• Title/Summary/Keyword: high pH

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Quality Characteristics of Commercial Slices of Skate Raja kenojei (국내산과 수입산 시판 홍어회의 이화학적 및 미생물학적 품질 특성에 관한 연구)

  • Cho, Hee-Sook;Kim, Kyung-Hee
    • Journal of the East Asian Society of Dietary Life
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    • v.18 no.2
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    • pp.214-220
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    • 2008
  • The purpose of this study was to investigate the quality characteristics of domestic and imported slices of skates Raja kenojei. Four types of slices of skates Raja kenojei were analyzed for proximate composition, extractive nitrogen, free amino acids, and fatty acids. A large amount of TMAO was detected in the domestic slices of skate. Both the domestic and imported skate contained aerobic bacteria, with approximate levels of 6.6 log CFU/g and 5.1${\sim}$6.5 log CFU/g, respectively. The total free amino acids contents of the domestic and imported skates were 579.7 mg and 387.6${\sim}$496.3 mg, respectively; all samples had high levels of taurine, anserine, lysine, alanine, glycine, proline, ${\beta}$-alanine, and histidine. Eleven different saturated fatty acids were found in the domestic skates whereas the impored skate had 7${\beta}$10 different types of saturated fatty acid. In addition, 16 kinds of domestic skate, and 10${\beta}$15 kinds of imported skate were analyzed for unsaturated fatty acid content. From the overall results, the domestic skate proved to be a better source of amino acid, and had higher levels of aerobic bacteria and fatty acids than the imported skate.

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Characterization of a Novel cry1-Type Gene from Bacillus thuringiensis subsp. alesti Strain LY-99

  • Qi, Xu Feng;Li, Ming Shun;Choi, Jae-Young;Roh, Jong-Yul;Song, Ji Zhen;Wang, Yong;Jin, Byung-Rae;Je, Yeon-Ho;Li, Jian Hong
    • International Journal of Industrial Entomology and Biomaterials
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    • v.18 no.1
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    • pp.18-27
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    • 2009
  • B. thuringiensis strain LY-99 belonging to subsp. alesti (H3a3c), was isolated from Chinese tobacco warehouse and showed significantly high toxicity to Plutella xylostella. For the identification of the cry1-type genes from B. thuringiensis LY-99, an extended multiplex PCRrestriction fragment length polymorphism (PCRRFLP) method was established by using two pairs of universal primers based on the conserved regions of the cry1-type genes to amplify around 2.4 kb cry1-type gene fragments. Then the DNA fragment was cloned into pGEM-T Easy vector and digested with EcoRI and EcoRV enzymes. Through this method, a known cry1-type gene was successfully identified from the reference strain, B. thuringiensis subsp. alesti. In addition, the RFLP patterns revealed that B. thuringiensis LY-99 included a novel cry1A-type gene in addition to cry1Aa, cry1Ac, cry1Be and cry1Ea genes. The novel cry1A-type gene was designated cry1Ah2 (Genbank accession No DQ269474). An inverse PCR method was used to amplify the flank regions of cry1Ah2 gene. Finally, 3143 bp HindIII fragment from B. thuringiensis LY-99 plasmid DNA including 5' region and partial ORF was amplified, and sequence analysis revealed that cry1Ah2 gene from LY-99 showed 89.31% of maximum sequence similarity with cry1Ac1 crystal protein gene. In addition, the deduced amino acid sequence of Cry1Ah2 protein shared 87.80% of maximum identity with that of Cry1Ac2. This protein therefore belongs to a new class of B. thuringiensis crystal proteins.

Optimization of industrial medium for the production of erythritol by candida magnoliae

  • Kim, Seung-Bum;Park, Sun-Young;Seo, Jin-Ho;Ryu, Yeon-Woo
    • 한국생물공학회:학술대회논문집
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    • 2003.10a
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    • pp.268-272
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    • 2003
  • Experiments were carried out to investigate the selection of industrial medium and optimization of fermentation process for the production of erythritol by Candida magnoliae SR101. In the batch fermentation, light steep water(LSW) was the best nitrogen source for the industrial production of erythritol. For the optimization of culture condition, the batch culture was performed. When the concentration of LSW was 65 mL/L in the defined medium containing 250 g/L of glucose, 44% of erythritol yield with 110 g/L of erythritol concentration and 0.66 g/L-hr of productivity, respectively were obtained. Two-stage fed-batch culture was performed to improve the volumetric productivity of erythritol. High density cell culture in the growth stage was performed by batch type with 100 g/L glucose and 500 mL/L LSW concentration, respectively. The cell yield was 0.72 g-cell/g-glucose. Productivity of erythritol was increased and concentration of organic acids such as gluconic acid and acetic acid were decreased when initial pH of 6.5 controlled by 28% ammonia water For increasing yield of erythritol, glucose concentration in the production stage was tested. 37% of total erythritol yield with 186 g/L of erythritol concentration and 1.66 g/L-hr of erythritol productivity were obtained when 820 g of glucose powder was directly added for making up 450 g/L of glucose at production stage.

