Bioconversion of ginsenosides Rb₁, Rb₂, Rc and Rd by novel β-glucosidase hydrolyzing outer 3-O glycoside from Sphingomonas sp. 2F2: Cloning, expression, and enzyme characterization

Wang, L.,Liu, Q.M.,Sung, B.H.,An, D.S.,Lee, H.G.,Kim, S.G.,Kim, S.C.,Lee, S.T.,Im, W.T. Elsevier Science Publishers 2011 Journal of biotechnology Vol.156 No.2

A new β-glucosidase gene (bglSp) was cloned from the ginsenoside converting Sphingomonas sp. strain 2F2 isolated from the ginseng cultivating filed. The bglSp consisted of 1344bp (447 amino acid residues) with a predicted molecular mass of 49,399Da. A BLAST search using the bglSp sequence revealed significant homology to that of glycoside hydrolase superfamily 1. This enzyme was overexpressed in Escherichia coli BL21 (DE3) using a pET21-MBP (TEV) vector system. Overexpressed recombinant enzymes which could convert the ginsenosides Rb<SUB>1</SUB>, Rb<SUB>2</SUB>, Rc and Rd to the more pharmacological active rare ginsenosides gypenoside XVII, ginsenoside C-O, ginsenoside C-Mc<SUB>1</SUB> and ginsenoside F<SUB>2</SUB>, respectively, were purified by two steps with Amylose-affinity and DEAE-Cellulose chromatography and characterized. The kinetic parameters for β-glucosidase showed the apparent K<SUB>m</SUB> and V<SUB>max</SUB> values of 2.9+/-0.3mM and 515.4+/-38.3μmolmin<SUP>-1</SUP>mg of protein<SUP>-1</SUP> against p-nitrophenyl-β-d-glucopyranoside. The enzyme could hydrolyze the outer C3 glucose moieties of ginsenosides Rb<SUB>1</SUB>, Rb<SUB>2</SUB>, Rc and Rd into the rare ginsenosides Gyp XVII, C-O, C-Mc<SUB>1</SUB> and F<SUB>2</SUB> quickly at optimal conditions of pH 5.0 and 37<SUP>o</SUP>C. A little ginsenoside F<SUB>2</SUB> production from ginsenosides Gyp XVII, C-O, and C-Mc<SUB>1</SUB> was observed for the lengthy enzyme reaction caused by the side ability of the enzyme.

Photoluminescent properties and site occupation preference in Bi³⁺, Eu³⁺ doped CaY₄(SiO₄)₃O phosphor

Wang, L.,Moon, B.K.,Choi, B.C.,Kim, J.H.,Shi, J.,Jeong, J.H. Ceramurgica ; Elsevier Science Ltd 2016 CERAMICS INTERNATIONAL Vol.42 No.11

Bi<SUP>3+</SUP>, Eu<SUP>3+</SUP> doped CaY<SUB>4</SUB>(SiO<SUB>4</SUB>)<SUB>3</SUB>O phosphors were synthesized through high temperature solid state reaction. Their photoluminescent properties were investigated and site occupation preference of Bi<SUP>3+</SUP> in cationic sites was analyzed. The structure of CaY<SUB>4</SUB>(SiO<SUB>4</SUB>)<SUB>3</SUB>O is characterized by three non-equivalent cationic sites with different coordination and cation-oxygen distances. By means of dielectric theory of the chemical bond for complex crystals, several kinds of chemical bond parameters like fractional covalence of CaY<SUB>4</SUB>(SiO<SUB>4</SUB>)<SUB>3</SUB>O were calculated and integrated to yield environmental factor h<SUB>e</SUB>. According to quantitative equations between the transition energy of Bi<SUP>3+</SUP> and environmental factor h<SUB>e</SUB>, the excitation bands at 308 and 226nm were assigned to <SUP>1</SUP>S<SUB>0</SUB>→<SUP>3</SUP>P<SUB>1</SUB> transition of Bi<SUP>3+</SUP> in Y(6h) and Y(4f) site, respectively. Another excitation band centered at 210nm should be the overlap of Bi<SUP>3+</SUP>A-band in Ca site and C-band in Y(6h) site. Optical band gap of pure CYSO was calculated using Kubelka-Munk method from diffuse reflectance spectra. Red emission can be realized in CaY<SUB>4</SUB>(SiO<SUB>4</SUB>)<SUB>3</SUB>O:Bi<SUP>3+</SUP>, Eu<SUP>3+</SUP> under UV light excitation because of efficient energy transfer from Bi<SUP>3+</SUP> to Eu<SUP>3+</SUP> and decay behaviors of Bi<SUP>3+</SUP> and Eu<SUP>3+</SUP> emission were investigated. Without optimization, the internal quantum efficiency of CYSO:2%Bi<SUP>3+</SUP>, 7%Eu<SUP>3+</SUP> at 310 and 393nm excitations were 31.563%, 74.252%, respectively.

