질로 알려진 Trp-P-1, Trp-P-2, Glu-P-1, Glu-P-2 및 IQ에 각각 작용시켜서 이들 물질의 돌연변이성 억제효과를 연구 검토하였다. 그 결과, 카르보닐화합물에 의하여 돌연변이원성물질의 돌연변이원 활성이 크게 억제되었다. 사용한 카르보닐화합물중 ${\alpha}$-hydroxycarbonyl 화합물의 경우, glyceraldehyde, glycolaldehyde 및 dihydroxyacetone에서 돌연변이원성 억제효과가 크게 나타났다. ${\alpha}$-dicarbonyl 화합물의 경우, diacetyl에서 그 억제효과가 우수한 것으로 나타서, 전반적으로 ${\alpha}$-dicarbonyl 화합물이 ${\alpha}$-hydroxycarbonyl 화합물보다 돌연변이성 억제효과가 높게 나타났다. 한편, 공시한 카르보닐화합물 단독으로는 돌연변이 성을 나타내었으나, Trp-P-1등의 돌연변이원성물질과의 상호반응로 이들 두 물질의 돌연변이성이 동시에 소실되는 것이 입증되었다.

• Journal of Microbiology and Biotechnology
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• 제30권2호
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• pp.271-278
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• 2020

Glycerol dehydrogenase (GlyDH) catalyzes the oxidation of glycerol to dihydroxyacetone (DHA), which is the first step in the glycerol metabolism pathway. GlyDH has attracted great interest for its potential industrial applications, since DHA is a precursor for the synthesis of many commercially valuable chemicals and various drugs. In this study, GlyDH from Klebsiella pneumoniae (KpGlyDH) was overexpressed in E. coli and purified to homogeneity for biochemical and molecular characterization. KpGlyDH exhibits an exclusive preference for NAD⁺ over NADP⁺. The enzymatic activity of KpGlyDH is maximal at pH 8.6 and pH 10.0. Of the three common polyol substrates, KpGlyDH showed the highest k_cat/K_m value for glycerol, which is three times higher than for racemic 2,3-butanediol and 32 times higher than for ethylene glycol. The k_cat value for glycerol oxidation is notably high at 87.1 ± 11.3 sec^-1. KpGlyDH was shown to exist in an equilibrium between two different oligomeric states, octamer and hexadecamer, by size-exclusion chromatography analysis. KpGlyDH is structurally thermostable, with a T_m of 83.4℃, in thermal denaturation experiment using circular dichroism spectroscopy. The biochemical and biophysical characteristics of KpGlyDH revealed in this study should provide the basis for future research on its glycerol metabolism and possible use in industrial applications.

• Archives of Pharmacal Research
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• 제24권2호
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• pp.95-99
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• 2001

Novel fluoro-substituted apio dideoxyuncleoside(($\pm$)-3a and ($\pm$)-3b) were efficiently synthesized stalling from 1,3-dihydroxyacetone via Horner-Emmons olefination as a key step. Cyclization of fluoro ester ($\pm$)-6 under acidic conditions to the fluorolactone was smoothly proceeded in favor of trans-fluorolactone due to the favorable transition state with equatorial hydroxymethyl substituent. Unfortunately the final nucleosides($\pm$) -3a and ($\pm$)-3b were found to be inactive against several viruses such as HIV-1, HSV- I , HSV-2 and HCMV.

• 한국식품과학회지
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• 제21권3호
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• pp.435-440
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• 1989

식품의 안전성 평가를 위한 기초자료로서 각종 활성산소 소거제 및 환원제를 사용하여 식품성분간의 상호반응에 의하여 당의 분해로 생성되는 저분자 카르보닐 화합물의 돌연변이원성과 그 억제기구를 검토하였다. 그 결과, 카르보닐화합물의 돌연변이원성은 glyceraldehyde 등의 ${\alpha}-hydroxycarbonyl$ 화합물보다 glyoxal등의 ${\alpha}-dicarbonyl$ 화합물이 큰 것으로 나타났으며, 그 중에서 methyl glyoxal이 가장 큰 것으로 밝혀졌다. 각종 활성산소 소거제 및 환원제의 돌연변이원성 억제작용은 cysteine, glutathione 및 sodium bisulfite의 억제작용이 큰 것으로 나타나 이들 카르보닐화합물의 돌연변이원성은 주로 산화에 의해 생성되는 일중항산소$(^1O_2)$ 및 그 자체의 반응성에 크게 기인하는 것으로 밝혀졌다. 또한, 이들 카르보닐화합물의 돌연변이원성은 첨가된 활성산소 소거제에 의하여 카르보닐화합물의 자동산화로 생성된 일중항산소, 수산라디칼, 과산화수소 및 superoxide anion 등의 소거 및 환원제에 의하여 카르보닐화합물의 반응성의 소실로 인하여 억제되는 것으로 생각된다. 한편, 공시한 각 활성산소 소거제 및 환원제 단독으로는 돌연변이원성이 없는 것으로 나타났다.

