• 제목/요약/키워드: biochemical characterization

검색결과 682건 처리시간 0.041초

화학환원법을 이용한 Ag-Pd 합금 나노분말의 합성 (Synthesis of Ag-Pd Alloy Nanoparticles by Chemical Reduction Method)

  • 서원식;김윤도;정일엽;이호석;송기창
    • 한국세라믹학회지
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    • 제43권4호
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    • pp.224-229
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    • 2006
  • Ag-Pd alloy nanoparticles were prepared by a chemical reduction method using hydrazine $(N_2H_4)$ as a reductant in $AgNO_3\;and\;Pd(NO_3)_2$ aqueous solutions. Characterization of these particles by X-ray powder diffraction revealed a bimetallic and crystalline silver-palladium alloy. The average size of the particles was influenced not by the reductant $(N_2H_4)$ concentration, but the concentration of the starting materials $(AgNO_3\;and\;Pd(NO_3)_2)$.

Characterization of the Replication Region of the Enterococcus faecalis Plasmid p703/5

  • Song, Joon-Seok;Park, Jin-Hwan;Kim, Chan-Wha;Kim, Young-Woo;Lim, Wang-Jin;Kim, Ick-Young;Chang, Hyo-Ihl
    • Journal of Microbiology and Biotechnology
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    • 제9권1호
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    • pp.91-97
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    • 1999
  • In this work, a 1.9-kb region of enterococcal plasmid p703/5 was isolated and the nucleotide sequence analysis of the region was performed. One major open reading frame (ORF) was identified encoding a polypeptide of 28 kDa. Database comparisons suggested that the protein showed some homology with other bacterial RepA proteins. Upstream of the ORF, a potential dnaA box, AT-rich region and 22-bp tandemly repeated sequences (DNA iterons), a feature typical for many replication ori sites, were recognized. Deletion analysis using Exonuclease III and several restriction enzymes indicated that the three elements and the gene product from the ORF were essential for replication and that the minimum unit of DNA required for replication resided on the 1.2-kb AvaII subfragment. Thus, this gene product was referred to as RepA.

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BIOCHEMICAL CHARACTERIZATION OF EMBRYONIC CHICK CALVARIAL CELLS

  • Yu, Jae-Hyung;Kim, Jung-Kun;Cha, Kyung-Suk
    • 대한치과교정학회지
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    • 제25권6호
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    • pp.697-704
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    • 1995
  • Chicken calvarial bone is known to contain various cell types, but their exact composition is unknown. By characterizing the chicken calvarial bone biochemically, it can be used to study biochemical, histochemical actions of bone cells in general. Calvaria of 18-day-old white leg horn embryo was aseptically dissected and bone cell populations were isolated by sequential enzymatic digestion. Histochemical study for osteoclast-like bone cell. population was performed with tartrate resistant acid phosphatase(TRAP) stain and for osteoblast-like bone cell population, alkaline phosphatase(ALP) stain was performed. Biochemical study for osteoblast-like bone cell population was performed using alkaline phosphatase(ALP) assay. Following conclusions were obtained from this study. 1. TRAP positive multi and mononuclear cells were mostly observed in group I and II, indicating that osteoclast-like bone cell population is mostly found in these groups. 2. All the cultured groups showed almost equal ALP activities and were positive for ALP stain, indicating that osteoblast-like bone cell population is evenly dispersed in all culture groups. 3. Experimental group treated with $1,25(OH)_{2}D_3$ showed increase in ALP activity in contrast to the control group, confirming previous studies that $1,25(OH)_{2}D_3$ increases ALP activities in in vitro bone cultures. 4. Results from von Kossa's stain indicated that in vitro bone formation had occured after 3 weeks of culture with beta-glycero phosphate.