Dielectric and piezoelectric properties of Li-substituted lead-free (Bi_0.5Na_0.5)TiO₃@?(Bi_0.5K_0.5)TiO₃@?BaTiO₃ ceramics

Wang, L.,Song, T.K.,Lee, S.C.,Cho, J.H.,Sung, Y.S.,Kim, M.H.,Choi, K.S. Elsevier 2010 CURRENT APPLIED PHYSICS Vol.10 No.4

Lead-free 0.79(Bi<SUB>0.5</SUB>Na<SUB>0.5</SUB>)TiO<SUB>3</SUB>-0.14[Bi<SUB>0.5</SUB>(K<SUB>0.5-x</SUB>Li<SUB>x</SUB>)]TiO<SUB>3</SUB>-0.07BaTiO<SUB>3</SUB> (BNBK79+xLi, x=0.0, 0.1, 0.2, 0.25, 0.3, and 0.4) ceramics were prepared by conventional solid state reaction process. The crystalline structures and surface morphologies are investigated by X-ray diffraction method and scanning electron microscopy. Dielectric and piezoelectric properties were measured. With increasing of lithium substitution, the Curie temperatures of BNBK79+xLi ceramics increase, but the maximum value of the dielectric constant decreases. And a relatively large remnant polarization of 17.6μC/cm<SUP>2</SUP> and 157pC/N of d<SUB>33</SUB> has been obtained when x=0.3.

Electronic properties of graphene on the C-decorated Si(111) surface:An ab initio study

J. Liu,C.Y. He,W. Wang,N. Jiao,C.X. Zhang,L.Z. Sun 한국물리학회 2013 Current Applied Physics Vol.13 No.7

First principles calculations based on the density functional theory are performed to study electronic structures of graphene adsorbed on clean or C-decorated Si(111) surface. Two types of surface reconstructions,2 x 2 and ffiffiffi 3p x 3p , are considered to be decorated by carbon atoms with different concentrations. We find that graphene adsorbed on ideal clean Si(111) surface tends to induce a 2 x 1reconstruction, and its electronic dispersion characteristics are preserved. Moreover, the decoration of carbon atoms on the Si(111) surface can effectively passivate the Si dangling bonds on the surface. Such decoration effects make the carbon deco

Effect of Annealing Temperature on Binary TiO2:SiO2 Nanocrystalline Thin Films

F. Mei,C. Liu,J. B. Wang,L. Zhou,W. K. Zhao,Y. L. Fang,Y. Y. Ren 한국물리학회 2006 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.48 No.6

Binary TiO2:SiO2 nanocrystalline thin films were prepared using liquid phase deposition at 35 C and annealed in air at temperatures ranging from 100 C to 500 C. The microstructural and the optical properties of the thin films were characterized by using an ultraviolet-visible spectrophotometer, a Fourier transform infrared spectrophotometer, a scanning electron microscope, and a transmission electron microscope. The photocatalytic performance of the thin films was evaluated by using photocatalytic degradation of methylene blue. The results showed that most TiO2 nanocrystallites were uniformly dispersed onto an amorphous SiO2 matrix and that nanopores had been formed on top of the TiO2 nanoparticles, resulting in an improved photocatalytic efficiency due to an increase number of effective adsorption sites. As we increased the annealing temperature, the small crystallites progressively aggregated into larger clusters, reducing the specific surface area of the TiO2 nanocrystallites. Moreover, SiO2 nanopowders moved towards the surface and covered the TiO2, resulting in a decreased photocatalytic activity.e

