• Journal of Microbiology and Biotechnology
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• v.29 no.2
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• pp.191-199
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• 2019

We inoculated different combinations of three starter candidates, Bacillus licheniformis, Staphylococcus succinus, and Tetragenococcus halophilus, into sterilized soybeans to predict their contributions to volatile compound production through soybean fermentation. Simultaneously, we added NaCl to soybean cultures to evaluate its effect on the volatile compounds profile. Cells in soybean cultures (1.5% NaCl) nearly reached their maximum growth in a day of incubation, while cell growth was delayed by increasing NaCl concentrations in soybean cultures. The dominance of B. licheniformis and S. succinus in the mixed cultures of three starter candidates switched to T. halophilus as the NaCl concentration increased from 1.5% to 14% (w/w). Seventeen volatile compounds were detected from the control and starter candidate-inoculated soybean cultures with and without the addition of NaCl. Principal component analysis of these volatile compounds concluded that B. licheniformis and S. succinus made major contributions to producing a specific volatile compound profile from soybean cultures where both species exhibited good growth. 3-Hydroxybutan-2-one, butane-2,3-diol, and 2,3,5,6-tetramethylpyrazine are specific odor notes for B. licheniformis, and 3-methylbutyl acetate and 2-phenylethanol are specific for S. succinus. Octan-3-one and 3-methylbutan-1-ol were shown to be decisive volatile compounds for determining the involvement of S. succinus in the soybean culture containing 7% NaCl. 3-Methylbutyl acetate and 3-methylbutan-1-ol were also produced by T. halophilus during soybean fermentation at an appropriate level of NaCl. Although S. succinus and T. halophilus exhibited growth on the soybean cultures containing 14% NaCl, species-specific volatile compounds determining the directionality of the volatile compounds profile were not produced.

• Korean Journal of Clinical Laboratory Science
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• v.47 no.1
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• pp.6-10
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• 2015

Photodynamic therapy (PDT) apply photosensitizers and light. The purpose of this study was to evaluate the in vitro efficacy of PDT using blue LED (light emitting diode) with photofrin and radachlorin for Propionibacterium acnes. The colony forming units method was used to assess the antibacterial activity. Suspension (1 mL) containing P. acnes at $1{\times}10^5CFU/mL$ were prepared and then 2 fold serial diluted to $12.5{\mu}g/mL$ from $50{\mu}g/mL$ concentration of photofrin and radachlorin. After 60 minutes incubation, light was irradiated for 10 to 30 minutes using the following light source of wavelength 460 nm, each energy density 36, 72 and $108J/cm^2$. Bacterial growth was evaluated after 72 hours incubation in a Phenylethanol Blood Agar (PEBA) culture. In addition, flow cytometric analysis were performed to measure the live cell after PDT. Also transmission electron microscopy (TEM) was employed to evaluate the effect of pathogens by PDT. The PDT Group was perfectly killed to all kind of photosensitizers dose of $12.5{\mu}g/mL$ with irradiation of 10 minutes. Also other Groups were killed to all kind of photosensitizers dose of $6.25{\mu}g/mL$ with irradiation time of 20 and 30 minutes. The flow cytometry showed a lower number of viable bacteria in the PDT group compared to the control group. The images of the TEM results were showed in cytoplasmic membrane damage and partially deformed to cell morphologies. These results suggest that radachlorin and photofrin combine blue LED PDT can be effectively treated when was proved treatment for acnes therapy.

• Journal of Microbiology and Biotechnology
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• v.23 no.1
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• pp.29-35
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• 2013

A Nodulisporium sp. (Hypoxylon sp.) has been isolated as an endophyte of Thelypteris angustifolia (Broadleaf Leaf Maiden Fern) in a rainforest region of Central America. It has been identified both on the basis of its morphological characteristics and by scanning electron microscopy as well as ITS sequence analysis. The endophyte produces volatile organic compounds (VOCs) that have both fuel (mycodiesel) and use for biological control of plant disease. When grown on potato dextrose agar, the organism uniquely produces a series of ketones, including acetone; 2-pentanone; 3-hexanone, 4-methyl; 3-hexanone, 2,4-dimethyl; 2-hexanone, 4-methyl, and 5-hepten, 2-one and these account for about 25% of the total VOCs. The most abundant identified VOC was 1,8 cineole, which is commonly detected in this group of organisms. Other prominent VOCs produced by this endophyte include 1-butanol, 2-methyl, and phenylethanol alcohol. Moreover, of interest was the presence of cyclohexane, propyl, which is a common ingredient of diesel fuel. Furthermore, the VOCs of this isolate of Nodulisporium sp. were selectively active against a number of plant pathogens, and upon a 24 h exposure caused death to Phytophthora palmivora, Rhizoctonia solani, and Sclerotinia sclerotiorum and 100% inhibition to Phytophthora cinnamomi with only slight to no inhibition of the other pathogens that were tested. From this work, it is becoming increasingly apparent that each isolate of this endophytic Nodulisporium spp., including the Daldina sp. and Hypoxylon spp. teleomorphs, seems to produce its own unique set of VOCs.

