• Food Science of Animal Resources
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• v.29 no.5
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• pp.640-646
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• 2009

Lactic acid bacteria (LAB) are typical probiotic microbes that are used in various industries including fermented foods, feed additives, and pharmaceuticals. The purpose of this study was to compare the ability of isoflavone biotransformation and antioxidative activity of 17 LAB. Six strains including the Lactobacillus species exhibited a 100% hydrolysis rate for daidzein during fermentation. The content of total genistein in soymilk fermented with these strains was $872-943\;{\mu}g/g$. The DPPH (1, 1-diphenyl-2-picrylhydrazyl) radical scavenging ability of the LAB was widely variable and ranged from 23-78%. A selected strain was isolated from kimchi and the strain was identified as Lactobacillus plantarum ssp. through the API carbohydrate fermentation pattern and 16S rDNA profile. The strain exhibited excellent acid tolerance in an artificial gastric solution. L. plantarum YS712 showed high $\beta$-glucosidase activity in fermentation. The concentration of genistein and daidzein in soymilk fermented with L. plantarum YS712 increased from 3.64 to $917.3\;{\mu}g/g$ and from 58.18 to $1062.17\;{\mu}g/g$, respectively. These results demonstrate the potential of L. plantarum YS712 as a probiotic culture that can be utilized in the manufacturing of fermentation foods and dietary supplements.

• Korean Journal of Food Science and Technology
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• v.26 no.1
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• pp.44-50
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• 1994

In order to develop an effective extraction method of sea mustard, five different methods of boiling in 0.5% $Na_{2}EDTA(A)$, in 0.1 N HCI(B), in 0.5% $Na_{2}EDTA$ and 0.1 N HCI(C) and hydrolysis with two different polysaccharides-hydrolyzing enzymes of Celluclast(method D) and Ultrazyme(method E) prior to boiling in 0.5% $Na_{2}EDTA$ and 0.1 N HCI were studied. The highest yields of solids(63.14%) and protein(26.39%) from the extract were obtained by method D. The concentration of amino-N was significantly improved by method C(870 ppm) followed by method D(770 ppm), B(570 ppm) and A(480 ppm) compared to the control(270 ppm). Total free amino acids, mainly alanine, glutamic, and aspartic acids, were greatly increased by methods of A(8.88 mg%), D(4.14 mg%) and E(4.18 mg%) which were $2.5{\sim}5.1$ times higher than those in control(1.71 mg%). The sensory characteristics showed that extract D was significantly low in intensity of fishy odor and high in seaweed taste. Therefore, method D was suggested as the effective extraction method.

• Microbiology and Biotechnology Letters
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• v.44 no.3
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• pp.317-323
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• 2016

An isoflavone glucosidase that catalyzes the hydrolysis of isoflavone glucosides into glucose and corresponding aglycones was purified from Candida fermentati SI. The N-terminal sequence was determined to be GLNCDYCN. We designed degenerate primers on the basis of these amino acid sequences and successfully cloned the full structural gene sequence of the isoflavone glucosidase using inverse PCR. The exo-β-(1,3)-glucanase gene consists of 1227 base-pair nucleotides, encoding a 408-amino-acid sequence that shares 41–96% amino acid homology with other yeast exo-β-(1,3)-glucanases belonging to glycoside hydrolase family 5. The recombinant exo-β-(1,3)-glucanase was expressed in Pichia pastoris X-33, using a pPICZA vector system, and further characterized. The molecular mass of the purified exo-β-(1,3)-glucanase was estimated by SDS-PAGE to be 47 kDa. The optimal pH and temperature were pH 4.5 and 40℃, respectively. The K_m values of the purified exo-β-(1,3)-glucanase for daidzin and genistin were 0.12 mM and 0.14 mM, respectively. The V_max values of the purified isoflavone glucosidase were 945.03 U/mg for daidzin and 835.92 U/mg and for genistin.