Magnetic and Magneto-Optical Properties of Co-Sputtering FePt Films

J. Gao,B. Ma,C.L. Zha,Q.Y. Jin,S.Y. Wang,Z.Z. Zhang 한국물리학회 2006 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.49 No.5I

FePt thin .lms have been prepared at dierent substrate temperatures by DC magnetron co-sputtering. The .lms change from a disordered fcc structure to a L10 fct structure with temperature. The magnetic and the magneto-optical properties of those FePt .lms have been studied. The dependence of spectral changes on the formation of a chemically-ordered L10structure is observed in the polar magneto-optical Kerr rotation. In the spectra, the ultraviolet peak located in the high-energy range (4.0 { 4.5 eV), which is related to electronic transitions on Pt atomic sites, is observed for all samples. On the contrary, the peak related to transitions on Fe atomic sites, which is located in the low-energy range (1.5 { 2.0 eV), is only observed for highly chemically-ordered samples. Compared with the spectra for the L10 structure of FePt .lms pre- pared by using molecular beam epitaxy, the infrared peak related to Fe sites is shifted to low energy.

Effect of night light regimen on growth performance, antioxidant status and health of broiler chickens from 1 to 21 days of age

R.X. Zhao,C.H. Cai,P. Wang,L. Zheng,J.S. Wang,K.X. Li,W. Liu,X.Y. Guo,X. A. Zhan,K.Y. Wang 아세아·태평양축산학회 2019 Animal Bioscience Vol.32 No.6

Objective: The study was conducted to evaluate the effects of night light regimen on growth performance, antioxidant status and health of Lingnan Yellow broiler chickens from 1 to 21 days of age. Methods: A completely randomized factorial design involved 2 photoperiods (constant lighting [CL], 24 L:0 D and intermittent lighting [INL], 17 L:3 D:1 L:3 D)×2 light intensities (10 lx and 30 lx). A total of one thousand six hundred and eighty 1-d-old Lingnan Yellow broiler chicks were randomly divided into 4 treatments with 6 replicates (70 birds per replicate). The experiment lasted for 21 d. Results: Photoperiods and light intensities had no effect on average daily gain, feed conversion ratio, and mortality of the broiler chickens (p>0.05). The INL had a significant effect on average daily feed intake (p<0.05) of broiler chickens compared with CL. Photoperiod and light intensity had an interactive effect on melatonin (MT) concentration (p<0.05). At CL, reducing light intensity increased MT concentration; INL birds had higher MT but MT concentration was not affected by light intensity. There was an interactive effect on glutathione peroxidase (GPx) and catalase (CAT) in serum and total antioxidant capability (T-AOC) in liver between photoperiod and light intensity. With the decrease of light intensity, the activities of GPx and CAT in serum and T-AOC in liver increased in CL group (p<0.05). Broiler chickens reared under INL had better antioxidant status and 10 lx treatments had higher activities of CAT in serum than 30 lx (p<0.05). Different photoperiods and light intensities had no effect on malondialdehyde. There was an interaction between photoperiod and light intensity on serum creatine kinase (CK) concentration (p<0.05). At CL, the elevated light intensity resulted in an increase in CK content; INL birds had lower CK concentration especially in low light intensity group. Besides, INL and low light intensity significantly reduced the concentration of serum corticosterone and heat shock protein 70 (p<0.05). Serum immunoglobulin M contents were increased in broiler chickens reared under the INL compared with CL group (p<0.05). Conclusion: Results above suggest that the night light regimen of INL and 10 lx could be beneficial to the broiler chickens from 1 to 21 days of age due to the better health status and electricity savings.

Fabricating Ultrathin Plate-Like WC Grains in WC–8Co Hardmetals by Increasing Discharge Intensity During Plasma-Assisted Ball Milling