• Journal of Life Science
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• v.17 no.8 s.88
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• pp.1111-1114
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• 2007

The volatile flavor components of buckwheat (Fagopyrum esculentum Moench)-green tea were analyzed and identified. To make tea having good flavor and functional property, parched buckwheat (50%) was mixed with green tea (50%). The extraction of volatile flavor compounds of buckwheat-green tea was accomplished by a simultaneous distillation and extraction method using a Likens and Nickerson's extraction apparatus. The concentrated extract was analyzed and identified by gas chromatography and GC-mass spectrometry. The main volatile flavor components of buckwheat-green tea were compounds that originated from parched buckwheat and the green tea. The former were 15 pyrazines having roasted and nutty aroma and methylbutanals and furfural having sweet-aroma. The latter were nerolidol, linalool, indole, ${\beta}-ionone$ and geraniol etc having flower-like odor in green tea.

• Journal of Life Science
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• v.21 no.2
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• pp.292-299
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• 2011

This study compared volatile flavor profiles of 4 commercial vinegar beverages (Italian vinegar beverage (IVB), Japanese vinegar beverage (JVB), Japanese Yuzu-Ponz (JYP), and Korean white wine vinegar beverage (KWVB)). Flavor components of vinegar beverages (VBs) were determined using SPME/GC/MSD. The profiles of VBs were as follows; IVB (11 acids, 17 esters, 10 alcohols, 8 aldehydes, 3 terpenes, 4 aromatic hydrocarbons, 9 ketones), JVB (7 acids, 8 esters, 9 alcohols, 7 aldehydes, 13 terpenes, 7 aromatic hydrocarbons, 1 ketones, 3 miscellaneous compounds), JYP (3 acids, 12 esters, 8 alcohols, 7 aldehydes, 63 terpenes, 6 aromatic hydrocarbons, 2 ketones, 5 miscellaneous compounds), KWVB (10 acids, 10 esters, 9 alcohols, 8 aldehydes, 2 terpenes, 5 aromatic hydrocarbons, 4 ketones, 2 miscellaneous compounds). IVB and JVB showed similar flavor compositions (acids, ketones and esters in particular), whereas major components in JYP and KWVB were terpenes (79.6%) and acids (81.0%), respectively. Five compounds including 2-phenylethyl acetate (floral, fruity, sweet odor), 2-phenylethanol (floral, rose odor), vitispirane (fruity odor), geranylacetone (fragrant odor) and acetic acid were identified as major components in balsamic vinegar beverages.

• Korean Journal of Food Science and Technology
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• v.28 no.2
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• pp.330-336
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• 1996

Quality characteristics of mash of takju prepared by different raw materials such at nonglutinous rice. glutinous rice, barley and wheat flour were investigated during fermentation. At the beginning stage of fermentation, ethanol content was in the range of $0{\sim}1.2%$ but it was increased to $9.8{\sim}11.6%$ after 16 day of fermentation. takju that was made of nonglutious rice with starter showed higher ethanol content than any other treatment. At the first stage, pH of takju that was made of nonglutinous rice without starter was 6.57 while other sample showed pH $5.04{\sim}5.80.$ There was no significant difference in pH value between treatments after 2 day of fermentation. Total acid was increased rapidly at the first stage of fermentation, and increased slowly after 2 day of fermentation. Takju that was made of nonglutious rice without of fermentation, and increased slowly after 2 day of fermentation. Takju that was made of nonglutious rice without addition starer showed higher total acid content than the other teratments. Total sugar contents were $19.18{\sim}20.23%$ at the beginning of fermentation, and decreased to $5.21{\sim}14.03%$ after 2-4 days of fermentation. Takju that was made of wheat flour showed higher value of total sugar during the fermentation. Reducing sugar contents of takju decreased with fermentation progressing to $0.2{\sim}0.5%$ after 16 day if fermentation. L value decreased during the fermentation. period and that of takju that was made of barley had lowest L value among the treatment. Alcohols, such as n-propanol ($nd{\sim}0.05\;mg/ml$), iso-butanol (0.02), iso-amyl alcohol ($nd{\sim}0.13$), n-hexanol ($nd{\sim}0.17$), n-heptanol ($nd{\sim}0.09$), and phenylethanol ($nd{\sim}0.02$) were detected. There were no alcohols detected at the beginning of fermentation, but their contents were increased during fermentation.