• Applied Biological Chemistry
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• v.19 no.1
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• pp.1-23
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• 1976

The female moths of Lepidoptera comprising over 1,000,000 described species possess long-chain unsaturated alcohols or esters as the typical structure of potential sex attractants. In this experiment, various stereoisomers of $C_{16}-unsaturated$ acetates were synthesized for potential sex attractants; e.g., $CH_3(CH_2)_mCH=CH(CH_2)_nOR$ (m=0-12, n=1-13, R=H and $-COCH_3$). Seventeen acetates were spectrometrically examined so that the data would provide a ready catalog of gas chromatography and mass spectrometric data for comparison with natural insect sex attractants. Exclusively cis and trans isomers were obtained by the catalytic and chemical reduction methods, respectively. Commercially available $CH_3(CH_2)_mBr,\;CH_3(CH_2)_mC{\equiv}CH,\;HC{\equiv}C(CH_2)_nOH\;and\;HO(CH_2)_n\;OH$ were used for the synthetic starting material. 1-Alkynes, $CH_3(CH_2)_m\;C{\equiv}CH$ exceeding nine methylene groups did not condense with alkyl dihalides. The yield of coupling products was gradually decreased with increasing the molecular weight of diols. In the coupling reaction of $BrCH_2CH_2$ OTHP with acetylene gas, the tetrahydropyranyl ether of bromohydrin produced undesirable elimination product. In this experiment, it seems that p-toluenesulfonic acid is greatly favoured hydrolyzing agent over dilute sulfuric acid in the hydrolysis of the tetrahydropyranyl ether of long-chain alkynols.

• Journal of Life Science
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• v.14 no.5
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• pp.752-760
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• 2004

The function of the [4Fe-4S] cluster containing iron (Fe-) protein in nitrogenase catalysis is to serve as the nucleotide-dependent electron donor to the MoFe protein which contains the sites for substrate binding and reduction. The ability of the Fe protein to function in this manner is dependent on its ability to adopt the appropriate conformation for productive interaction with the MoFe protein and on its ability to change redox potentials to provide the driving force required for electron transfer. The MgADP-bound (or off) conformational state of the nitrogenase Fe protein structure described reveals mechanisms for long-range communication from the nucleotide-binding sites to control affinity of association with the MoFe protein component. Two pathways, termed switches I and II, appear to be integral to this nucleotide signal transduction mechanism. In addition, the structure of the MgADP bound Fe protein provides the basis for the changes in the biophysical properties of the [4Fe-4S] observed when Fe protein binds nucleotides. The structures of the nitrogenase Fe protein with defined amino acid substitutions in the nucleotide dependent signal transduction pathways of the Switch I and Switch II have been determined by X-ray diffraction methods. These two pathways have been also implicated by site directed mutagenesis studies, structural analysis and analogies to other proteins that utilize similar nucleotide dependent signal transduction pathways. We have examined the validity of the assignment of these pathways in linking the signals generated by MgATP binding and hydrolysis to macromolecular complex formation and intermolecular electron transfer. The results provide a structural basis for the observed biophysical and biochemical properties of the Fe protein variants and interactions within the nitrogenase Fe protein-MoFe protein complex.

• Applied Chemistry for Engineering
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• v.3 no.2
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• pp.266-272
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• 1992

Azacrownoalkyl phenylphosphinic acids were synthesized and their competitive solvent extraction characteristics from water to chloroform layer were investigated. Phosphinic acids were synthesized in good yields by one step reaction of phenylphosphinate, aldehyde, and monoazacrown ether and then basic hydrolysis of the resulting phosphinate dsters. These complexing agents revealed a wide effective pH range in extraction of alkali metal ions from water to the organic phase and total metal ion loading at pH 11 was about 75%. The selectivity of the cation extraction was determined mainly by the cavity size of the azacrown ethers, showing $Na^+$ >> $K^+$ > $Rb^+$ > $Li^+$ > $Cs^+$ for the alkyl phenylphosphinic acid ${\underline{2}}$, containing monoaza-15-crown-5 and $K^+$ >> $Rb^+$ > $Na^+$ > $Cs^+$ > $Li^+$ for the alkyl phenylphosphinic acid, ${\underline{3}}$, containing monoaza-18-crown-6 moiety. Applicable pH range of these azacrown ether phosphinic acids in solvent extraction of alkali metal cations was wider than a crownether carboxylic acid with similar selectivity, showing considerable amount of metal ion loading in slightly acidic or neutral media.

• Parasites, Hosts and Diseases
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• v.27 no.3
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• pp.161-170
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• 1989

The proteases of Toxoplasma gcndii were purified partially and characterisrd for some biochemical properties including various chromatographic patterns, major catalytic classes, and conditions to promote the activity of these enzymes. When Toxoplasma extract was incubated with 3H-casein at various pH, peak hydrolysis of casein was observed at pH 6.0 and at pH 8.5. Proteasfs working at pH 6.0 and at pH 8.5 were purified partially by conventional methods of chromatographies of DE52 anion rxchange, Sephadex G-200 gel permeation, and hydroxylapatite chromatography. Partially purified enzymes were tested by site-specific inhibitors and promotorf. The protease working at pH 6.0 was inactivated by iodoacetamide with LDso of 10-5 M and promoted by dithiothreitol, while the protease working at pH 8.5 was inhibited by phenylmethylsulfonyl fluoride with LD50 of 10-5 M and was Promoted by ATP (excess ATP beyond 2 mM inhibited the activity reversely). The protease of pH 8.5 had the activity of ATPase which might exert the energy to its action. Therefore the former was referred to as a cysteinyl acid protease and the latter, ATP-dependent neutral serine protease.