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An Overview of Geoenvironmental Implications of Mineral Deposits in Korea (한반도 광상 성인유형에 따른 환경 특성)

  • 최선규;박상준;이평구;김창성
    • Economic and Environmental Geology
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    • v.37 no.1
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    • pp.1-19
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    • 2004
  • Metallic deposits in Korea have a variety of genetic types such as hydrothermal veins, skarns, hydrothermal replacement and alaskite deposits and so on. Geological, mineralogical and geochemical features including host rock, wall-rock alteration, ore and gangue mineralogy, mineral texture and secondary mineralogy related to weathering process control the environmental signatures of mining areas. The environmental signatures of metallic deposits closed from early 1970s to late 1990s in Korea show complicate geochemistry and mineralogy due to step weathering of primary and secondary minerals such as oxidation-precipitation-remobilization. The potentiality of low pH and high heavy metal Concentration s from acid mine drainage is great in base-metal deposits associated with polymetallic mineralization, breccia-pipe type and Cretaceous hydrothermal Au veins with the amount of pyrite whereas skam, hydrothermal replacement, hydrothermal Cu and Au-Ag vein deposits are in low contamination possibility. The geoenvironmental models reflecting the various geologic features closely relate to disuibution of sulfides and carbonates and their ratios and finally effect on characteristics of environmental signatures such as heavy metal species and their concentrations in acid mine drainage.

An Ecological Study on the Process of Plant Community Formation in Tidal Land (간척지 식물군락형성 과정에 관한 연구 -목포지방을 중심으로-)

  • 김철수
    • Journal of Plant Biology
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    • v.14 no.4
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    • pp.27-33
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    • 1971
  • Information this research an attempt was made to investigate the plant community structure and the process of its formation in the tidal area surrounding Mokpo City the examined area included the stand in Sam-Hak Do wherein sands have inflowed, and the stand in Kat-Ba-Woo which has been left as tidal soil land. Two hundred stands were sampled by making 100m line transects 5m apart and establishing 30cm$\times$30cm quadrates 10m apart on each tape. These data were used to establish frequency, cover degree, density, standing crop (g/$m^2$), contained Cl in the soil, and pH. Results of the research are as following: 1. There were 25 species of plants in the stands from Sam-Hak Do, 18 in the stands from Kat-Ba-Woo, and so 28 species in all. Regardings the importance value, the rank of dominant species is Salicornia herbacea L., Suaeda maritima Dumorties, Diplachne fusca L., Echinochola hispidula Nakai, Cyperus iria L., Setaria lutescens Hubbard in Sam-Hak Do, and Suaeda maritima Dumorties, Echinochloa hispidula Nakai, Aster tripolium L., Scripus maritimus L., Salicornia herbacea L., Diplachne fusca L., in the lands from Kat-Ba-Woo. Among them are five kinds of halophytes Salicornia herbacea L., Suaeda maritima Dumorties, Atriplex Gmelini C.A. Meyer, Aster tripolium L., and Limonium tetragonum Bullock; and two Kinds of naturalized plants Diplachan fusca L., Aster subulata. M. In the stands from Sam-Hak Do there was evidence of a secondary succession phenomena in the presence of Cyperaceae such as Cyperus liria L., Juncus decipiens Nakai, and Fimbristylis longispica Steudal, which could not be found in the stands from Kat-Ba-Woo. 2. On the number of species of vegetation, the further inland from the floodgate the higher the number; that is, the lower the content of Cl the higher the number of species. 3. On the distribution of the vegetation; comparing DFD index and Cl content, the main plants are Salicornia herbacea L., Suaeda maritima Dumorties, Atriplex gmelini C.A. Meyer, Diplachne fuscal, Echinochola hispidula Nakai where the Cl content of soil is more than 13.2%. 4. On the standing crop; Salicornia herbacea L., which has high resistance to salt, was half the total was production of 1090/$m^2$ while Suaeda maritima Dumorties was 1/4, Diplachne fusca L. 1/8, and Echinochloa the least. Analyzing the result, the research indicates that the main factor in plant community formation in tidal land is tolerance for Cl, and that a plan for utilizing the halophytes which are abundant in tidal land should be devised.