• 미생물학회지
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• 제31권2호
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• pp.99-104
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• 1993

Two strains of the gram-negative acetic acid bacteria, Acetobacter sp. strain CS2- AND CS5, were isolated form the traditional raw rice wine vinegar of Haenam area. The strains oxidized ethanol to acetic acid and over-oxidized acetate and lactate to $CO^{2}$ and $H ^{2}$O. They produced 2-ketogluconic acid from glucose but did not produce .gamma.-pyrones from glucose and dihydroxyacetone from glycerol. The CS strains possessed ubiquinone-9 as a major isoprenoid quinone and contained straight-chain $C_{18 :1}$, $_C{16 : 0}$, and $C _{14 : 0}$ fatty acids. The DNA base composition of the CS2 and CS5 strains was 56.2 and 57.3 mole% G + C, respectively. The isolates were grown well on methanol, gluconate, erythritol, raffinose, dulcitol and xylitol as sole sources of carbon and energy which are different from those of other Acetobacter species and producedd acid from sucrose, glycerol, fructose, inositol, mannitol, and ribose.

• Journal of Microbiology and Biotechnology
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• 제30권6호
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• pp.903-911
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• 2020

Addition of probiotics to yogurt with desired health benefits is gaining increasing attention. To further understand the effect of probiotic Lactobacillus plantarum on the quality and function of fermented milk, probiotic fermented milk (PFM) made with probiotic L. plantarum K25 and yogurt starter (L. delbrueckii ssp. bulgaricus and Streptococcus thermophilus) was compared with the control fermented milk (FM) made with only the yogurt starter. The probiotic strain was shown to survive well with a viable count of 7.1 ± 0.1 log CFU/g in the PFM sample after 21 days of storage at 4℃. The strain was shown to promote formation of volatiles such as acetoin and 2,3-butanediol with milk fragrance, and it did not cause post-acidification during refrigerated storage. Metabolomics analysis by GC-MS datasets coupled with multivariate statistical analysis showed that addition of L. plantarum K25 increased formation of over 20 metabolites detected in fermented milk, among which γ-aminobutyric acid was the most prominent. Together with several other metabolites with relatively high levels in fermented milk such as glyceric acid, malic acid, succinic acid, glycine, alanine, ribose, and 1,3-dihydroxyacetone, they might play important roles in the probiotic function of L. plantarum K25. Further assay of the bioactivity of the PFM sample showed significant (p < 0.05) increase of ACE inhibitory activity from 22.3% at day 1 to 49.3% at day 21 of the refrigerated storage. Therefore, probiotic L. plantarum K25 could be explored for potential application in functional dairy products.

• BMB Reports
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• 제36권2호
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• pp.159-166
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• 2003

Cytoplasmic $\alpha$-glycerol-3-phosphate dehydrogenase from fruit-bat-breast muscle was purified by ion-exchange and affinity chromatography. The specific activity of the purified enzyme was approximately 120 units/mg of protein. The apparent molecular weight of the native enzyme, as determined by gel filtration on Sephadex G-100 was $59,500{\pm}650$ daltons; its subunit size was estimated to be $35,700{\pm}140$ by SDS-polyacrylamide gel electrophoresis. The true Michaelis-Menten constants for all substrates at pH 7.5 were $3.9{\pm}0.7\;mM$, $0.65{\pm}0.05\;mM$, $0.26{\pm}0.06\;mM$, and $0.005{\pm}0.0004\;mM$ for L-glycerol-3-phosphate, $NAD^+$, DHAP, and NADH, respectively. The true Michaelis-Menten constants at pH 10.0 were $2.30{\pm}0.21\;mM$ and $0.20{\pm}0.01\;mM$ for L-glycerol-3-phosphate and $NAD^+$, respectively. The turnover number, $k_{cat}$, of the forward reaction was $1.9{\pm}0.2{\times}10^4\;s^{-1}$. The treatment of the enzyme with 5,5'-dithiobis-2-nitrobenzoic acid (DTNB) under denaturing conditions indicated that there were a total of eight cysteine residues, while only two of these residues were reactive towards DTNB in the native enzyme. The overall results of the in vitro experiments suggest that $\alpha$-glycerol-3-phosphate dehydrogenase of the fruit bat preferentially catalyses the reduction of dihydroxyacetone phosphate to glycerol-3-phosphate.