M. Q. Zeng,J. L. Tu,M. Zhu,W. Wang,J. W. Liu,Z. C. Lu 대한금속·재료학회 2020 METALS AND MATERIALS International Vol.26 No.9

The effects of plasma discharge intensity on the microstructure evolution of ball-milled tungsten (W)–carbon (C)–cobalt (Co)mixtures and the formation mechanism of ultrathin plate-like tungsten carbide (WC) grains prepared by ball milling with andwithout plasma discharge were investigated. It was found that increasing the plasma discharge intensity during ball millingobviously promoted the formation of a thin flake-like W phase because of the electroplasticity effect and simultaneouslylowered the carburization temperature between W and C. A combination of high hardness and transverse rupture strength of92.9 HRA and 3659 MPa, respectively, was obtained for the WC–8Co alloy fabricated by plasma milling at a gas pressure of5 × 103 Pa with a dielectric barrier discharge layer thickness of 3 mm. These properties were mainly attributed to the markedlylowered activation energy of the WC phase and generation of highly oriented ultrathin plate-like WC grains by plasma milling. The combination of the flake-like structure of the plasma-milled W aggregate and high specific interfacial area and shortdiffusion distance of W/C were readily inherited by the ultrathin plate-like WC grains in the sintered WC–Co hardmetals.

An Innate Bactericidal Oleic Acid Effective Against Skin Infection of Methicillin-Resistant Staphylococcus aureus: A Therapy Concordant with Evolutionary Medicine

( Chao Hsuan Chen ),( Yan Han Wang ),( Teruaki Nakatsuji ),( Yu Tsueng Liu ),( Christos C. Zouboulis ),( Richard L. Gallo ),( Liangfang Zhang ),( Ming Fa Hsieh ),( Chun Ming Huang ) 한국미생물 · 생명공학회 2011 Journal of microbiology and biotechnology Vol.21 No.4

Free fatty acids (FFAs) are known to have bacteriocidal activity and are important components of the innateimmune system. Many FFAs are naturally present in human and animal skin, breast milk, and in the bloodstream. Here, the therapeutic potential of FFAs against methicillin-resistant Staphylococcus aureus (MRSA) is demonstrated in cultures and in mice. Among a series of FFAs, only oleic acid (OA) (C18:1, cis-9) can effectively eliminate Staphylococcus aureus (S. aureus) through cell wall disruption. Lauric acid (LA, C12:0) and palmitic acid (PA, C16:0) do not have this ability. OA can inhibit growth of a number of Gram-positive bacteria, including hospital and community-associated MRSA at a dose that did not show any toxicity to human sebocytes. The bacteriocidal activities of FFAs were also demonstrated in vivo through injection of OA into mouse skin lesions previously infected with a strain of MRSA. In conclusion, our results suggest a promising therapeutic approach against MRSA through boosting the bacteriocidal activities of native FFAs, which may have been co-evolved during the interactions between microbes and their hosts.

The Expression of Genes Related to Egg Production in the Liver of Taiwan Country Chickens

Ding, S.T.,Ko, Y.H.,Ou, B.R.,Wang, P.H.,Chen, C.L.,Huang, M.C.,Lee, Y.P.,Lin, E.C.,Chen, C.F.,Lin, H.W.,Cheng, Winston Teng Kuei Asian Australasian Association of Animal Productio 2008 Animal Bioscience Vol.21 No.1

The purpose of this study was to detect expression of genes related to egg production in Taiwan Country chickens by suppression subtractive hybridization. Liver samples of mRNA extraction from two Taiwan Country chicken strains (L2 and B), originated from the same population but with very distinct egg production rates after long-term selection for egg and meat production respectively. Two-way subtraction was performed. The hepatic cDNA from the low egg production chickens (B) was subtracted from the hepatic cDNA from the high egg production strain (L2). The reversed subtraction (L2 from B) was also performed. The resulting differentially expressed gene fragments were cloned and sequenced. We sequenced 288 clones from the forward subtraction and 96 clones from the reverse subtraction. These genes were subjected to further screening to confirm the differential expression between the two genetic breeds of chickens. The apolipoprotein B (apoB) was expressed to a greater extent in the liver of the L2 than in the B line chickens. The 5-aminoimidazole- 4-carboxamide ribonucleotide formyltransferase/IMP cyclohydrolase (PURH) was expressed to a greater extent in the liver of the B than in the L2 strain chickens. We demonstrated that both apoB and PURH were more highly expressed in the liver than that in other tissues (muscle, ovary, and oviduct) in laying Taiwan Country chickens. Taken together, these data suggest that after the selection for egg production, expression of apoB and PURH genes were also changed. Whether the changed expression of these genes is directly related to egg production is not known, but these two genes may be useful markers for egg laying performance in Taiwan Country chickens.