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Development of Observation Methods for Density of Stink Bugs in Soybean Field (콩포장에서 노린재류의 밀도조사법 개발)

  • Bae, Soon-Do;Kim, Hyun-Ju;Lee, Geon-Hwi;Park, Sung-Tae
    • Korean journal of applied entomology
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    • v.46 no.1 s.145
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    • pp.153-158
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    • 2007
  • This study was conducted to develope the observing methods for density of stink bugs in soybean reproductive stage. The adults and nymphs of bean bug, Riptortus clavatus, red-banded shield bug, Piezodous hybneri, green stink bug, Nezara antennata, Sole bug, Dolycoris baccarum, and brown marmorated stink bug, Halyomorpha halys were observed by three observing methods such as beating, sweeping net, and visual counting methods in the full bloom (R2), full pod (R4) and beginning maturity (R7) of soybean. As a result, total number of stink bugs observed was the highest with 5,214.2 by beating method, and then was 2,581.8 by visual counting method, and was the lowest with 103.1 by sweeping net method. Total number of stink bugs observed by the beating and visual counting methods was P. hybneri, followed by N. antennata, H. halys, R. clavatus and D. baccarum with clear difference in observed number of each stink bugs while total number of stink bugs observed by sweeping net method was very low in the range of 18 to 23. Accordingly, the observed density of stink bugs exception of R. clavatus adult by beating method was generally high. However, the number of R. clavatus adult was more observed by flushing method than that by beating method from the beginning bloom (R1) to full maturity (R8), and was more observed at morning time than that at afternoon time. Therefore, two observation methods that flushing method for R. clavatus and beating method for the other stink bugs were recommended for the occurring density of stink bugs in soybean because both bean bug and pentatomidae stink bugs have distinct behavior characteristics such as flying and dropping.

Effects of Al2O3 Coating on BiVO4 and Mo-doped BiVO4 Film for Solar Water Oxidation

  • Arunachalam, Maheswari;Yun, Gun;Lee, Hyo Seok;Ahn, Kwang-Soon;Heo, Jaeyeong;Kang, Soon Hyung
    • Journal of Electrochemical Science and Technology
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    • v.10 no.4
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    • pp.424-432
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    • 2019
  • Planar BiVO4 and 3 wt% Mo-doped BiVO4 (abbreviated as Mo:BiVO4) film were prepared by the facile spin-coating method on fluorine doped SnO2(FTO) substrate in the same precursor solution including the Mo precursor in Mo:BiVO4 film. After annealing at a high temperature of 450℃ for 30 min to improve crystallinity, the films exhibited the monoclinic crystalline phase and nanoporous architecture. Both films showed no remarkably discrepancy in crystalline or morphological properties. To investigate the effect of surface passivation exploring the Al2O3 layer, the ultra-thin Al2O3 layer with a thickness of approximately 2 nm was deposited on BiVO4 film using the atomic layer deposition (ALD) method. No distinct morphological modification was observed for all prepared BiVO4 and Mo:BiVO4 films. Only slightly reduced nanopores were observed. Although both samples showed some reduction of light absorption in the visible wavelength after coating of Al2O3 layer, the Al2O3 coated BiVO4 (Al2O3/BiVO4) film exhibited enhanced photoelectrochemical performance in 0.5 M Na2SO4 solution (pH 6.5), having higher photocurrent density (0.91 mA/㎠ at 1.23 V vs. reversible hydrogen electrode (RHE), briefly abbreviated as VRHE) than BiVO4 film (0.12 mA/㎠ at 1.23 VRHE). Moreover, Al2O3 coating on the Mo:BiVO4 film exhibited more enhanced photocurrent density (1.5 mA/㎠ at 1.23 VRHE) than the Mo:BiVO4 film (0.86 mA/㎠ at 1.23 VRHE). To examine the reasons, capacitance measurement and Mott-Schottky analysis were conducted, revealing that the significant degradation of capacitance value was observed in both BiVO4 film and Al2O3/Mo:BiVO4 film, probably due to degraded capacitance by surface passivation. Furthermore, the flat-band potential (VFB) was negatively shifted to about 200 mV while the electronic conductivities were enhanced by Al2O3 coating in both samples, contributing to the advancement of PEC performance by ultra-thin Al2O3 layer.