• Korean Journal of Food Science and Technology
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• v.23 no.1
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• pp.98-101
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• 1991

To investigate the aroma difference of commercial Korean green tea caused by manufacturing process and harvesting time, analysis of aroma concentrates of steamed green teas(1st tea, 2nd tea) and parched green teas(1st tea, 2nd tea) was accomplished. Steamed green tea, which had a briskness, greenish odor and sweet-floral odor, contained large amounts of terpene alcohols such as linalool, nerolidol, ketones such as cis-jasmone, 2,6,6-trimethyl-2-hydroxycyclohexanone and indole, Parched green tea, which had a slightly greenish odor and floral, roast odor, contained large amounts of terpene alcohols such as linalool, geraniol, aromatic alcohols such as benzylalcohol, phenylethanol and phenol, indole. Almost same tendency of odor component change of 1st tea and 2nd tea differed to harvesting time being observed in steamed tea and parched tea. In 2nd tea of both samples, aliphatic alcohols such as 1-penten-3-ol, cis-2-penten-1-al and two 2, 4-heptadienal(cis, trans and trans, trans) increased remarkably. It seems that these four components effects on the grade of the odor.

• Journal of Microbiology and Biotechnology
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• v.29 no.3
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• pp.373-381
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• 2019

Site-directed mutagenesis was employed to generate five different triple point mutations in the double mutant (C295A/I86A) of Thermoanaerobacter ethanolicus alcohol dehydrogenase (TeSADH) by computer-aided modeling with the aim of widening the small alkyl-binding pocket. TeSADH engineering enables the enzyme to accept sterically hindered substrates that could not be accepted by the wild-type enzyme. The underline in the mutations highlights the additional point mutation on the double mutant TeSADH introduced in this work. The catalytic efficiency ($k_{cat}/K_M$) of the ${\underline{M151A}}$/C295A/I86A triple TeSADH mutant for acetophenone increased about 4.8-fold higher than that of the double mutant. A 2.4-fold increase in conversion of 3'-methylacetophenone to (R)-1-(3-methylphenyl)-ethanol with a yield of 87% was obtained by using ${\underline{V115A}}$/C295A/I86A mutant in asymmetric reduction. The ${\underline{A85G}}$/C295A/I86A mutant also produced (R)-1-(3-methylphenyl)-ethanol (1.7-fold) from 3'-methylacetophenone and (R)-1-(3-methoxyphenyl)-ethanol (1.2-fold) from 3'-methoxyacetophenone, with improved yield. In terms of thermal stability, the ${\underline{M151A}}$/C295A/I86A and ${\underline{V115A}}$/C295A/I86A mutants significantly increased ${\Delta}T_{1/2}$ by $+6.8^{\circ}C$ and $+2.4^{\circ}C$, respectively, with thermal deactivation constant ($k_d$) close to the wild-type enzyme. The ${\underline{M151A}}$/C295A/I86A mutant reacts optimally at $70^{\circ}C$ with almost 4 times more residual activity than the wild type. Considering broad substrate tolerance and thermal stability together, it would be promising to produce (R)-1-(3-methylphenyl)-ethanol from 3'-methylacetophenone by ${\underline{V115A}}$/C295A/I86A, and (R)-1-phenylethanol from acetophenone by ${\underline{M151A}}$/C295A/I86A mutant, in large-scale bioreduction processes.

• Journal of KIISE:Software and Applications
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• v.33 no.2
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• pp.143-153
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• 2006

Microarray which enables us to obtain hundreds and thousands of expression of gene or genotype at once is an epoch-making technology in comparative analysis of genes. First of all, we have to measure the intensity of each gene in an microarray image from the experiment to gain the expression level of each gene. But it is difficult to analyze the microarray image in manual because it has a lot of genes. Meta-gridding method and various auto-gridding methods have been proposed for this, but thew still have some problems. For example, meta-gridding requires manual-work due to some variations in spite of experiment in same microarray, and auto-gridding nay not carried out fully or correctly when an image has a lot of noises or is lowly expressed. In this article, we propose Hierarchical Grid Alignment algorithm for new methodology combining meta-gridding method with auto-gridding method. In our methodology, we necd a meta-grid as an input, and then align it with the microarray image automatically. Experimental results show that the proposed method serves more robust and reliable gridding result than the previous methods. It is also possible for user to do more reliable batch analysis by using our algorithm.