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Isolation and Characterization of a Novel Lactic Acid Bacterium for the Production of Lactic Acid

  • Wee, Young-Jung;Yun, Jong-Sun;Park, Don-Hee;Ryu, Hwa-Won
    • Biotechnology and Bioprocess Engineering:BBE
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    • 제9권4호
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    • pp.303-308
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    • 2004
  • We isolated a novel lactic acid bacterium from a Korean traditional fermented food, soybean paste. The newly isolated strain, dubbed RKY2, grew well on glucose, sucrose, galactose, and fructose, but it could not utilize xylose, starch, or glycerol. When the partially amplified 16S rDNA sequence (772 bp) of the strain RKY2 was compared with 10 reference strains, it was found to be most similar to Lactobacillus pentosus JCM $1588^T$, with 99.74% similarity. There-fore, the strain RKY2 was renamed Lactobacillus sp. RKY2, which has been deposited in the Korean Collection for Type Cultures as KCTC 10353BP. Lactobacillus sp. RKY2 was found to be a homofermentative lactic acid bacterium, because its end-product from glucose metabolism was found to be mainly lactic acid. It could produce more than 90 g/L of lactic acid from MRS medium supplemented with 100 g/L of glucose, with 5.2 g $L^-1$ $h^-1$ of productivity and 0.95 g/g of lactic acid yield.

Biochemical Characterization of Protease Produced by Cordyceps nutans

  • Kim, Seon Ah;Kim, Mi-Kyung
    • 대한임상검사과학회지
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    • 제44권4호
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    • pp.216-221
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    • 2012
  • The fruiting body of Cordyceps is derived from the pupa or larva of insects infected by the entomopathogenic fungi Cordyceps. The fruiting body has been used as an anti-cancer and anti-inflammatory ingredient in traditional Chinese medicine. The biochemical characteristics of protease isolated from Cordyceps nutans were investigated in this study. The culturing period for production of protease by C. nutans was 10days. The acidity was pH 7.0, and the temperature was $25^{\circ}C$. The carbon and nitrogen sources for the production of the protease were glucose and yeast extract, respectively. The ratio of C/N was 2% glucose and 0.6% yeast extract. 0.06% $CuSO_4$ was used as the inorganic salt. The investigation into the acidity of the protease produced by C. nutans revealed that the optimal pH and temperature were pH 7.0 and $30^{\circ}C$. The stability of the protease was shown as pH 6.0~9.0 and $30{\sim}50^{\circ}C$. The investigation into the influence of the metal ions on the enzyme activation of C. nutans revealed that it was inhibited in $ZnSO_4$ and activated in $FeSO_4$.

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Molecular Characterization of Burkholderia Strains Isolated from Rice Cultivars (Oryza sativa L.) for Species Identification and Phylogenetic Grouping

  • Madhaiyan, Munusamy;Poonguzhali, Selvaraj;Kwon, Soon-Wo;Song, Myung-Hee;Sa, Tong-Min
    • Journal of Microbiology and Biotechnology
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    • 제18권6호
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    • pp.1005-1010
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    • 2008
  • The genus Burkholderia consists of extremely versatile bacteria that occupy diverse niches and are commonly encountered in the rhizosphere of crop plants. In this study, we characterized three plant growth promoting strains assigned as Burkholderia sp. using biochemical and molecular characterization. The Burkholderia spp. strains CBMB40, CBPB-HIM, and CBPB-HOD were characterized using biochemical tests, BIOLOG carbon substrate utilization, fatty acid methyl ester analysis, analysis of recA gene sequences, and DNA-DNA hybridization. The results from these studies indicated that the strains CBMB40, CBPB-HIM, and CBPB-HOD can be assigned under Burkholderia vietnamiensis, Burkholderia ubonensis, and Burkholderia pyrrocinia, respectively.

Plant Cell Wall Degradation with a Powerful Fusarium graminearum Enzymatic Arsenal

  • Phalip, Vincene;Goubet, Florence;Carapito, Raphael;Jeltsch, Jean-Marc
    • Journal of Microbiology and Biotechnology
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    • 제19권6호
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    • pp.573-581
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    • 2009
  • The complex enzyme pool secreted by the phytopathogenic fungus Fusarium graminearum in response to glucose or hop cell wall material as sole carbon sources was analyzed. The biochemical characterization of the enzymes present in the supernatant of fungal cultures in the glucose medium revealed only 5 different glycosyl hydrolase activities; by contrast, when analyzing cultures in the cell wall medium, 17 different activities were detected. This dramatic increase reflects the adaptation of the fungus by the synthesis of enzymes targeting all layers of the cell wall. When the enzymes secreted in the presence of plant cell wall were used to hydrolyze pretreated crude plant material, high levels of monosaccharides were measured with yields approaching 50% of total sugars released by an acid hydrolysis process. This report is the first biochemical characterization of numerous cellulases, hemicellulases, and pectinases secreted by F. graminearum and demonstrates the usefulness of the described protein cocktail for efficient enzymatic degradation of plant cell wall.