• Korean Journal of Microbiology
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• v.52 no.3
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• pp.336-343
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• 2016

A mannanase gene was cloned into Escherichia coli from Cellulosimicrobium sp. YB-43, which had been found to produce two kinds of mannanase, and sequenced completely. This mannanase gene, designated manB, consisted of 1,284 nucleotides encoding a polypeptide of 427 amino acid residues. Based on the deduced amino acid sequence, the ManB was identified to be a modular enzyme including two carbohydrate binding domains besides the catalytic domain, which was highly homologous to mannanases belonging to the glycosyl hydrolase family 5. The N-terminal amino acid sequence of ManB, purified from a cell-free extract of the recombinant E. coli carrying a Cellulosimicrobium sp. YB-43 manB gene, has been determined as QGASAASDG, which was correctly corresponding to signal peptide predicted by SignalP4.1 server for Gram-negative bacteria. The purified ManB had a pH optimum for its activity at pH 6.5~7.0 and a temperature optimum at $55^{\circ}C$. The enzyme was active on locust bean gum (LBG), konjac and guar gum, while it did not exhibit activity towards carboxymethylcellulose, xylan, starch, and para-nitrophenyl-${\beta}$-mannopyranoside. The activity of enzyme was inhibited very slightly by $Mg^{2+}$, $K^+$, and $Na^+$, and significantly inhibited by $Cu^{2+}$, $Zn^{2+}$, $Mn^{2+}$, and SDS. The enzyme could hydrolyze mannooligosaccharides larger than mannobiose, which was the most predominant product resulting from the ManB hydrolysis for mannooligosaccharides and LBG.

• Korean Journal of Environmental Agriculture
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• v.29 no.4
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• pp.348-353
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• 2010

The current study investigated the fate of organic matter in piggery slurry under two different store systems(closed store system and open store system) in association with different temperature. Thirty days after storing in both systems at $20^{\circ}C$, it was observed that the content of organic matter remained in piggery slurry with closed store system was twice more than that with open store system implying more efficient degradation of organic matter with open store system. Temperature also influenced on the organic matter degradation in piggery slurry as shown decline in TS and VS contents as the temperature increased. With store at $35^{\circ}C$, 29% of initial organic matter was reduced while there was only 23% reduction of organic matter at $20^{\circ}C$. There was no difference in the type of organic fatty acids(VFAs) produced under the range of temperature(20, $35^{\circ}C$) simulating summer condition. Increases in organic fatty acids contents with hydrolysis and acid producing microbial was observed from 15 days after initiating store of the piggery slurry and the total organic acid amount produced 30 days after store was $2,829\;mg{\cdot}COD/L$ and $9,123\;mg{\cdot}COD/L$ at $20^{\circ}C$ and $35^{\circ}C$, respectively. These corresponded to 5.4% and 17.4% of the initial organic matter contents in piggery slurry, respectively.

• Applied Chemistry for Engineering
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• v.25 no.4
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• pp.392-395
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• 2014

(2S,3S,4S)-3,4-Dihydroxyglutamic acid (DHGA), a biologically active ${\alpha},{\beta}$-dihydroxy-${\gamma}$-amino acid, was efficiently synthesized from a readily available D-serine derivative in 30% overall yield over 11 steps. The key stereoselective $OsO_4$-catalyzed dihydroxylation reaction controlled by an N-diphenylmethylene group on the amino group of ${\gamma}$-amino-${\alpha},{\beta}$-unsaturated (Z)-ester successfully introduced the diol moiety of the intermediate 5a in 86% with more than 10 : 1 diastereomeric ration. Then it was in turn successfully converted to the desired target compound, (2S,3S,4S)-3,4-DHGA, via simple oxidation and hydrolysis in a highly stereoselective manner and a higher yield than the previous syntheses. This result strongly supports that our synthetic methodology of stereoselective $OsO_4$-catalyzed dihydroxylation should be useful in stereoselctive synthesis of various bioactive compounds with an amino diol moiety.