Making Fish Paste with Yam(Dioscorea japonica Thumb) Powder and Its Characteristics (마 분말을 첨가한 어묵의 제조 및 특성)

  • Kim, Jung-Sun;Byun, Gwang-In
    • Culinary science and hospitality research
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    • v.15 no.2
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    • pp.57-69
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    • 2009
  • This study was conducted the physicochemical and sensory characteristics of fish paste with yam powder(0~5%). The pH of the samples ranged from 6.89 to 7.02, and moisture content ranged from 79.53 to 80.44%. Increasing the amount of yam powder in the fish paste tended to decrease the lightness(L) in Hunter color value while increasing the redness(a) and yellowness(b). For the textural characteristics, the addition of yam powder increased strength, gumminess, cohesiveness and springiness. Fish paste with 3~5% yam powder had good flexibility and wasn't broken even after 4 times folds. In sensory evaluation, the addition of 2% yam powder had the best score in color, taste and overall preference. Therefore, this results suggest that 2% yam powder can be applied to fish paste for the purpose of high quality, preference and functionality.

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Isolation and Identification of Lactic acid Producing Bacteria from Kimchi and Their Fermentation Properties of Soymilk (젖산 생성능이 우수한 김치 유래 젖산균의 분리 및 두유 발효 특성)

  • Lee, Lan-Sook;Jung, Kyung Hee;Choi, Ung-Kyu;Cho, Chang-Won;Kim, Kyung-Im;Kim, Young-Chan
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.42 no.11
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    • pp.1872-1877
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    • 2013
  • Lactic acid bacteria were selected on the basis of lactic acid producing ability from kimchi, a traditional Korean fermented food. Among the initial screening of over 150 strains selected from the sample, 27 strains were selected as lactic acid producing bacteria, and 4 strains were finally selected based on their ability to produce relatively high levels of lactic acid. The four strains were identified as Lactobacillus (L.) plantarum Gk04, Pediococcus pentosaceus Gk07, L. brevis Gk35 and L. curvatus Gk36 by the conventional morphological, cultural, physiological and biochemical characteristics, as well as by 16S rRNA sequence analysis. Among the identified lactic acid bacteria, L. curvatus Gk36 was used for soymilk fermentation. The viable cell counts and acidity values measured for the L. curvatus Gk36 were comparable to the commmercial L. acidopillus. Thus, the L. curvatus Gk36 is a potential probiotic strain to prepare fermented soy products, such as kephir, yogurt, tempeh and soy sauce.

Effects of a Carbohydrase Mixture, Ultrasound, and Irradiation Treatments on the Physical Properties of Defatted Mustard Meal-based Edible Films (탈지 겨자씨로 제조한 가식성 생고분자 필름의 물리적 특성에 대한 탄수화물 가수분해 효소 혼합체, 초음파, 그리고 방사선 처리의 효과)

  • Yang, Hee-Jae;Noh, Bong-Soo;Kim, Jae-Hun;Min, Sea-C.
    • Korean Journal of Food Science and Technology
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    • v.43 no.1
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    • pp.30-38
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    • 2011
  • Effects of depolymerization treatments of a carbohydrase mixture (CM), ultrasound, and irradiation on the physical properties of defatted mustard meal-based edible films (DMM films) were investigated. DMM hydrocolloids were added to CM (0.42% (w/w solution)), treated by ultrasound (500-700 W, 10-30 min) or ${\gamma}$-ray (40-100 kGy) to prepare film-forming solutions. Films were formed by drying. The CM treatment at 0.42% (w/w), pH 5.5, and 40-$50^{\circ}C$ with a 0.5 hr incubation time resulted in the highest colloidal stability in the film-forming solution. The depolymerization treatments did not dramatically change the water vapor permeability of the films. The solubility of the film decreased up to 53.1% by the CM treatment. The ultrasound treatment (700 W-30 min) decreased tensile strength and elongation. The ultrasound treatment (600 W-20 min) resulted in more compact and uniform structures of the films. Flavor profiles were differentiated by the power level and the time of the ultrasound treatment.